Research ArticleGreenhouse Gas Emissions from Cotton Field underDifferent Irrigation Methods and Fertilization Regimes inArid Northwestern China
Jie Wu1 Wei Guo1 Jinfei Feng1 Lanhai Li2 Haishui Yang1
Xiaohua Wang1 and Xinmin Bian1
1 College of Agriculture Nanjing Agricultural University Nanjing 210095 China2 State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and Geography Chinese Academy of SciencesXinjiang 830011 China
Correspondence should be addressed to Xinmin Bian bxmnau163com
Received 19 February 2014 Revised 26 June 2014 Accepted 27 June 2014 Published 16 July 2014
Academic Editor Antonio M De Ron
Copyright copy 2014 Jie Wu et al This is an open access article distributed under the Creative Commons Attribution License whichpermits unrestricted use distribution and reproduction in any medium provided the original work is properly cited
Drip irrigation is broadly extended in order to save water in the arid cotton production region of China Biochar is thought to bea useful soil amendment to reduce greenhouse gas (GHG) emissions Here a field study was conducted to compare the emissionsof nitrous oxide (N
2O) and methane (CH
4) under different irrigation methods (drip irrigation (D) and furrow irrigation (F)) and
fertilization regimes (conventional fertilization (C) and conventional fertilization + biochar (B)) during the cotton growth seasonThe accumulated N
2O emissions were significantly lower with FB DC and DB than with FC by 288 361 and 376 while
accumulated CH4uptake was 2645 2267 and 1542 higher with DC DB and FC than that with FB respectively Irrigation
methods showed a significant effect on total global warming potential (GWP) and yield-scaled GWP (119875 lt 001) DC and DBshowed higher cotton yield water use efficiency (WUE) and lower yield-scaled GWP as compared with FC and FB This suggeststhat in northwestern China mulched-drip irrigation should be a better approach to increase cotton yield with depressed GHG Inaddition biochar addition increased CH
4emissions while it decreased N
2O emissions
1 Introduction
Crop cultivation stimulates greenhouse gas (GHG) emissionsfrom soil to the atmosphere from agricultural practicessuch as irrigation and fertilization which in turn influencesthe biogeochemical process of carbon and nitrogen (N)in the soil The emissions of GHG from crop land havebeen estimated to account for 135 of the anthropogenicemissionsworldwide [1]How to reduceGHGemissions fromagricultural practices without yield loss is an urgent taskfor crop production Improving the cropping practices is arecommended strategy to mitigate greenhouse gas emissionsfrom agricultural soil [1] However this strategy is highlydependent on the crops since the cropping practices variedwith crop species [2] Cotton is one of the major cashcrops delivering natural fibers to textile industries aroundthe world Globally the harvested area of seed cotton is 32
million ha in 2010 [3] Considerable field experiments havedocumented large amount of N
2O emitted from cotton field
due to high N fertilizer input and immoderate irrigation [4ndash6]
Soil moisture is one of the key factors affecting GHGproduction in agricultural soil An optimal irrigation canreduce GHG emissions by regulating the N and carbonturnover process in soil via manipulating soil moisture Mostof the cotton production is situated in the semiarid orarid areas where water-saving irrigation is a key issue forthe cotton cultivation Drip irrigation is one of the water-saving irrigation approaches broadly extended in semiaridor arid regions since it can reduce surface evaporationsurface runoff and deep percolation [7] Water and mineralN fertilizer are directly supplied to the crop root zone throughdrip irrigation system to adapt to the crop requirementshence improving the water and N use efficiency Therefore
Hindawi Publishing Corporatione Scientific World JournalVolume 2014 Article ID 407832 10 pageshttpdxdoiorg1011552014407832
2 The Scientific World Journal
drip irrigation may have a large influence on the nitrogenand carbon turnover in soil and reduce the N fertilizer-induced N
2O or carbon-related greenhouse gas (eg CH
4)
production in relation to conventional furrow irrigationFor instance several studies showed that drip irrigationsignificantly decreased the N
2O emission from tomato and
melon field as compared with furrow irrigation [8ndash10]However the N fertilizer application rate is much higher incotton cultivation than that in the aforementioned cropsTheN fertilizer application rate is approximately 300 kgNhaminus1 incotton production area of China which is nearly two timeshigher than that in previous studies (120ndash175 kgNhaminus1) [8 9]Thus it is still unknown what the impact of drip irrigationwould be onN
2Oemission under highN fertilizer application
conditionsBiochar is the byproduct of biomass pyrolysis one of
the technologies used to produce bioenergy It has beensuggested that biochar can be a useful soil amendment toimprove soil physiochemical properties and crop yield aswell as to increase soil carbon storage and reduce GHGemissions [11ndash13] Biochar addition could mitigate or inhibitN2O emission in most studies for increased adsorption of
NH4
+ or changes in pH that alter the N2O-to-N
2ratio during
denitrification [14ndash16] However the effects of biochar onCH4emissions have yet been inconsistent Previous study
showed that biochar addition to the upland soil increasedCH4emissions by 37 [17] On the other hand CH
4uptake
increased in some studies after biochar additions [18 19]The results for the observed changes in CH
4emissions may
contradictorily depend on soil water content soil type andbiochar type Till now few data are available to support theseconclusions on the field scale especially for uplands
Drip irrigation with plastic film mulching is widelyrecommended as a replacement of the traditional furrowirrigation because seasonal shortage of irrigation water andlow temperature have become critical factors limiting theproductivity of cotton crop in this area However only afew studies investigated the characteristics of CO
2 N2O and
CH4emissions from cotton field under drip irrigation in
China [20ndash22] To our knowledge there are nopublishedfieldstudies on the effect of biochar addition on GHG emissionsfrom cotton field Thus the objectives of this study are to(a) investigate the characteristics of N
2O and CH
4emissions
from cotton field under different irrigation methods andfertilization regimes and (b) compare the integrated effects ofdifferent irrigation methods and fertilization regimes on theGHG emissions
2 Materials and Methods
21 The Study Site A field experiment was carried out at theexperimental farm of Shihezi University in Xinjiang Province(45∘191015840 N 116∘341015840 E 433ndash437m in elevation) which locates inthe primary cotton production region of China This regionhas a dry continental climate with mean annual temperatureof 8∘C and precipitation of 150mm most of which occursfrom June to September The main crops in this area arecotton wheat and maize The soil in the experiment site is
heavy loam and the previous crop is cotton Some chemicalproperties for the topsoil sampled at 0ndash15 cm depth were asfollows soil organic matter 131 gsdotkgminus1 total soil nitrogen09 gsdotkgminus1 available soil phosphorus 663mgsdotkgminus1 availablesoil potassium 1698mgsdotkgminus1
22 Treatments and Field Work The field experiment com-prised two factors during the cotton growing seasons of 2011including different irrigation methods (furrow irrigationand drip irrigation) and fertilization regimes (conventionalfertilization and conventional fertilization + biochar) Thefour treatments included (1) FC furrow irrigation (mulch-free) with conventional fertilization (2) DC drip irrigation(plastic filmmulching)with conventional fertilization (3) FBfurrow irrigation (mulch-free) with conventional fertilization+ biochar (4) DB drip irrigation (plastic filmmulching) withconventional fertilization + biochar The experiment was arandomized block design with three replicates The size ofeach experimental plot was 40m2 (5m times 8m) As shown inFigure 1 the cotton was planted in narrow row spacing of30 cm and wide row spacing of 60 cm with plant spacing of10 cm For treatments of DC and DB transplant plastic filmin width of 120 cm covered four rows
Seeds (Xinjiang cotton cv number 36)were sownonApril27 and emerged on May 5 The fertilization and irritationwere applied according to the local farming regime Theirrigation volumes were 4500m3 haminus1 and 6000m3 haminus1 fordrip irrigation treatments (DC andDB) and furrow irrigationtreatments (FC and FB) respectively The biochar (SanliNew Energy China) was applied as basal fertilizer at arate of 7500 kg hmminus2 Chemical fertilizer was applied at thesame total rate of diammonium phosphate (300 kgsdothmminus2)urea (555 kgsdothmminus2) and potassium dihydrogen phosphate(90 kgsdothmminus2) for all treatments Diammonium phosphatewas applied as basal fertilizer The percentages for dressingfertilizer were different for two irrigation methods thetopdressing was applied in three times from June 10 to July10 for furrow irrigation treatments while the topdressing wasfertigated with the drip irrigation system in several times forthe drip irrigation treatments The detail of fertilization andirrigation for these four treatments was shown in Table 1
23 Investigation of GHG Emissions GHGfluxes from cottonfield were measured using static chamber and gas chro-matography method [23] The size of chambers was 80 cmtimes 80 cm times 45 (90) cm (length times width times height) the heightof chambers was adapted to cotton plant growth The gassampling was carried out between 900 and 1100 hours Gassamples were drawn from the chambers through a three-waystopcock using an airtight syringe with volume of 50mL at 010 20 and 30min after closure and immediately transferredinto 50mL vacuum glass container The GHG fluxes fromall plots were measured at 7-day interval The gas sampleswere analyzed for the concentrations of N
2O and CH
4using
a gas chromatograph (Agilent 7890 Agilent TechnologiesUSA) equipped with an electron capture detector (ECD) anda flame ionization detector (FID) The rates of N
2O and
The Scientific World Journal 3
Table 1 The applications of irrigation and topdressing during the cotton growth period
Irrigation date Drip irrigation treatments Furrow irrigation treatmentsVolume
(m3sdothmminus2) Urea (kgsdothmminus2) Potassium dihydrogen
phosphate (kgsdothmminus2)Volume
(m3sdothmminus2) Urea (kgsdothmminus2) Potassium dihydrogen
phosphate (kgsdothmminus2)610-611 225 30 15 1050 150624-625 300 30 15 1500 300 6073 300 3079-710 375 60 1500 105 30717 450 75723-724 450 75 120081 450 6085-86 450 60 750813 375 45 15821 375 45 15827 300 30 1593 225 15 15910 225
Sampling area
Drip irrigation
tape
Drip irrigation
tape
Plastic film
10 cm
30 cm 30 cm 30 cm 30 cm60 cm 60 cm 60 cm
(a)
Sampling area
10 cm
30 cm 30 cm 30 cm 30 cm60 cm 60 cm 60 cm
(b)
Figure 1 Experimental layout in the cotton field for drip irrigation treatments (DC DB) (a) and furrow irrigation treatments (FC FB) (b)
4 The Scientific World Journal
CH4flux were calculated by the linear increase of the gas
concentration at each sampling time (0 10 20 and 30min)sample sets were rejected unless the correlation coefficient(R2) for the linear regression is greater than 09 (07 for smallflux rates) All flux rates were adjusted for air temperature airpressure and area and volume of the chamber [24] AverageGHG fluxes were calculated by triplicate plots Seasonalaccumulation amounts of GHG emissions were calculated bythe emissions between every two adjacent intervals of themeasurements
24 Soil Temperature Moisture and Mineral N ContentSoil temperature and soil moisture were measured at fourdifferent points near the area covered by the chamber Soiltemperature was taken at 5 cm depth Soil moisture wasdetermined using a TDR (time domain reflectometer) [25]
Surface soil samples (0ndash20 cm) at the experiment plotsclose to the chamber covered area were collected for theanalysis of soil mineral N (ammonium and nitrate) contentsat the same day as the gas sampling during the cotton growthseason Fresh soil samples were extracted with 001M CaCl
2
in a 1 10 ratio of soil to extractant The concentrations ofammonium and nitrate in the extract were analyzed usingcontinuous flow analytical system [26] Cotton yield wasrecorded at cotton harvest
25 Statistical Analyses Differences in seasonal N2O and
CH4emissions soil temperature soil Nmineral contents and
cotton yield as affected by irrigationmethods and fertilizationregimes were examined by using a two-way analysis ofvariance (ANOVA) The statistical analysis was carried outusing SPSS 200 (IBM SPSS Statistics Chicago IL USA)
3 Results
31 Soil Characteristics CottonYield andWaterUse EfficiencyThe soil moisture under FC and FB was significantly higherthan that under DC and DB on June 30 July 14 and July 28while on other days the soil moisture with FC and FB wasclose to that with DC and DB (Figure 2(a)) The soil tem-peratures during cotton growing season were significantlyhigher with DC and DB than with FC and FB during thebud stage (119875 lt 005) (Table 2) As compared with FC DCshowed significantly lower soil temperature during floweringand boll-forming stage (119875 lt 005) (Table 2) Howeverfertilization regimes had no effect on soil temperature Thesoil NO
3
minus-N contents were significantly higher with FC andFB than with DC and DB during the bud stage and thatwith FB was significantly higher than those with FC DC andDB during the flowering and boll-forming stage (119875 lt 005)(Table 2 Figure 3(b)) whichwas caused by the topdressing ofN fertilizer in furrow irrigation plots This topdressing eventalso led to a peak in soil NH
4
+-N contents with FC and FB onJune 23 and June 30 (Figure 3(c))
Although there was no significant difference betweenthe cotton yield among these four treatments the wateruse efficiency (WUE) calculated on cotton yield per unitirrigation volume was significantly higher with DC and DB
than that with FCby 538 and 602 respectively (119875 lt 005)(Table 3)
32 N2O Fluxes The N
2O flux rates with FC varied from
70 120583gmminus2 hminus1 to 3209 120583gmminus2 hminus1 during the cotton grow-ing season with two flux peaks on June 30 and July 21(Figure 4(a)) As compared with FC the N
2O flux rates of
FB were relatively stable and lower Under DC the N2O
flux rates were relatively lower among the sampling datescomparing to FC except a flux peak on August 9 On mostdays the N
2O flux rates with DB were close to that with
DC (Figure 4(a)) The accumulated N2O emissions during
the cotton growing season were significantly lower with FBDC and DB than that with FC by 288 361 and 376respectively (119875 lt 005) (Table 4) At different growth stagesthe highest N
2O flux rate under FC DC and DB appeared
at the flowering and boll-forming stage while FB appearedat the bud stage (Figure 4(b)) The N
2O flux rate with FC
performed differently with other three treatments at theflowering and boll-forming stage and the bud stage (119875 lt005) No significant difference was observed between DCand DB during the whole period
33 CH4Fluxes The CH
4flux rates under FC DC and
DB were below zero on most sampling days indicating thatcotton fields were the sink of CH
4except under FB for most
of the time of the cotton growing season (Figure 5(a)) TheCH4flux rates were similar under the four treatments in
May and June but diverged after June The highest uptake ofCH4appeared at the flowering and boll-forming stage under
FC and DB while it appeared at the bud stage under DC(Figure 5(b)) The accumulated CH
4emissions during the
cotton growing season were significantly lower with DC andDB than that with FB by 2645 and 2267 respectively(119875 lt 005) (Table 4) Although the accumulated CH
4
emission under FC was 1542 lower than that with FB therewas little difference between the two treatments
34 Yield-Scaled GWP The total GWP of N2O and CH
4
emissions during cotton growing season was 10289 1462343509 and 49649 under treatments of DC DB FC and FBrespectively (Figure 6(a)) Cotton fields under DC DB andFC were all sinks for CH
4 which reduced the contribution
of N2O emission to the overall GWP by 683 539
and 144 respectively The yield-scaled GWP calculated byGWP per unit cotton yield with FC and FB were significantlyhigher than those with DC and DB (119875 lt 001) (Figure 6(b))As compared with FC DC and DB were 801 and 722lower in yield-scaled GWP respectively Irrigation methodsshowed extremely significant effect on the total GWP andyield-scaled GWP (119875 lt 001) while fertilization regimes hadno effect on both
4 Discussion
In the present study it was observed that the soil temperatureduring cotton growing season was higher with DC and DBthan with FC and FB in most of the time during cotton
The Scientific World Journal 5
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 10
10
20
30
40
FCDCFB
DB
0
30
60
90
120
Prec
ipita
tion
(mm
)
Precipitation
Volu
met
ric so
il w
ater
cont
ent (
)
(a)
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 10
500
1000
1500
2000
FC FBDC DB
Irrig
atio
n vo
lum
e (m
3ha
minus1)
(b)
Figure 2 Effects of different irrigation methods and fertilization regimes on soil moisture precipitation and volume of irrigation waterduring cotton growing season
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 110
15
20
25
30
35
FCDC
FBDB
Soil
tem
pera
ture
(∘C)
(a)
FCDC
FBDB
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 10
50
100
150
200
250
NO
3ndashN
(mg k
gminus1)
(b)
FCDC
FBDB
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 10
2
4
6
NH
3ndashN
(mg k
gminus1)
(c)
Figure 3 Effects of different irrigation methods and fertilization regimes on soil temperature and mineral N contents during cotton growingseason
growing season for the plastic film mulching A similarresult was found in the previous study for different irrigationmethods in maize field in China [27]The plastic film usuallyprevents the evaporation of soil moisture [22] However thedifference of the soil moisture between four treatments wasprimarily attributed to the water supply regimes (Figure 2)The plastic film showed little effect on maintenance of soilmoisture in the present study Biochar can efficiently retain
soil moisture due to its special physical structure [18] whichwas consistent with our results under DC and DB
The emissions of N2O and CH
4from cotton field were
investigated under different irrigation methods and fertil-ization regimes in an arid area of northwestern China Theaccumulated N
2O emissions during cotton growth season in
this study were lower than that from semiarid cotton fieldin northern China [4] and arid cotton fields in Uzbekistan
6 The Scientific World Journal
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 10
100
200
300
400
FCDC
FBDB
N2O
(120583g m
minus2
hminus1)
(a)
Seedling stage Bud stage Flowering and boll-forming stage
Boll opening 0
30
60
90
120
FCDC
FBDB
stage
N2O
(120583g m
minus2
hminus1)
(b)
Figure 4 Effects of different irrigation methods and fertilization regimes on N2O flux rates during cotton growing season
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 1
0
5
10
CH4
(mg m
minus2
hminus1)
minus5
minus10
FCDC
FBDB
(a)
Seedling stage Bud stage Flowering and boll-forming stage
Boll opening
00
15
30
minus15
minus30
stage
CH4
(mg m
minus2
hminus1)
FCDC
FBDB
(b)
Figure 5 Effects of different irrigation methods and fertilization regimes on CH4flux rates during cotton growing season
[6] but higher than the N2O emissions from semiarid cotton
field in Pakistan [5] The variance in N2O emission among
different ecosites might be attributed to the difference in Nfertilizer application rate irrigation climate factors and soilproperties [28ndash33] Here lower level of N
2O emission from
cotton field was found under FB DC and DB in relation toFC with a high N fertilizer application rate (300 kgNhaminus1)(Table 4)The relatively lowerN
2Oemission from cotton field
under drip irrigation treatments was mainly attributed to thewater supply regime and N fertilizer dressing method (so-called fertigation) in drip irrigation system which favoreddecrease in N
2O emission In detail the soil moisture was
lower in cotton field with drip irrigation treatments than thatwith FC during the bud stage which was the main fertiliza-tion time of FC Previous studies reported that soilmoisture isa key factor in regulation of N
2O emission from agricultural
soil For instance theN2Oemissionwas enhanced alongwith
increased soil moisture in a given range due to the improveddenitrification [34ndash36] Therefore the relatively lower soilmoisture in cotton field withDC andDB during the bud stagecould reduce the N
2O emission more effectively than that
with FC Furthermore the decreased N fertilizer was directly
fertigated to the rhizosphere of cotton plants in drip irrigationtreatments with more times but less application rate pertimeThis N fertilizer dressing method could also improve Nuptake of cotton plant but decrease the soil inorganic N pool(NO3
minus-N and NH4
+-N) (Table 2) and hence reduce N sourceforN2Oemission whichwas significantly correlatedwith soil
N [37] However the observed reduction in N2O emission
caused by drip irrigationwas less than that in previous studiesconducted in the melon and tomato fields [8ndash10] This mightbe related to higher N fertilizer application rate in this study(300 kgNhaminus1) suggesting that the mitigation effect of dripirrigation onN
2Omay be depressed with a higher N fertilizer
application rateAlthough FB and FC used the same irrigation system
FB showed lower N2O emission than FC for the addition of
biochar A similar result was found in wheat field [14 15]However the effect of biochar on N
2O emissions under DB
and DC was covered up by the effect of drip irrigationBiochar had been shown to efficiently retain NH
4
+ via cationexchange by its developed specific surface area and surfacenegative charge density [38] Then the retained N wouldbe slowly released for plant growth thus biochar could
The Scientific World Journal 7
FC DC FB DB
0
500
1000
1500G
WP
(kg
CO2
eqha
minus1)
minus500
CH4
N2O
(a) Overall GWP
FC DC FB DB0
100
200
300
400
500
Yiel
d-sc
aled
GW
P (k
gCO
2eq
haminus1)
(b) Yield-scaled GWP
Figure 6 Overall GWP of GHGs (a) and yield-scaled GWP (b) for different treatmentsThe error bar in (a) was the standard error of overallGWP of N
2O and CH
4emissions
Table 2 Effects of different irrigation methods and fertilization regimes on major soil characteristics Values are means plusmn standard deviationof three replicates Different small letters in the same column refer to significant difference between treatments at 119875 lt 005 level
Seedling stage Bud stage Flowering and boll-forming stage Boll opening stageSoil moisture ()
FC 1679 plusmn 037b 1863 plusmn 025a 2046 plusmn 104a 1600 plusmn 125bDC 1728 plusmn 005b 1224 plusmn 013c 1979 plusmn 100a 1881 plusmn 113aFB 1819 plusmn 035ab 1892 plusmn 035a 1952 plusmn 085a 1416 plusmn 150bDB 1965 plusmn 071a 1493 plusmn 069b 2311 plusmn 082a 1870 plusmn 156a
Soil temperature (∘C)FC 2401 plusmn 033a 2455 plusmn 012b 212 plusmn 012b 1853 plusmn 010aDC 2398 plusmn 012a 2629 plusmn 025a 2255 plusmn 015a 1829 plusmn 027aFB 2428 plusmn 019a 2441 plusmn 036b 2178 plusmn 037ab 1803 plusmn 037aDB 2392 plusmn 009a 2580 plusmn 037a 2211 plusmn 033ab 1800 plusmn 005a
Soil NO3
minus-N (mg kgminus1)FC 10082 plusmn 403a 14582 plusmn 352a 5638 plusmn 668b 2694 plusmn 418aDC 10844 plusmn 339a 1980 plusmn 144b 4611 plusmn 129b 3877 plusmn 515aFB 9824 plusmn 686a 15594 plusmn 1238a 7694 plusmn 249a 3726 plusmn 012aDB 10475 plusmn 531a 2554 plusmn 080b 4113 plusmn 490b 3919 plusmn 645a
Soil NO4
+-N (mg kgminus1)FC 214 plusmn 028a 198 plusmn 041ab 138 plusmn 019a 046 plusmn 008aDC 214 plusmn 021a 107 plusmn 013b 096 plusmn 001a 036 plusmn 008aFB 217 plusmn 005a 229 plusmn 016a 124 plusmn 024a 034 plusmn 005aDB 204 plusmn 011a 129 plusmn 006b 101 plusmn 012a 057 plusmn 016a
Table 3 Effects of different irrigationmethods and fertilization regimes on cotton yield and water use efficiency Values are means plusmn standarddeviation of three replicates Different small letters in the same column refer to significant difference between treatments at 119875 lt 005 level
FC DC FB DBCotton yield (Mg haminus1) 176 plusmn 016a 202 plusmn 010a 194 plusmn 017a 211 plusmn 014aWater use efficiency (kgmminus3) 029 plusmn 003b 045 plusmn 002a 032 plusmn 003b 047 plusmn 003a
8 The Scientific World Journal
Table 4 Effects of different irrigation methods and fertilizationregimes on accumulated N2O and CH4 emissions during cottongrowing season Values are means plusmn standard deviation of threereplicates Different small letters in the same column refer tosignificant difference between treatments at 119875 lt 005 level
N2O (kg haminus1) CH4 (kg haminus1)
FC 171 plusmn 013a minus292 plusmn 096abDC 109 plusmn 011b minus887 plusmn 185bFB 121 plusmn 007b 539 plusmn 491aDB 104 plusmn 006b minus684 plusmn 107b
coordinate the mineral N availability and plant uptake Thiswould reduce the amount of N available for denitrificationand lost as N
2O [18] On the other hand decreases in
emissions of N2O in soil amended with biochar might be
attributed to improved aeration and porosity for its developedmicrostructure which might lead to lower denitrificationrates and alter the N
2O-to-N
2ratio during denitrification
[16]The present study indicated that the arid cotton fields
under FC DC and DB were the sinks of CH4 while FB was
the source of CH4 This was consistent with the results of
previous studies with different irrigation methods conductedin upland field [39ndash41] However drip irrigation was asource of CH
4in the study in cotton field [22] which was
inconsistent with the present results This might be relatedto the different rate of irrigation and fertilization Uplandfields are normally net sinks for CH
4 since the consumption
exceeds the production in CH4[42] The dry soil in upland
field limited the CH4emission however it did have a
possibility to become a source after rainfall within severaldays orweeks [43 44] Comparing theCH
4emission between
DC and FC it was shown that DC increased the uptakeof CH
4for the relative lower soil moisture in most of the
time during cotton growing season (Figure 2(a)) The mainfactor affectingCH
4uptake in summerwas soilmoisture [45]
which plays a critical role inCH4consumption [46] Decrease
in soil moisture enhanced CH4oxidation through improving
CH4diffusion from atmosphere into soil pore spaces [47] and
through gas diffusivity to control microbial oxidation whichchanges inversely with soil moisture [48 49]
In our study the addition of biochar increased CH4
emissions by 2846 higher with FB than that with FC whilethe uptake of CH
4with DB was 229 lower than that with
DC The result was in good agreement with previous studythat biochar addition promoted CH
4emissions of the upland
soil [17] However other studies had reported that biocharamendment reduces CH
4emissions as compared with the
control [18 19] The inconsistence might be attributed to thesoil type agricultural management and biochar type On onehand the addition of biochar increased the substrate sup-ply and created a favorable environment for methanogenicactivity On the other hand the CH
4emission from acid
soil was usually much lower than that from neutral soil[50] Biochar addition could increase soil PH which was abenefit for methanogenic bacteria Furthermore increasedsoil aeration due to increased porosity could increase CH
4
diffusion Biochar might play a more important role underpaddy fields compared with straw returning directly whichwould increase CH
4emission obviously [51]
There was significant difference between drip irrigationtreatments and furrow irrigation treatments in the total GWPof N2O and CH
4emissions (119875 lt 001) while fertilization
regimes showed little effect (Figure 6) The average yield-scaledGWPwas 801 and 722 lowerwithDCandDB thanthat with FC indicating that drip irrigation couldmitigate theyield-scaled GHG emissions from cotton field In previousstudies cotton yield was higher with drip irrigation thanthat with furrow irrigation [52] which agreed with ourstudy Although the difference of cotton yield between fourtreatments was insignificant WUE was significantly higherwith DC and DB than that with FC by 538 and 602respectively (119875 lt 005) (Table 3) WUE represented inthis study (from 0263 kgmminus3 to 0527 kgmminus3) were lowerthan that from the studies in Turkey where it rangedfrom 0508 kgmminus3 to 0648 kgmminus3 or from 076 kgmminus3 to146 kgmminus3 [52 53]The variance inWUE in different ecositescould be related to climate plant number varietal differencesand irrigation amount [54] It indicated that drip irrigationsignificantly increased WUE of cotton plants in relation tofurrow irrigation The relative higher WUE with DC and DBwas related to improved fertilizer efficiency and depressedleaching potential in drip irrigation system [55]
5 Conclusions
Irrigation methods significantly affected the GHG emissionsfrom cotton field in arid northwestern China Biochar addi-tion increased CH
4emissions and decreased N
2O emissions
The water supply and N fertilizer dressing method played akey role in regulating gas emissions Drip irrigation treat-ments (DC and DB) remarkably reduced GHG emissionscompared with furrow irrigation treatments (FC and FB) Inaddition drip irrigation treatments (DC and DB) had higheryield and WUE compared to furrow irrigation treatments(FC and FB) Thus mulched-drip irrigation with conven-tional fertilization or conventional fertilization + biocharshould be a better approach to increase cotton yield withdepressed GHG emissions in arid northwestern China
Abbreviations
GHG Greenhouse gasGWP Global warming potentialWUE Water use efficiency
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgment
This work was financially supported by the opened subjectof Xinjiang Key Laboratory of Water Cycle and Utilization inArid Zone (Grant no XJYS0907-2010-03)
The Scientific World Journal 9
References
[1] IPCC Climate Change 2007 The Physical Science Basis Cam-bridge University Press Cambridge UK 2007
[2] A F Bouwman L J M Boumans and N H Baffes GlobalEstimates of Gaseous Emissions of NH
3 NO and N
2O from
Agricultural Land Food and Agriculture Organisation RomeItaly 2001
[3] FAOSTAT 2002 httpfaostatfaoorg[4] C Liu X Zheng Z Zhou et al ldquoNitrous oxide and nitric oxide
emissions from an irrigated cotton field in Northern ChinardquoPlant and Soil vol 332 no 1-2 pp 123ndash134 2010
[5] TMahmood RAli J Iqbal andURobab ldquoNitrous oxide emis-sion from an irrigated cotton field under semiarid subtropicalconditionsrdquo Biology and Fertility of Soils vol 44 no 5 pp 773ndash781 2008
[6] C Scheer R Wassmann K Kienzler N Ibragimov andR Eschanov ldquoNitrous oxide emissions from fertilized irri-gated cotton (Gossypium hirsutum L) in the Aral Sea BasinUzbekistan influence of nitrogen applications and irrigationpracticesrdquo Soil Biology and Biochemistry vol 40 no 2 pp 290ndash301 2008
[7] J Li J Zhang and L Ren ldquoWater and nitrogen distributionas affected by fertigation of ammonium nitrate from a pointsourcerdquo Irrigation Science vol 22 no 1 pp 19ndash30 2003
[8] C M Kallenbach D E Rolston and W R Horwath ldquoCovercropping affects soil N
2O and CO
2emissions differently
depending on type of irrigationrdquo Agriculture Ecosystems andEnvironment vol 137 no 3-4 pp 251ndash260 2010
[9] L Sanchez-Martın A Arce A Benito L Garcia-Torres andA Vallejo ldquoInfluence of drip and furrow irrigation systems onnitrogen oxide emissions from a horticultural croprdquo Soil Biologyand Biochemistry vol 40 no 7 pp 1698ndash1706 2008
[10] L Sanchez-Martın A Meijide L Garcia-Torres and A VallejoldquoCombination of drip irrigation and organic fertilizer formitigating emissions of nitrogen oxides in semiarid climaterdquoAgriculture Ecosystems and Environment vol 137 no 1-2 pp99ndash107 2010
[11] J Lehmann ldquoBio-energy in the blackrdquo Frontiers in Ecology andthe Environment vol 5 no 7 pp 381ndash387 2007
[12] M Fowles ldquoBlack carbon sequestration as an alternative tobioenergyrdquo Biomass and Bioenergy vol 31 no 6 pp 426ndash4322007
[13] M Rondon J A Ramirez and J Lehmann ldquoCharcoal additionsreduce net emissions of greenhouse gases to the atmosphererdquo inProceedings of the 3rd USDA Symposium on Greenhouse Gasesand Carbon Sequestration p 208 Baltimore Md USA March2005
[14] A Aguilar-Chavez M Dıaz-Rojas M del Rosario Cardenas-Aquino L Dendooven and M Luna-Guido ldquoGreenhouse gasemissions from a wastewater sludge-amended soil cultivatedwith wheat (Triticum spp L) as affected by different applicationrates of charcoalrdquo Soil Biology and Biochemistry vol 52 pp 90ndash95 2012
[15] S Castaldi M Riondino S Baronti et al ldquoImpact of biocharapplication to a Mediterranean wheat crop on soil microbialactivity and greenhouse gas fluxesrdquo Chemosphere vol 85 no9 pp 1464ndash1471 2011
[16] B P Singh B J Hatton B Singh A L Cowie and A KathurialdquoInfluence of biochars on nitrous oxide emission and nitrogenleaching from two contrasting soilsrdquo Journal of EnvironmentalQuality vol 39 no 4 pp 1224ndash1235 2010
[17] J Wang X Pan Y Liu X Zhang and Z Xiong ldquoEffects ofbiochar amendment in two soils on greenhouse gas emissionsand crop productionrdquo Plant and Soil vol 360 no 1-2 pp 287ndash298 2012
[18] K Karhu T Mattila I Bergstrom and K Regina ldquoBiocharaddition to agricultural soil increased CH
4uptake and water
holding capacitymdashresults from a short-term pilot field studyrdquoAgriculture Ecosystems and Environment vol 140 no 1-2 pp309ndash313 2011
[19] C Scheer P R Grace D W Rowlings S Kimber and L vanZwieten ldquoEffect of biochar amendment on the soil-atmosphereexchange of greenhouse gases from an intensive subtropicalpasture in northernNew SouthWales AustraliardquoPlant and Soilvol 345 no 1 pp 47ndash58 2011
[20] Z Li R Zhang X Wang J Wang C Zhang and C TianldquoCarbon dioxide fluxes and concentrations in a cotton fieldin northwestern China effects of plastic mulching and dripirrigationrdquo Pedosphere vol 21 no 2 pp 178ndash185 2011
[21] Q Zhang L Yang J Wang H Luo Y Zhang and WZhang ldquoEffects of different irrigation methods and fertilizationmeasures on soil respiration and its component contribution incotton field in arid regionrdquo Scientia Agricultura Sinica vol 25no 12 pp 2420ndash2430 2012 (Chinese)
[22] Z Li R Zhang X Wang F Chen D Lai and C Tian ldquoEffectsof plastic film mulching with drip irrigation on N
2O and CH
4
emissions fromcotton fields in arid landrdquo Journal of AgriculturalScience 2013
[23] FAOIAEA Measurement of Methane and Nitrous Oxide Emis-sion from Agriculture A Joint Undertakong by the Food andAgriculture Organization of United Nations and InternationalAtomic Energy Agency International Atomic Energy AgencyVienna Austria 1992
[24] Y Huang J Jiang L Zong Q Zhou R L Sass and F MFisher ldquoInfluence of planting density and precipitation on N
2O
emission from a winter wheat fieldrdquo Environmental Science vol22 no 6 pp 20ndash23 2001 (Chinese)
[25] G C Topp J L Davis and A P Annan ldquoElectromagneticdetermination of soil water content measurements in coaxialtransmission linesrdquoWater Resources Research vol 16 no 3 pp574ndash582 1980
[26] R Lu Soil Agricultural Chemistry Analytical Method ChinaAgricultural Science and Technology Press Beijing China2000
[27] L Zhou F Li S Jin and Y Song ldquoHow two ridges andthe furrow mulched with plastic film affect soil water soiltemperature and yield of maize on the semiarid Loess Plateauof Chinardquo Field Crops Research vol 113 no 1 pp 41ndash47 2009
[28] J Clemens M P Schillinger H Goldbach and B HuweldquoSpatial variability of N
2O emissions and soil parameters of an
arable silt loammdasha field studyrdquo Biology and Fertility of Soils vol28 no 4 pp 403ndash406 1999
[29] K InubushiM A Barahona andK Yamakawa ldquoEffects of saltsand moisture content on N
2O emission and nitrogen dynamics
in Yellow soil and Andosol in model experimentsrdquo Biology andFertility of Soils vol 29 no 4 pp 401ndash407 1999
[30] B J Joslashrgensen and R N Joslashrgensen ldquoField-scale and laboratorystudy of factors affecting N
2O emissions from a rye stubble field
on sandy loam soilrdquo Biology and Fertility of Soils vol 25 no 4pp 366ndash371 1997
[31] A R Mosier and Z Zhu ldquoChanges in patterns of fertilizernitrogen use in Asia and its consequences for N
2O emissions
10 The Scientific World Journal
from agricultural systemsrdquo Nutrient Cycling in Agroecosystemsvol 57 no 1 pp 107ndash117 2000
[32] R Ruser H Flessa R Schilling F Beese and J C MunchldquoEffect of crop-specific field management and N fertilizationon N2O emissions from a fine-loamy soilrdquo Nutrient Cycling in
Agroecosystems vol 59 no 2 pp 177ndash191 2001[33] C Song and J Zhang ldquoEffects of soil moisture temperature
and nitrogen fertilization on soil respiration and nitrous oxideemission duringmaize growth period in northeast ChinardquoActaAgriculturae Scandinavica B Soil and Plant Science vol 59 no2 pp 97ndash106 2009
[34] D M Linn and J W Doran ldquoEffect of water-filled pore spaceon carbon dioxide and nitrous oxide production in tilled andnontilled soilsrdquo Soil Science Society of America Journal vol 48no 6 pp 1267ndash1272 1984
[35] X J Liu A R Mosier A D Halvorson C A Reule andF S Zhang ldquoDinitrogen and N
2O emissions in arable soils
effect of tillage N source and soil moisturerdquo Soil Biology andBiochemistry vol 39 no 9 pp 2362ndash2370 2007
[36] L Sanchez-Martın A Vallejo J Dick and U M Skiba ldquoTheinfluence of soluble carbon and fertilizer nitrogen on nitricoxide and nitrous oxide emissions from two contrasting agri-cultural soilsrdquo Soil Biology and Biochemistry vol 40 no 1 pp142ndash151 2008
[37] Z Mu S D Kimura Y Toma and R Hatano ldquoNitrous oxidefluxes from upland soils in central Hokkaido Japanrdquo Journal ofEnvironmental Sciences vol 20 no 11 pp 1312ndash1322 2008
[38] B Liang J Lehmann D Solomon et al ldquoBlack carbon increasescation exchange capacity in soilsrdquo Soil Science Society of AmericaJournal vol 70 no 5 pp 1719ndash1730 2006
[39] P Boeckx and O Van Cleemput ldquoEstimates of N2O and CH
4
fluxes from agricultural lands in various regions in EuroperdquoNutrient Cycling in Agroecosystems vol 60 no 1ndash3 pp 35ndash472001
[40] J A MacDonald U Skiba L J Sheppard et al ldquoThe effectof nitrogen deposition and seasonal variability on methaneoxidation and nitrous oxide emission rates in an upland spruceplantation andmoorlandrdquoAtmospheric Environment vol 31 no22 pp 3693ndash3706 1997
[41] S C Whalen ldquoInfluence of N and non-N salts on atmosphericmethane oxidation by upland boreal forest and tundra soilsrdquoBiology and Fertility of Soils vol 31 no 3-4 pp 279ndash287 2000
[42] J P Megonigal and A B Guenther ldquoMethane emissions fromupland forest soils and vegetationrdquo Tree Physiology vol 28 no4 pp 491ndash498 2008
[43] E A Davidson F Y Ishida and D C Nepstad ldquoEffects ofan experimental drought on soil emissions of carbon dioxidemethane nitrous oxide and nitric oxide in a moist tropicalforestrdquo Global Change Biology vol 10 no 5 pp 718ndash730 2004
[44] F LWang and J R Bettany ldquoMethane emission fromCanadianprairie and forest soils under short term flooding conditionsrdquoNutrient Cycling in Agroecosystems vol 49 no 1ndash3 pp 197ndash2021997
[45] R BrummeandWBorken ldquoSite variation inmethane oxidationas affected by atmospheric deposition and type of temperateforest ecosystemrdquo Global Biogeochemical Cycles vol 13 no 2pp 493ndash501 1999
[46] A P S Adamsen and G M King ldquoMethane consumption intemperate and subarctic forest soils rates vertical zonation andresponses to water and nitrogenrdquo Applied and EnvironmentalMicrobiology vol 59 no 2 pp 485ndash490 1993
[47] M S Castro P A Steudler J M Melillo J D Aber and R DBowden ldquoFactors controlling atmospheric methane consump-tion by temperate forest soilsrdquoGlobal Biogeochemical Cycles vol9 no 1 pp 1ndash10 1995
[48] B C Ball K A Smith L Klemedtsson et al ldquoThe influence ofsoil gas transport properties onmethane oxidation in a selectionof northern European soilsrdquo Journal of Geophysical Research Dvol 102 no 19 pp 23309ndash23317 1997
[49] K A Smith T Ball F Conen K E Dobbie J Masshederand A Rey ldquoExchange of greenhouse gases between soil andatmosphere interactions of soil physical factors and biologicalprocessesrdquo European Journal of Soil Science vol 54 no 4 pp779ndash791 2003
[50] H Feng G Cheng and L An ldquoMicrobial-mediated methanecycle in soils and global change a reviewrdquo Journal of Glaciologyand Geocryology vol 26 no 4 pp 411ndash419 2006 (Chinese)
[51] Y YanDWang and J Zheng ldquoAdvances in effects of biochar onthe soil N
2O and CH
4emissionsrdquo Chinese Agricultural Science
Bulletin vol 29 no 8 pp 140ndash146 2013 (Chinese)[52] OCetin andL Bilgel ldquoEffects of different irrigationmethods on
shedding and yield of cottonrdquo Agricultural Water Managementvol 54 no 1 pp 1ndash15 2002
[53] NDagdelenaH Basalb E Yılmaza T Gurbuza and S AkcayaldquoDifferent drip irrigation regimes affect cotton yield water useefficiency and fiber quality in western Turkeyrdquo AgriculturalWater Management vol 96 no 1 pp 110ndash120 2009
[54] N Ibragimov S R Evett Y Esanbekov B S Kamilov LMirzaev and J P A Lamers ldquoWater use efficiency of irrigatedcotton in Uzbekistan under drip and furrow irrigationrdquo Agri-cultural Water Management vol 90 no 1-2 pp 112ndash120 2007
[55] C R Camp P J Bauer and P G Hunt ldquoSubsurface dripirrigation lateral spacing and management for cotton in thesoutheastern Coastal plainrdquo Transactions of the American Soci-ety of Agricultural Engineers vol 40 no 4 pp 993ndash999 1997
Submit your manuscripts athttpwwwhindawicom
Nutrition and Metabolism
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Food ScienceInternational Journal of
Agronomy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom
Applied ampEnvironmentalSoil Science
Volume 2014
AgricultureAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
PsycheHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BiodiversityInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Plant GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biotechnology Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Forestry ResearchInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of BotanyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
EcologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Veterinary Medicine International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Cell BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
2 The Scientific World Journal
drip irrigation may have a large influence on the nitrogenand carbon turnover in soil and reduce the N fertilizer-induced N
2O or carbon-related greenhouse gas (eg CH
4)
production in relation to conventional furrow irrigationFor instance several studies showed that drip irrigationsignificantly decreased the N
2O emission from tomato and
melon field as compared with furrow irrigation [8ndash10]However the N fertilizer application rate is much higher incotton cultivation than that in the aforementioned cropsTheN fertilizer application rate is approximately 300 kgNhaminus1 incotton production area of China which is nearly two timeshigher than that in previous studies (120ndash175 kgNhaminus1) [8 9]Thus it is still unknown what the impact of drip irrigationwould be onN
2Oemission under highN fertilizer application
conditionsBiochar is the byproduct of biomass pyrolysis one of
the technologies used to produce bioenergy It has beensuggested that biochar can be a useful soil amendment toimprove soil physiochemical properties and crop yield aswell as to increase soil carbon storage and reduce GHGemissions [11ndash13] Biochar addition could mitigate or inhibitN2O emission in most studies for increased adsorption of
NH4
+ or changes in pH that alter the N2O-to-N
2ratio during
denitrification [14ndash16] However the effects of biochar onCH4emissions have yet been inconsistent Previous study
showed that biochar addition to the upland soil increasedCH4emissions by 37 [17] On the other hand CH
4uptake
increased in some studies after biochar additions [18 19]The results for the observed changes in CH
4emissions may
contradictorily depend on soil water content soil type andbiochar type Till now few data are available to support theseconclusions on the field scale especially for uplands
Drip irrigation with plastic film mulching is widelyrecommended as a replacement of the traditional furrowirrigation because seasonal shortage of irrigation water andlow temperature have become critical factors limiting theproductivity of cotton crop in this area However only afew studies investigated the characteristics of CO
2 N2O and
CH4emissions from cotton field under drip irrigation in
China [20ndash22] To our knowledge there are nopublishedfieldstudies on the effect of biochar addition on GHG emissionsfrom cotton field Thus the objectives of this study are to(a) investigate the characteristics of N
2O and CH
4emissions
from cotton field under different irrigation methods andfertilization regimes and (b) compare the integrated effects ofdifferent irrigation methods and fertilization regimes on theGHG emissions
2 Materials and Methods
21 The Study Site A field experiment was carried out at theexperimental farm of Shihezi University in Xinjiang Province(45∘191015840 N 116∘341015840 E 433ndash437m in elevation) which locates inthe primary cotton production region of China This regionhas a dry continental climate with mean annual temperatureof 8∘C and precipitation of 150mm most of which occursfrom June to September The main crops in this area arecotton wheat and maize The soil in the experiment site is
heavy loam and the previous crop is cotton Some chemicalproperties for the topsoil sampled at 0ndash15 cm depth were asfollows soil organic matter 131 gsdotkgminus1 total soil nitrogen09 gsdotkgminus1 available soil phosphorus 663mgsdotkgminus1 availablesoil potassium 1698mgsdotkgminus1
22 Treatments and Field Work The field experiment com-prised two factors during the cotton growing seasons of 2011including different irrigation methods (furrow irrigationand drip irrigation) and fertilization regimes (conventionalfertilization and conventional fertilization + biochar) Thefour treatments included (1) FC furrow irrigation (mulch-free) with conventional fertilization (2) DC drip irrigation(plastic filmmulching)with conventional fertilization (3) FBfurrow irrigation (mulch-free) with conventional fertilization+ biochar (4) DB drip irrigation (plastic filmmulching) withconventional fertilization + biochar The experiment was arandomized block design with three replicates The size ofeach experimental plot was 40m2 (5m times 8m) As shown inFigure 1 the cotton was planted in narrow row spacing of30 cm and wide row spacing of 60 cm with plant spacing of10 cm For treatments of DC and DB transplant plastic filmin width of 120 cm covered four rows
Seeds (Xinjiang cotton cv number 36)were sownonApril27 and emerged on May 5 The fertilization and irritationwere applied according to the local farming regime Theirrigation volumes were 4500m3 haminus1 and 6000m3 haminus1 fordrip irrigation treatments (DC andDB) and furrow irrigationtreatments (FC and FB) respectively The biochar (SanliNew Energy China) was applied as basal fertilizer at arate of 7500 kg hmminus2 Chemical fertilizer was applied at thesame total rate of diammonium phosphate (300 kgsdothmminus2)urea (555 kgsdothmminus2) and potassium dihydrogen phosphate(90 kgsdothmminus2) for all treatments Diammonium phosphatewas applied as basal fertilizer The percentages for dressingfertilizer were different for two irrigation methods thetopdressing was applied in three times from June 10 to July10 for furrow irrigation treatments while the topdressing wasfertigated with the drip irrigation system in several times forthe drip irrigation treatments The detail of fertilization andirrigation for these four treatments was shown in Table 1
23 Investigation of GHG Emissions GHGfluxes from cottonfield were measured using static chamber and gas chro-matography method [23] The size of chambers was 80 cmtimes 80 cm times 45 (90) cm (length times width times height) the heightof chambers was adapted to cotton plant growth The gassampling was carried out between 900 and 1100 hours Gassamples were drawn from the chambers through a three-waystopcock using an airtight syringe with volume of 50mL at 010 20 and 30min after closure and immediately transferredinto 50mL vacuum glass container The GHG fluxes fromall plots were measured at 7-day interval The gas sampleswere analyzed for the concentrations of N
2O and CH
4using
a gas chromatograph (Agilent 7890 Agilent TechnologiesUSA) equipped with an electron capture detector (ECD) anda flame ionization detector (FID) The rates of N
2O and
The Scientific World Journal 3
Table 1 The applications of irrigation and topdressing during the cotton growth period
Irrigation date Drip irrigation treatments Furrow irrigation treatmentsVolume
(m3sdothmminus2) Urea (kgsdothmminus2) Potassium dihydrogen
phosphate (kgsdothmminus2)Volume
(m3sdothmminus2) Urea (kgsdothmminus2) Potassium dihydrogen
phosphate (kgsdothmminus2)610-611 225 30 15 1050 150624-625 300 30 15 1500 300 6073 300 3079-710 375 60 1500 105 30717 450 75723-724 450 75 120081 450 6085-86 450 60 750813 375 45 15821 375 45 15827 300 30 1593 225 15 15910 225
Sampling area
Drip irrigation
tape
Drip irrigation
tape
Plastic film
10 cm
30 cm 30 cm 30 cm 30 cm60 cm 60 cm 60 cm
(a)
Sampling area
10 cm
30 cm 30 cm 30 cm 30 cm60 cm 60 cm 60 cm
(b)
Figure 1 Experimental layout in the cotton field for drip irrigation treatments (DC DB) (a) and furrow irrigation treatments (FC FB) (b)
4 The Scientific World Journal
CH4flux were calculated by the linear increase of the gas
concentration at each sampling time (0 10 20 and 30min)sample sets were rejected unless the correlation coefficient(R2) for the linear regression is greater than 09 (07 for smallflux rates) All flux rates were adjusted for air temperature airpressure and area and volume of the chamber [24] AverageGHG fluxes were calculated by triplicate plots Seasonalaccumulation amounts of GHG emissions were calculated bythe emissions between every two adjacent intervals of themeasurements
24 Soil Temperature Moisture and Mineral N ContentSoil temperature and soil moisture were measured at fourdifferent points near the area covered by the chamber Soiltemperature was taken at 5 cm depth Soil moisture wasdetermined using a TDR (time domain reflectometer) [25]
Surface soil samples (0ndash20 cm) at the experiment plotsclose to the chamber covered area were collected for theanalysis of soil mineral N (ammonium and nitrate) contentsat the same day as the gas sampling during the cotton growthseason Fresh soil samples were extracted with 001M CaCl
2
in a 1 10 ratio of soil to extractant The concentrations ofammonium and nitrate in the extract were analyzed usingcontinuous flow analytical system [26] Cotton yield wasrecorded at cotton harvest
25 Statistical Analyses Differences in seasonal N2O and
CH4emissions soil temperature soil Nmineral contents and
cotton yield as affected by irrigationmethods and fertilizationregimes were examined by using a two-way analysis ofvariance (ANOVA) The statistical analysis was carried outusing SPSS 200 (IBM SPSS Statistics Chicago IL USA)
3 Results
31 Soil Characteristics CottonYield andWaterUse EfficiencyThe soil moisture under FC and FB was significantly higherthan that under DC and DB on June 30 July 14 and July 28while on other days the soil moisture with FC and FB wasclose to that with DC and DB (Figure 2(a)) The soil tem-peratures during cotton growing season were significantlyhigher with DC and DB than with FC and FB during thebud stage (119875 lt 005) (Table 2) As compared with FC DCshowed significantly lower soil temperature during floweringand boll-forming stage (119875 lt 005) (Table 2) Howeverfertilization regimes had no effect on soil temperature Thesoil NO
3
minus-N contents were significantly higher with FC andFB than with DC and DB during the bud stage and thatwith FB was significantly higher than those with FC DC andDB during the flowering and boll-forming stage (119875 lt 005)(Table 2 Figure 3(b)) whichwas caused by the topdressing ofN fertilizer in furrow irrigation plots This topdressing eventalso led to a peak in soil NH
4
+-N contents with FC and FB onJune 23 and June 30 (Figure 3(c))
Although there was no significant difference betweenthe cotton yield among these four treatments the wateruse efficiency (WUE) calculated on cotton yield per unitirrigation volume was significantly higher with DC and DB
than that with FCby 538 and 602 respectively (119875 lt 005)(Table 3)
32 N2O Fluxes The N
2O flux rates with FC varied from
70 120583gmminus2 hminus1 to 3209 120583gmminus2 hminus1 during the cotton grow-ing season with two flux peaks on June 30 and July 21(Figure 4(a)) As compared with FC the N
2O flux rates of
FB were relatively stable and lower Under DC the N2O
flux rates were relatively lower among the sampling datescomparing to FC except a flux peak on August 9 On mostdays the N
2O flux rates with DB were close to that with
DC (Figure 4(a)) The accumulated N2O emissions during
the cotton growing season were significantly lower with FBDC and DB than that with FC by 288 361 and 376respectively (119875 lt 005) (Table 4) At different growth stagesthe highest N
2O flux rate under FC DC and DB appeared
at the flowering and boll-forming stage while FB appearedat the bud stage (Figure 4(b)) The N
2O flux rate with FC
performed differently with other three treatments at theflowering and boll-forming stage and the bud stage (119875 lt005) No significant difference was observed between DCand DB during the whole period
33 CH4Fluxes The CH
4flux rates under FC DC and
DB were below zero on most sampling days indicating thatcotton fields were the sink of CH
4except under FB for most
of the time of the cotton growing season (Figure 5(a)) TheCH4flux rates were similar under the four treatments in
May and June but diverged after June The highest uptake ofCH4appeared at the flowering and boll-forming stage under
FC and DB while it appeared at the bud stage under DC(Figure 5(b)) The accumulated CH
4emissions during the
cotton growing season were significantly lower with DC andDB than that with FB by 2645 and 2267 respectively(119875 lt 005) (Table 4) Although the accumulated CH
4
emission under FC was 1542 lower than that with FB therewas little difference between the two treatments
34 Yield-Scaled GWP The total GWP of N2O and CH
4
emissions during cotton growing season was 10289 1462343509 and 49649 under treatments of DC DB FC and FBrespectively (Figure 6(a)) Cotton fields under DC DB andFC were all sinks for CH
4 which reduced the contribution
of N2O emission to the overall GWP by 683 539
and 144 respectively The yield-scaled GWP calculated byGWP per unit cotton yield with FC and FB were significantlyhigher than those with DC and DB (119875 lt 001) (Figure 6(b))As compared with FC DC and DB were 801 and 722lower in yield-scaled GWP respectively Irrigation methodsshowed extremely significant effect on the total GWP andyield-scaled GWP (119875 lt 001) while fertilization regimes hadno effect on both
4 Discussion
In the present study it was observed that the soil temperatureduring cotton growing season was higher with DC and DBthan with FC and FB in most of the time during cotton
The Scientific World Journal 5
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 10
10
20
30
40
FCDCFB
DB
0
30
60
90
120
Prec
ipita
tion
(mm
)
Precipitation
Volu
met
ric so
il w
ater
cont
ent (
)
(a)
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 10
500
1000
1500
2000
FC FBDC DB
Irrig
atio
n vo
lum
e (m
3ha
minus1)
(b)
Figure 2 Effects of different irrigation methods and fertilization regimes on soil moisture precipitation and volume of irrigation waterduring cotton growing season
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 110
15
20
25
30
35
FCDC
FBDB
Soil
tem
pera
ture
(∘C)
(a)
FCDC
FBDB
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 10
50
100
150
200
250
NO
3ndashN
(mg k
gminus1)
(b)
FCDC
FBDB
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 10
2
4
6
NH
3ndashN
(mg k
gminus1)
(c)
Figure 3 Effects of different irrigation methods and fertilization regimes on soil temperature and mineral N contents during cotton growingseason
growing season for the plastic film mulching A similarresult was found in the previous study for different irrigationmethods in maize field in China [27]The plastic film usuallyprevents the evaporation of soil moisture [22] However thedifference of the soil moisture between four treatments wasprimarily attributed to the water supply regimes (Figure 2)The plastic film showed little effect on maintenance of soilmoisture in the present study Biochar can efficiently retain
soil moisture due to its special physical structure [18] whichwas consistent with our results under DC and DB
The emissions of N2O and CH
4from cotton field were
investigated under different irrigation methods and fertil-ization regimes in an arid area of northwestern China Theaccumulated N
2O emissions during cotton growth season in
this study were lower than that from semiarid cotton fieldin northern China [4] and arid cotton fields in Uzbekistan
6 The Scientific World Journal
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 10
100
200
300
400
FCDC
FBDB
N2O
(120583g m
minus2
hminus1)
(a)
Seedling stage Bud stage Flowering and boll-forming stage
Boll opening 0
30
60
90
120
FCDC
FBDB
stage
N2O
(120583g m
minus2
hminus1)
(b)
Figure 4 Effects of different irrigation methods and fertilization regimes on N2O flux rates during cotton growing season
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 1
0
5
10
CH4
(mg m
minus2
hminus1)
minus5
minus10
FCDC
FBDB
(a)
Seedling stage Bud stage Flowering and boll-forming stage
Boll opening
00
15
30
minus15
minus30
stage
CH4
(mg m
minus2
hminus1)
FCDC
FBDB
(b)
Figure 5 Effects of different irrigation methods and fertilization regimes on CH4flux rates during cotton growing season
[6] but higher than the N2O emissions from semiarid cotton
field in Pakistan [5] The variance in N2O emission among
different ecosites might be attributed to the difference in Nfertilizer application rate irrigation climate factors and soilproperties [28ndash33] Here lower level of N
2O emission from
cotton field was found under FB DC and DB in relation toFC with a high N fertilizer application rate (300 kgNhaminus1)(Table 4)The relatively lowerN
2Oemission from cotton field
under drip irrigation treatments was mainly attributed to thewater supply regime and N fertilizer dressing method (so-called fertigation) in drip irrigation system which favoreddecrease in N
2O emission In detail the soil moisture was
lower in cotton field with drip irrigation treatments than thatwith FC during the bud stage which was the main fertiliza-tion time of FC Previous studies reported that soilmoisture isa key factor in regulation of N
2O emission from agricultural
soil For instance theN2Oemissionwas enhanced alongwith
increased soil moisture in a given range due to the improveddenitrification [34ndash36] Therefore the relatively lower soilmoisture in cotton field withDC andDB during the bud stagecould reduce the N
2O emission more effectively than that
with FC Furthermore the decreased N fertilizer was directly
fertigated to the rhizosphere of cotton plants in drip irrigationtreatments with more times but less application rate pertimeThis N fertilizer dressing method could also improve Nuptake of cotton plant but decrease the soil inorganic N pool(NO3
minus-N and NH4
+-N) (Table 2) and hence reduce N sourceforN2Oemission whichwas significantly correlatedwith soil
N [37] However the observed reduction in N2O emission
caused by drip irrigationwas less than that in previous studiesconducted in the melon and tomato fields [8ndash10] This mightbe related to higher N fertilizer application rate in this study(300 kgNhaminus1) suggesting that the mitigation effect of dripirrigation onN
2Omay be depressed with a higher N fertilizer
application rateAlthough FB and FC used the same irrigation system
FB showed lower N2O emission than FC for the addition of
biochar A similar result was found in wheat field [14 15]However the effect of biochar on N
2O emissions under DB
and DC was covered up by the effect of drip irrigationBiochar had been shown to efficiently retain NH
4
+ via cationexchange by its developed specific surface area and surfacenegative charge density [38] Then the retained N wouldbe slowly released for plant growth thus biochar could
The Scientific World Journal 7
FC DC FB DB
0
500
1000
1500G
WP
(kg
CO2
eqha
minus1)
minus500
CH4
N2O
(a) Overall GWP
FC DC FB DB0
100
200
300
400
500
Yiel
d-sc
aled
GW
P (k
gCO
2eq
haminus1)
(b) Yield-scaled GWP
Figure 6 Overall GWP of GHGs (a) and yield-scaled GWP (b) for different treatmentsThe error bar in (a) was the standard error of overallGWP of N
2O and CH
4emissions
Table 2 Effects of different irrigation methods and fertilization regimes on major soil characteristics Values are means plusmn standard deviationof three replicates Different small letters in the same column refer to significant difference between treatments at 119875 lt 005 level
Seedling stage Bud stage Flowering and boll-forming stage Boll opening stageSoil moisture ()
FC 1679 plusmn 037b 1863 plusmn 025a 2046 plusmn 104a 1600 plusmn 125bDC 1728 plusmn 005b 1224 plusmn 013c 1979 plusmn 100a 1881 plusmn 113aFB 1819 plusmn 035ab 1892 plusmn 035a 1952 plusmn 085a 1416 plusmn 150bDB 1965 plusmn 071a 1493 plusmn 069b 2311 plusmn 082a 1870 plusmn 156a
Soil temperature (∘C)FC 2401 plusmn 033a 2455 plusmn 012b 212 plusmn 012b 1853 plusmn 010aDC 2398 plusmn 012a 2629 plusmn 025a 2255 plusmn 015a 1829 plusmn 027aFB 2428 plusmn 019a 2441 plusmn 036b 2178 plusmn 037ab 1803 plusmn 037aDB 2392 plusmn 009a 2580 plusmn 037a 2211 plusmn 033ab 1800 plusmn 005a
Soil NO3
minus-N (mg kgminus1)FC 10082 plusmn 403a 14582 plusmn 352a 5638 plusmn 668b 2694 plusmn 418aDC 10844 plusmn 339a 1980 plusmn 144b 4611 plusmn 129b 3877 plusmn 515aFB 9824 plusmn 686a 15594 plusmn 1238a 7694 plusmn 249a 3726 plusmn 012aDB 10475 plusmn 531a 2554 plusmn 080b 4113 plusmn 490b 3919 plusmn 645a
Soil NO4
+-N (mg kgminus1)FC 214 plusmn 028a 198 plusmn 041ab 138 plusmn 019a 046 plusmn 008aDC 214 plusmn 021a 107 plusmn 013b 096 plusmn 001a 036 plusmn 008aFB 217 plusmn 005a 229 plusmn 016a 124 plusmn 024a 034 plusmn 005aDB 204 plusmn 011a 129 plusmn 006b 101 plusmn 012a 057 plusmn 016a
Table 3 Effects of different irrigationmethods and fertilization regimes on cotton yield and water use efficiency Values are means plusmn standarddeviation of three replicates Different small letters in the same column refer to significant difference between treatments at 119875 lt 005 level
FC DC FB DBCotton yield (Mg haminus1) 176 plusmn 016a 202 plusmn 010a 194 plusmn 017a 211 plusmn 014aWater use efficiency (kgmminus3) 029 plusmn 003b 045 plusmn 002a 032 plusmn 003b 047 plusmn 003a
8 The Scientific World Journal
Table 4 Effects of different irrigation methods and fertilizationregimes on accumulated N2O and CH4 emissions during cottongrowing season Values are means plusmn standard deviation of threereplicates Different small letters in the same column refer tosignificant difference between treatments at 119875 lt 005 level
N2O (kg haminus1) CH4 (kg haminus1)
FC 171 plusmn 013a minus292 plusmn 096abDC 109 plusmn 011b minus887 plusmn 185bFB 121 plusmn 007b 539 plusmn 491aDB 104 plusmn 006b minus684 plusmn 107b
coordinate the mineral N availability and plant uptake Thiswould reduce the amount of N available for denitrificationand lost as N
2O [18] On the other hand decreases in
emissions of N2O in soil amended with biochar might be
attributed to improved aeration and porosity for its developedmicrostructure which might lead to lower denitrificationrates and alter the N
2O-to-N
2ratio during denitrification
[16]The present study indicated that the arid cotton fields
under FC DC and DB were the sinks of CH4 while FB was
the source of CH4 This was consistent with the results of
previous studies with different irrigation methods conductedin upland field [39ndash41] However drip irrigation was asource of CH
4in the study in cotton field [22] which was
inconsistent with the present results This might be relatedto the different rate of irrigation and fertilization Uplandfields are normally net sinks for CH
4 since the consumption
exceeds the production in CH4[42] The dry soil in upland
field limited the CH4emission however it did have a
possibility to become a source after rainfall within severaldays orweeks [43 44] Comparing theCH
4emission between
DC and FC it was shown that DC increased the uptakeof CH
4for the relative lower soil moisture in most of the
time during cotton growing season (Figure 2(a)) The mainfactor affectingCH
4uptake in summerwas soilmoisture [45]
which plays a critical role inCH4consumption [46] Decrease
in soil moisture enhanced CH4oxidation through improving
CH4diffusion from atmosphere into soil pore spaces [47] and
through gas diffusivity to control microbial oxidation whichchanges inversely with soil moisture [48 49]
In our study the addition of biochar increased CH4
emissions by 2846 higher with FB than that with FC whilethe uptake of CH
4with DB was 229 lower than that with
DC The result was in good agreement with previous studythat biochar addition promoted CH
4emissions of the upland
soil [17] However other studies had reported that biocharamendment reduces CH
4emissions as compared with the
control [18 19] The inconsistence might be attributed to thesoil type agricultural management and biochar type On onehand the addition of biochar increased the substrate sup-ply and created a favorable environment for methanogenicactivity On the other hand the CH
4emission from acid
soil was usually much lower than that from neutral soil[50] Biochar addition could increase soil PH which was abenefit for methanogenic bacteria Furthermore increasedsoil aeration due to increased porosity could increase CH
4
diffusion Biochar might play a more important role underpaddy fields compared with straw returning directly whichwould increase CH
4emission obviously [51]
There was significant difference between drip irrigationtreatments and furrow irrigation treatments in the total GWPof N2O and CH
4emissions (119875 lt 001) while fertilization
regimes showed little effect (Figure 6) The average yield-scaledGWPwas 801 and 722 lowerwithDCandDB thanthat with FC indicating that drip irrigation couldmitigate theyield-scaled GHG emissions from cotton field In previousstudies cotton yield was higher with drip irrigation thanthat with furrow irrigation [52] which agreed with ourstudy Although the difference of cotton yield between fourtreatments was insignificant WUE was significantly higherwith DC and DB than that with FC by 538 and 602respectively (119875 lt 005) (Table 3) WUE represented inthis study (from 0263 kgmminus3 to 0527 kgmminus3) were lowerthan that from the studies in Turkey where it rangedfrom 0508 kgmminus3 to 0648 kgmminus3 or from 076 kgmminus3 to146 kgmminus3 [52 53]The variance inWUE in different ecositescould be related to climate plant number varietal differencesand irrigation amount [54] It indicated that drip irrigationsignificantly increased WUE of cotton plants in relation tofurrow irrigation The relative higher WUE with DC and DBwas related to improved fertilizer efficiency and depressedleaching potential in drip irrigation system [55]
5 Conclusions
Irrigation methods significantly affected the GHG emissionsfrom cotton field in arid northwestern China Biochar addi-tion increased CH
4emissions and decreased N
2O emissions
The water supply and N fertilizer dressing method played akey role in regulating gas emissions Drip irrigation treat-ments (DC and DB) remarkably reduced GHG emissionscompared with furrow irrigation treatments (FC and FB) Inaddition drip irrigation treatments (DC and DB) had higheryield and WUE compared to furrow irrigation treatments(FC and FB) Thus mulched-drip irrigation with conven-tional fertilization or conventional fertilization + biocharshould be a better approach to increase cotton yield withdepressed GHG emissions in arid northwestern China
Abbreviations
GHG Greenhouse gasGWP Global warming potentialWUE Water use efficiency
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgment
This work was financially supported by the opened subjectof Xinjiang Key Laboratory of Water Cycle and Utilization inArid Zone (Grant no XJYS0907-2010-03)
The Scientific World Journal 9
References
[1] IPCC Climate Change 2007 The Physical Science Basis Cam-bridge University Press Cambridge UK 2007
[2] A F Bouwman L J M Boumans and N H Baffes GlobalEstimates of Gaseous Emissions of NH
3 NO and N
2O from
Agricultural Land Food and Agriculture Organisation RomeItaly 2001
[3] FAOSTAT 2002 httpfaostatfaoorg[4] C Liu X Zheng Z Zhou et al ldquoNitrous oxide and nitric oxide
emissions from an irrigated cotton field in Northern ChinardquoPlant and Soil vol 332 no 1-2 pp 123ndash134 2010
[5] TMahmood RAli J Iqbal andURobab ldquoNitrous oxide emis-sion from an irrigated cotton field under semiarid subtropicalconditionsrdquo Biology and Fertility of Soils vol 44 no 5 pp 773ndash781 2008
[6] C Scheer R Wassmann K Kienzler N Ibragimov andR Eschanov ldquoNitrous oxide emissions from fertilized irri-gated cotton (Gossypium hirsutum L) in the Aral Sea BasinUzbekistan influence of nitrogen applications and irrigationpracticesrdquo Soil Biology and Biochemistry vol 40 no 2 pp 290ndash301 2008
[7] J Li J Zhang and L Ren ldquoWater and nitrogen distributionas affected by fertigation of ammonium nitrate from a pointsourcerdquo Irrigation Science vol 22 no 1 pp 19ndash30 2003
[8] C M Kallenbach D E Rolston and W R Horwath ldquoCovercropping affects soil N
2O and CO
2emissions differently
depending on type of irrigationrdquo Agriculture Ecosystems andEnvironment vol 137 no 3-4 pp 251ndash260 2010
[9] L Sanchez-Martın A Arce A Benito L Garcia-Torres andA Vallejo ldquoInfluence of drip and furrow irrigation systems onnitrogen oxide emissions from a horticultural croprdquo Soil Biologyand Biochemistry vol 40 no 7 pp 1698ndash1706 2008
[10] L Sanchez-Martın A Meijide L Garcia-Torres and A VallejoldquoCombination of drip irrigation and organic fertilizer formitigating emissions of nitrogen oxides in semiarid climaterdquoAgriculture Ecosystems and Environment vol 137 no 1-2 pp99ndash107 2010
[11] J Lehmann ldquoBio-energy in the blackrdquo Frontiers in Ecology andthe Environment vol 5 no 7 pp 381ndash387 2007
[12] M Fowles ldquoBlack carbon sequestration as an alternative tobioenergyrdquo Biomass and Bioenergy vol 31 no 6 pp 426ndash4322007
[13] M Rondon J A Ramirez and J Lehmann ldquoCharcoal additionsreduce net emissions of greenhouse gases to the atmosphererdquo inProceedings of the 3rd USDA Symposium on Greenhouse Gasesand Carbon Sequestration p 208 Baltimore Md USA March2005
[14] A Aguilar-Chavez M Dıaz-Rojas M del Rosario Cardenas-Aquino L Dendooven and M Luna-Guido ldquoGreenhouse gasemissions from a wastewater sludge-amended soil cultivatedwith wheat (Triticum spp L) as affected by different applicationrates of charcoalrdquo Soil Biology and Biochemistry vol 52 pp 90ndash95 2012
[15] S Castaldi M Riondino S Baronti et al ldquoImpact of biocharapplication to a Mediterranean wheat crop on soil microbialactivity and greenhouse gas fluxesrdquo Chemosphere vol 85 no9 pp 1464ndash1471 2011
[16] B P Singh B J Hatton B Singh A L Cowie and A KathurialdquoInfluence of biochars on nitrous oxide emission and nitrogenleaching from two contrasting soilsrdquo Journal of EnvironmentalQuality vol 39 no 4 pp 1224ndash1235 2010
[17] J Wang X Pan Y Liu X Zhang and Z Xiong ldquoEffects ofbiochar amendment in two soils on greenhouse gas emissionsand crop productionrdquo Plant and Soil vol 360 no 1-2 pp 287ndash298 2012
[18] K Karhu T Mattila I Bergstrom and K Regina ldquoBiocharaddition to agricultural soil increased CH
4uptake and water
holding capacitymdashresults from a short-term pilot field studyrdquoAgriculture Ecosystems and Environment vol 140 no 1-2 pp309ndash313 2011
[19] C Scheer P R Grace D W Rowlings S Kimber and L vanZwieten ldquoEffect of biochar amendment on the soil-atmosphereexchange of greenhouse gases from an intensive subtropicalpasture in northernNew SouthWales AustraliardquoPlant and Soilvol 345 no 1 pp 47ndash58 2011
[20] Z Li R Zhang X Wang J Wang C Zhang and C TianldquoCarbon dioxide fluxes and concentrations in a cotton fieldin northwestern China effects of plastic mulching and dripirrigationrdquo Pedosphere vol 21 no 2 pp 178ndash185 2011
[21] Q Zhang L Yang J Wang H Luo Y Zhang and WZhang ldquoEffects of different irrigation methods and fertilizationmeasures on soil respiration and its component contribution incotton field in arid regionrdquo Scientia Agricultura Sinica vol 25no 12 pp 2420ndash2430 2012 (Chinese)
[22] Z Li R Zhang X Wang F Chen D Lai and C Tian ldquoEffectsof plastic film mulching with drip irrigation on N
2O and CH
4
emissions fromcotton fields in arid landrdquo Journal of AgriculturalScience 2013
[23] FAOIAEA Measurement of Methane and Nitrous Oxide Emis-sion from Agriculture A Joint Undertakong by the Food andAgriculture Organization of United Nations and InternationalAtomic Energy Agency International Atomic Energy AgencyVienna Austria 1992
[24] Y Huang J Jiang L Zong Q Zhou R L Sass and F MFisher ldquoInfluence of planting density and precipitation on N
2O
emission from a winter wheat fieldrdquo Environmental Science vol22 no 6 pp 20ndash23 2001 (Chinese)
[25] G C Topp J L Davis and A P Annan ldquoElectromagneticdetermination of soil water content measurements in coaxialtransmission linesrdquoWater Resources Research vol 16 no 3 pp574ndash582 1980
[26] R Lu Soil Agricultural Chemistry Analytical Method ChinaAgricultural Science and Technology Press Beijing China2000
[27] L Zhou F Li S Jin and Y Song ldquoHow two ridges andthe furrow mulched with plastic film affect soil water soiltemperature and yield of maize on the semiarid Loess Plateauof Chinardquo Field Crops Research vol 113 no 1 pp 41ndash47 2009
[28] J Clemens M P Schillinger H Goldbach and B HuweldquoSpatial variability of N
2O emissions and soil parameters of an
arable silt loammdasha field studyrdquo Biology and Fertility of Soils vol28 no 4 pp 403ndash406 1999
[29] K InubushiM A Barahona andK Yamakawa ldquoEffects of saltsand moisture content on N
2O emission and nitrogen dynamics
in Yellow soil and Andosol in model experimentsrdquo Biology andFertility of Soils vol 29 no 4 pp 401ndash407 1999
[30] B J Joslashrgensen and R N Joslashrgensen ldquoField-scale and laboratorystudy of factors affecting N
2O emissions from a rye stubble field
on sandy loam soilrdquo Biology and Fertility of Soils vol 25 no 4pp 366ndash371 1997
[31] A R Mosier and Z Zhu ldquoChanges in patterns of fertilizernitrogen use in Asia and its consequences for N
2O emissions
10 The Scientific World Journal
from agricultural systemsrdquo Nutrient Cycling in Agroecosystemsvol 57 no 1 pp 107ndash117 2000
[32] R Ruser H Flessa R Schilling F Beese and J C MunchldquoEffect of crop-specific field management and N fertilizationon N2O emissions from a fine-loamy soilrdquo Nutrient Cycling in
Agroecosystems vol 59 no 2 pp 177ndash191 2001[33] C Song and J Zhang ldquoEffects of soil moisture temperature
and nitrogen fertilization on soil respiration and nitrous oxideemission duringmaize growth period in northeast ChinardquoActaAgriculturae Scandinavica B Soil and Plant Science vol 59 no2 pp 97ndash106 2009
[34] D M Linn and J W Doran ldquoEffect of water-filled pore spaceon carbon dioxide and nitrous oxide production in tilled andnontilled soilsrdquo Soil Science Society of America Journal vol 48no 6 pp 1267ndash1272 1984
[35] X J Liu A R Mosier A D Halvorson C A Reule andF S Zhang ldquoDinitrogen and N
2O emissions in arable soils
effect of tillage N source and soil moisturerdquo Soil Biology andBiochemistry vol 39 no 9 pp 2362ndash2370 2007
[36] L Sanchez-Martın A Vallejo J Dick and U M Skiba ldquoTheinfluence of soluble carbon and fertilizer nitrogen on nitricoxide and nitrous oxide emissions from two contrasting agri-cultural soilsrdquo Soil Biology and Biochemistry vol 40 no 1 pp142ndash151 2008
[37] Z Mu S D Kimura Y Toma and R Hatano ldquoNitrous oxidefluxes from upland soils in central Hokkaido Japanrdquo Journal ofEnvironmental Sciences vol 20 no 11 pp 1312ndash1322 2008
[38] B Liang J Lehmann D Solomon et al ldquoBlack carbon increasescation exchange capacity in soilsrdquo Soil Science Society of AmericaJournal vol 70 no 5 pp 1719ndash1730 2006
[39] P Boeckx and O Van Cleemput ldquoEstimates of N2O and CH
4
fluxes from agricultural lands in various regions in EuroperdquoNutrient Cycling in Agroecosystems vol 60 no 1ndash3 pp 35ndash472001
[40] J A MacDonald U Skiba L J Sheppard et al ldquoThe effectof nitrogen deposition and seasonal variability on methaneoxidation and nitrous oxide emission rates in an upland spruceplantation andmoorlandrdquoAtmospheric Environment vol 31 no22 pp 3693ndash3706 1997
[41] S C Whalen ldquoInfluence of N and non-N salts on atmosphericmethane oxidation by upland boreal forest and tundra soilsrdquoBiology and Fertility of Soils vol 31 no 3-4 pp 279ndash287 2000
[42] J P Megonigal and A B Guenther ldquoMethane emissions fromupland forest soils and vegetationrdquo Tree Physiology vol 28 no4 pp 491ndash498 2008
[43] E A Davidson F Y Ishida and D C Nepstad ldquoEffects ofan experimental drought on soil emissions of carbon dioxidemethane nitrous oxide and nitric oxide in a moist tropicalforestrdquo Global Change Biology vol 10 no 5 pp 718ndash730 2004
[44] F LWang and J R Bettany ldquoMethane emission fromCanadianprairie and forest soils under short term flooding conditionsrdquoNutrient Cycling in Agroecosystems vol 49 no 1ndash3 pp 197ndash2021997
[45] R BrummeandWBorken ldquoSite variation inmethane oxidationas affected by atmospheric deposition and type of temperateforest ecosystemrdquo Global Biogeochemical Cycles vol 13 no 2pp 493ndash501 1999
[46] A P S Adamsen and G M King ldquoMethane consumption intemperate and subarctic forest soils rates vertical zonation andresponses to water and nitrogenrdquo Applied and EnvironmentalMicrobiology vol 59 no 2 pp 485ndash490 1993
[47] M S Castro P A Steudler J M Melillo J D Aber and R DBowden ldquoFactors controlling atmospheric methane consump-tion by temperate forest soilsrdquoGlobal Biogeochemical Cycles vol9 no 1 pp 1ndash10 1995
[48] B C Ball K A Smith L Klemedtsson et al ldquoThe influence ofsoil gas transport properties onmethane oxidation in a selectionof northern European soilsrdquo Journal of Geophysical Research Dvol 102 no 19 pp 23309ndash23317 1997
[49] K A Smith T Ball F Conen K E Dobbie J Masshederand A Rey ldquoExchange of greenhouse gases between soil andatmosphere interactions of soil physical factors and biologicalprocessesrdquo European Journal of Soil Science vol 54 no 4 pp779ndash791 2003
[50] H Feng G Cheng and L An ldquoMicrobial-mediated methanecycle in soils and global change a reviewrdquo Journal of Glaciologyand Geocryology vol 26 no 4 pp 411ndash419 2006 (Chinese)
[51] Y YanDWang and J Zheng ldquoAdvances in effects of biochar onthe soil N
2O and CH
4emissionsrdquo Chinese Agricultural Science
Bulletin vol 29 no 8 pp 140ndash146 2013 (Chinese)[52] OCetin andL Bilgel ldquoEffects of different irrigationmethods on
shedding and yield of cottonrdquo Agricultural Water Managementvol 54 no 1 pp 1ndash15 2002
[53] NDagdelenaH Basalb E Yılmaza T Gurbuza and S AkcayaldquoDifferent drip irrigation regimes affect cotton yield water useefficiency and fiber quality in western Turkeyrdquo AgriculturalWater Management vol 96 no 1 pp 110ndash120 2009
[54] N Ibragimov S R Evett Y Esanbekov B S Kamilov LMirzaev and J P A Lamers ldquoWater use efficiency of irrigatedcotton in Uzbekistan under drip and furrow irrigationrdquo Agri-cultural Water Management vol 90 no 1-2 pp 112ndash120 2007
[55] C R Camp P J Bauer and P G Hunt ldquoSubsurface dripirrigation lateral spacing and management for cotton in thesoutheastern Coastal plainrdquo Transactions of the American Soci-ety of Agricultural Engineers vol 40 no 4 pp 993ndash999 1997
Submit your manuscripts athttpwwwhindawicom
Nutrition and Metabolism
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Food ScienceInternational Journal of
Agronomy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom
Applied ampEnvironmentalSoil Science
Volume 2014
AgricultureAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
PsycheHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BiodiversityInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Plant GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biotechnology Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Forestry ResearchInternational Journal of
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Journal of BotanyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
EcologyInternational Journal of
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Veterinary Medicine International
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Cell BiologyInternational Journal of
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Evolutionary BiologyInternational Journal of
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The Scientific World Journal 3
Table 1 The applications of irrigation and topdressing during the cotton growth period
Irrigation date Drip irrigation treatments Furrow irrigation treatmentsVolume
(m3sdothmminus2) Urea (kgsdothmminus2) Potassium dihydrogen
phosphate (kgsdothmminus2)Volume
(m3sdothmminus2) Urea (kgsdothmminus2) Potassium dihydrogen
phosphate (kgsdothmminus2)610-611 225 30 15 1050 150624-625 300 30 15 1500 300 6073 300 3079-710 375 60 1500 105 30717 450 75723-724 450 75 120081 450 6085-86 450 60 750813 375 45 15821 375 45 15827 300 30 1593 225 15 15910 225
Sampling area
Drip irrigation
tape
Drip irrigation
tape
Plastic film
10 cm
30 cm 30 cm 30 cm 30 cm60 cm 60 cm 60 cm
(a)
Sampling area
10 cm
30 cm 30 cm 30 cm 30 cm60 cm 60 cm 60 cm
(b)
Figure 1 Experimental layout in the cotton field for drip irrigation treatments (DC DB) (a) and furrow irrigation treatments (FC FB) (b)
4 The Scientific World Journal
CH4flux were calculated by the linear increase of the gas
concentration at each sampling time (0 10 20 and 30min)sample sets were rejected unless the correlation coefficient(R2) for the linear regression is greater than 09 (07 for smallflux rates) All flux rates were adjusted for air temperature airpressure and area and volume of the chamber [24] AverageGHG fluxes were calculated by triplicate plots Seasonalaccumulation amounts of GHG emissions were calculated bythe emissions between every two adjacent intervals of themeasurements
24 Soil Temperature Moisture and Mineral N ContentSoil temperature and soil moisture were measured at fourdifferent points near the area covered by the chamber Soiltemperature was taken at 5 cm depth Soil moisture wasdetermined using a TDR (time domain reflectometer) [25]
Surface soil samples (0ndash20 cm) at the experiment plotsclose to the chamber covered area were collected for theanalysis of soil mineral N (ammonium and nitrate) contentsat the same day as the gas sampling during the cotton growthseason Fresh soil samples were extracted with 001M CaCl
2
in a 1 10 ratio of soil to extractant The concentrations ofammonium and nitrate in the extract were analyzed usingcontinuous flow analytical system [26] Cotton yield wasrecorded at cotton harvest
25 Statistical Analyses Differences in seasonal N2O and
CH4emissions soil temperature soil Nmineral contents and
cotton yield as affected by irrigationmethods and fertilizationregimes were examined by using a two-way analysis ofvariance (ANOVA) The statistical analysis was carried outusing SPSS 200 (IBM SPSS Statistics Chicago IL USA)
3 Results
31 Soil Characteristics CottonYield andWaterUse EfficiencyThe soil moisture under FC and FB was significantly higherthan that under DC and DB on June 30 July 14 and July 28while on other days the soil moisture with FC and FB wasclose to that with DC and DB (Figure 2(a)) The soil tem-peratures during cotton growing season were significantlyhigher with DC and DB than with FC and FB during thebud stage (119875 lt 005) (Table 2) As compared with FC DCshowed significantly lower soil temperature during floweringand boll-forming stage (119875 lt 005) (Table 2) Howeverfertilization regimes had no effect on soil temperature Thesoil NO
3
minus-N contents were significantly higher with FC andFB than with DC and DB during the bud stage and thatwith FB was significantly higher than those with FC DC andDB during the flowering and boll-forming stage (119875 lt 005)(Table 2 Figure 3(b)) whichwas caused by the topdressing ofN fertilizer in furrow irrigation plots This topdressing eventalso led to a peak in soil NH
4
+-N contents with FC and FB onJune 23 and June 30 (Figure 3(c))
Although there was no significant difference betweenthe cotton yield among these four treatments the wateruse efficiency (WUE) calculated on cotton yield per unitirrigation volume was significantly higher with DC and DB
than that with FCby 538 and 602 respectively (119875 lt 005)(Table 3)
32 N2O Fluxes The N
2O flux rates with FC varied from
70 120583gmminus2 hminus1 to 3209 120583gmminus2 hminus1 during the cotton grow-ing season with two flux peaks on June 30 and July 21(Figure 4(a)) As compared with FC the N
2O flux rates of
FB were relatively stable and lower Under DC the N2O
flux rates were relatively lower among the sampling datescomparing to FC except a flux peak on August 9 On mostdays the N
2O flux rates with DB were close to that with
DC (Figure 4(a)) The accumulated N2O emissions during
the cotton growing season were significantly lower with FBDC and DB than that with FC by 288 361 and 376respectively (119875 lt 005) (Table 4) At different growth stagesthe highest N
2O flux rate under FC DC and DB appeared
at the flowering and boll-forming stage while FB appearedat the bud stage (Figure 4(b)) The N
2O flux rate with FC
performed differently with other three treatments at theflowering and boll-forming stage and the bud stage (119875 lt005) No significant difference was observed between DCand DB during the whole period
33 CH4Fluxes The CH
4flux rates under FC DC and
DB were below zero on most sampling days indicating thatcotton fields were the sink of CH
4except under FB for most
of the time of the cotton growing season (Figure 5(a)) TheCH4flux rates were similar under the four treatments in
May and June but diverged after June The highest uptake ofCH4appeared at the flowering and boll-forming stage under
FC and DB while it appeared at the bud stage under DC(Figure 5(b)) The accumulated CH
4emissions during the
cotton growing season were significantly lower with DC andDB than that with FB by 2645 and 2267 respectively(119875 lt 005) (Table 4) Although the accumulated CH
4
emission under FC was 1542 lower than that with FB therewas little difference between the two treatments
34 Yield-Scaled GWP The total GWP of N2O and CH
4
emissions during cotton growing season was 10289 1462343509 and 49649 under treatments of DC DB FC and FBrespectively (Figure 6(a)) Cotton fields under DC DB andFC were all sinks for CH
4 which reduced the contribution
of N2O emission to the overall GWP by 683 539
and 144 respectively The yield-scaled GWP calculated byGWP per unit cotton yield with FC and FB were significantlyhigher than those with DC and DB (119875 lt 001) (Figure 6(b))As compared with FC DC and DB were 801 and 722lower in yield-scaled GWP respectively Irrigation methodsshowed extremely significant effect on the total GWP andyield-scaled GWP (119875 lt 001) while fertilization regimes hadno effect on both
4 Discussion
In the present study it was observed that the soil temperatureduring cotton growing season was higher with DC and DBthan with FC and FB in most of the time during cotton
The Scientific World Journal 5
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 10
10
20
30
40
FCDCFB
DB
0
30
60
90
120
Prec
ipita
tion
(mm
)
Precipitation
Volu
met
ric so
il w
ater
cont
ent (
)
(a)
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 10
500
1000
1500
2000
FC FBDC DB
Irrig
atio
n vo
lum
e (m
3ha
minus1)
(b)
Figure 2 Effects of different irrigation methods and fertilization regimes on soil moisture precipitation and volume of irrigation waterduring cotton growing season
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 110
15
20
25
30
35
FCDC
FBDB
Soil
tem
pera
ture
(∘C)
(a)
FCDC
FBDB
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 10
50
100
150
200
250
NO
3ndashN
(mg k
gminus1)
(b)
FCDC
FBDB
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 10
2
4
6
NH
3ndashN
(mg k
gminus1)
(c)
Figure 3 Effects of different irrigation methods and fertilization regimes on soil temperature and mineral N contents during cotton growingseason
growing season for the plastic film mulching A similarresult was found in the previous study for different irrigationmethods in maize field in China [27]The plastic film usuallyprevents the evaporation of soil moisture [22] However thedifference of the soil moisture between four treatments wasprimarily attributed to the water supply regimes (Figure 2)The plastic film showed little effect on maintenance of soilmoisture in the present study Biochar can efficiently retain
soil moisture due to its special physical structure [18] whichwas consistent with our results under DC and DB
The emissions of N2O and CH
4from cotton field were
investigated under different irrigation methods and fertil-ization regimes in an arid area of northwestern China Theaccumulated N
2O emissions during cotton growth season in
this study were lower than that from semiarid cotton fieldin northern China [4] and arid cotton fields in Uzbekistan
6 The Scientific World Journal
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 10
100
200
300
400
FCDC
FBDB
N2O
(120583g m
minus2
hminus1)
(a)
Seedling stage Bud stage Flowering and boll-forming stage
Boll opening 0
30
60
90
120
FCDC
FBDB
stage
N2O
(120583g m
minus2
hminus1)
(b)
Figure 4 Effects of different irrigation methods and fertilization regimes on N2O flux rates during cotton growing season
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 1
0
5
10
CH4
(mg m
minus2
hminus1)
minus5
minus10
FCDC
FBDB
(a)
Seedling stage Bud stage Flowering and boll-forming stage
Boll opening
00
15
30
minus15
minus30
stage
CH4
(mg m
minus2
hminus1)
FCDC
FBDB
(b)
Figure 5 Effects of different irrigation methods and fertilization regimes on CH4flux rates during cotton growing season
[6] but higher than the N2O emissions from semiarid cotton
field in Pakistan [5] The variance in N2O emission among
different ecosites might be attributed to the difference in Nfertilizer application rate irrigation climate factors and soilproperties [28ndash33] Here lower level of N
2O emission from
cotton field was found under FB DC and DB in relation toFC with a high N fertilizer application rate (300 kgNhaminus1)(Table 4)The relatively lowerN
2Oemission from cotton field
under drip irrigation treatments was mainly attributed to thewater supply regime and N fertilizer dressing method (so-called fertigation) in drip irrigation system which favoreddecrease in N
2O emission In detail the soil moisture was
lower in cotton field with drip irrigation treatments than thatwith FC during the bud stage which was the main fertiliza-tion time of FC Previous studies reported that soilmoisture isa key factor in regulation of N
2O emission from agricultural
soil For instance theN2Oemissionwas enhanced alongwith
increased soil moisture in a given range due to the improveddenitrification [34ndash36] Therefore the relatively lower soilmoisture in cotton field withDC andDB during the bud stagecould reduce the N
2O emission more effectively than that
with FC Furthermore the decreased N fertilizer was directly
fertigated to the rhizosphere of cotton plants in drip irrigationtreatments with more times but less application rate pertimeThis N fertilizer dressing method could also improve Nuptake of cotton plant but decrease the soil inorganic N pool(NO3
minus-N and NH4
+-N) (Table 2) and hence reduce N sourceforN2Oemission whichwas significantly correlatedwith soil
N [37] However the observed reduction in N2O emission
caused by drip irrigationwas less than that in previous studiesconducted in the melon and tomato fields [8ndash10] This mightbe related to higher N fertilizer application rate in this study(300 kgNhaminus1) suggesting that the mitigation effect of dripirrigation onN
2Omay be depressed with a higher N fertilizer
application rateAlthough FB and FC used the same irrigation system
FB showed lower N2O emission than FC for the addition of
biochar A similar result was found in wheat field [14 15]However the effect of biochar on N
2O emissions under DB
and DC was covered up by the effect of drip irrigationBiochar had been shown to efficiently retain NH
4
+ via cationexchange by its developed specific surface area and surfacenegative charge density [38] Then the retained N wouldbe slowly released for plant growth thus biochar could
The Scientific World Journal 7
FC DC FB DB
0
500
1000
1500G
WP
(kg
CO2
eqha
minus1)
minus500
CH4
N2O
(a) Overall GWP
FC DC FB DB0
100
200
300
400
500
Yiel
d-sc
aled
GW
P (k
gCO
2eq
haminus1)
(b) Yield-scaled GWP
Figure 6 Overall GWP of GHGs (a) and yield-scaled GWP (b) for different treatmentsThe error bar in (a) was the standard error of overallGWP of N
2O and CH
4emissions
Table 2 Effects of different irrigation methods and fertilization regimes on major soil characteristics Values are means plusmn standard deviationof three replicates Different small letters in the same column refer to significant difference between treatments at 119875 lt 005 level
Seedling stage Bud stage Flowering and boll-forming stage Boll opening stageSoil moisture ()
FC 1679 plusmn 037b 1863 plusmn 025a 2046 plusmn 104a 1600 plusmn 125bDC 1728 plusmn 005b 1224 plusmn 013c 1979 plusmn 100a 1881 plusmn 113aFB 1819 plusmn 035ab 1892 plusmn 035a 1952 plusmn 085a 1416 plusmn 150bDB 1965 plusmn 071a 1493 plusmn 069b 2311 plusmn 082a 1870 plusmn 156a
Soil temperature (∘C)FC 2401 plusmn 033a 2455 plusmn 012b 212 plusmn 012b 1853 plusmn 010aDC 2398 plusmn 012a 2629 plusmn 025a 2255 plusmn 015a 1829 plusmn 027aFB 2428 plusmn 019a 2441 plusmn 036b 2178 plusmn 037ab 1803 plusmn 037aDB 2392 plusmn 009a 2580 plusmn 037a 2211 plusmn 033ab 1800 plusmn 005a
Soil NO3
minus-N (mg kgminus1)FC 10082 plusmn 403a 14582 plusmn 352a 5638 plusmn 668b 2694 plusmn 418aDC 10844 plusmn 339a 1980 plusmn 144b 4611 plusmn 129b 3877 plusmn 515aFB 9824 plusmn 686a 15594 plusmn 1238a 7694 plusmn 249a 3726 plusmn 012aDB 10475 plusmn 531a 2554 plusmn 080b 4113 plusmn 490b 3919 plusmn 645a
Soil NO4
+-N (mg kgminus1)FC 214 plusmn 028a 198 plusmn 041ab 138 plusmn 019a 046 plusmn 008aDC 214 plusmn 021a 107 plusmn 013b 096 plusmn 001a 036 plusmn 008aFB 217 plusmn 005a 229 plusmn 016a 124 plusmn 024a 034 plusmn 005aDB 204 plusmn 011a 129 plusmn 006b 101 plusmn 012a 057 plusmn 016a
Table 3 Effects of different irrigationmethods and fertilization regimes on cotton yield and water use efficiency Values are means plusmn standarddeviation of three replicates Different small letters in the same column refer to significant difference between treatments at 119875 lt 005 level
FC DC FB DBCotton yield (Mg haminus1) 176 plusmn 016a 202 plusmn 010a 194 plusmn 017a 211 plusmn 014aWater use efficiency (kgmminus3) 029 plusmn 003b 045 plusmn 002a 032 plusmn 003b 047 plusmn 003a
8 The Scientific World Journal
Table 4 Effects of different irrigation methods and fertilizationregimes on accumulated N2O and CH4 emissions during cottongrowing season Values are means plusmn standard deviation of threereplicates Different small letters in the same column refer tosignificant difference between treatments at 119875 lt 005 level
N2O (kg haminus1) CH4 (kg haminus1)
FC 171 plusmn 013a minus292 plusmn 096abDC 109 plusmn 011b minus887 plusmn 185bFB 121 plusmn 007b 539 plusmn 491aDB 104 plusmn 006b minus684 plusmn 107b
coordinate the mineral N availability and plant uptake Thiswould reduce the amount of N available for denitrificationand lost as N
2O [18] On the other hand decreases in
emissions of N2O in soil amended with biochar might be
attributed to improved aeration and porosity for its developedmicrostructure which might lead to lower denitrificationrates and alter the N
2O-to-N
2ratio during denitrification
[16]The present study indicated that the arid cotton fields
under FC DC and DB were the sinks of CH4 while FB was
the source of CH4 This was consistent with the results of
previous studies with different irrigation methods conductedin upland field [39ndash41] However drip irrigation was asource of CH
4in the study in cotton field [22] which was
inconsistent with the present results This might be relatedto the different rate of irrigation and fertilization Uplandfields are normally net sinks for CH
4 since the consumption
exceeds the production in CH4[42] The dry soil in upland
field limited the CH4emission however it did have a
possibility to become a source after rainfall within severaldays orweeks [43 44] Comparing theCH
4emission between
DC and FC it was shown that DC increased the uptakeof CH
4for the relative lower soil moisture in most of the
time during cotton growing season (Figure 2(a)) The mainfactor affectingCH
4uptake in summerwas soilmoisture [45]
which plays a critical role inCH4consumption [46] Decrease
in soil moisture enhanced CH4oxidation through improving
CH4diffusion from atmosphere into soil pore spaces [47] and
through gas diffusivity to control microbial oxidation whichchanges inversely with soil moisture [48 49]
In our study the addition of biochar increased CH4
emissions by 2846 higher with FB than that with FC whilethe uptake of CH
4with DB was 229 lower than that with
DC The result was in good agreement with previous studythat biochar addition promoted CH
4emissions of the upland
soil [17] However other studies had reported that biocharamendment reduces CH
4emissions as compared with the
control [18 19] The inconsistence might be attributed to thesoil type agricultural management and biochar type On onehand the addition of biochar increased the substrate sup-ply and created a favorable environment for methanogenicactivity On the other hand the CH
4emission from acid
soil was usually much lower than that from neutral soil[50] Biochar addition could increase soil PH which was abenefit for methanogenic bacteria Furthermore increasedsoil aeration due to increased porosity could increase CH
4
diffusion Biochar might play a more important role underpaddy fields compared with straw returning directly whichwould increase CH
4emission obviously [51]
There was significant difference between drip irrigationtreatments and furrow irrigation treatments in the total GWPof N2O and CH
4emissions (119875 lt 001) while fertilization
regimes showed little effect (Figure 6) The average yield-scaledGWPwas 801 and 722 lowerwithDCandDB thanthat with FC indicating that drip irrigation couldmitigate theyield-scaled GHG emissions from cotton field In previousstudies cotton yield was higher with drip irrigation thanthat with furrow irrigation [52] which agreed with ourstudy Although the difference of cotton yield between fourtreatments was insignificant WUE was significantly higherwith DC and DB than that with FC by 538 and 602respectively (119875 lt 005) (Table 3) WUE represented inthis study (from 0263 kgmminus3 to 0527 kgmminus3) were lowerthan that from the studies in Turkey where it rangedfrom 0508 kgmminus3 to 0648 kgmminus3 or from 076 kgmminus3 to146 kgmminus3 [52 53]The variance inWUE in different ecositescould be related to climate plant number varietal differencesand irrigation amount [54] It indicated that drip irrigationsignificantly increased WUE of cotton plants in relation tofurrow irrigation The relative higher WUE with DC and DBwas related to improved fertilizer efficiency and depressedleaching potential in drip irrigation system [55]
5 Conclusions
Irrigation methods significantly affected the GHG emissionsfrom cotton field in arid northwestern China Biochar addi-tion increased CH
4emissions and decreased N
2O emissions
The water supply and N fertilizer dressing method played akey role in regulating gas emissions Drip irrigation treat-ments (DC and DB) remarkably reduced GHG emissionscompared with furrow irrigation treatments (FC and FB) Inaddition drip irrigation treatments (DC and DB) had higheryield and WUE compared to furrow irrigation treatments(FC and FB) Thus mulched-drip irrigation with conven-tional fertilization or conventional fertilization + biocharshould be a better approach to increase cotton yield withdepressed GHG emissions in arid northwestern China
Abbreviations
GHG Greenhouse gasGWP Global warming potentialWUE Water use efficiency
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgment
This work was financially supported by the opened subjectof Xinjiang Key Laboratory of Water Cycle and Utilization inArid Zone (Grant no XJYS0907-2010-03)
The Scientific World Journal 9
References
[1] IPCC Climate Change 2007 The Physical Science Basis Cam-bridge University Press Cambridge UK 2007
[2] A F Bouwman L J M Boumans and N H Baffes GlobalEstimates of Gaseous Emissions of NH
3 NO and N
2O from
Agricultural Land Food and Agriculture Organisation RomeItaly 2001
[3] FAOSTAT 2002 httpfaostatfaoorg[4] C Liu X Zheng Z Zhou et al ldquoNitrous oxide and nitric oxide
emissions from an irrigated cotton field in Northern ChinardquoPlant and Soil vol 332 no 1-2 pp 123ndash134 2010
[5] TMahmood RAli J Iqbal andURobab ldquoNitrous oxide emis-sion from an irrigated cotton field under semiarid subtropicalconditionsrdquo Biology and Fertility of Soils vol 44 no 5 pp 773ndash781 2008
[6] C Scheer R Wassmann K Kienzler N Ibragimov andR Eschanov ldquoNitrous oxide emissions from fertilized irri-gated cotton (Gossypium hirsutum L) in the Aral Sea BasinUzbekistan influence of nitrogen applications and irrigationpracticesrdquo Soil Biology and Biochemistry vol 40 no 2 pp 290ndash301 2008
[7] J Li J Zhang and L Ren ldquoWater and nitrogen distributionas affected by fertigation of ammonium nitrate from a pointsourcerdquo Irrigation Science vol 22 no 1 pp 19ndash30 2003
[8] C M Kallenbach D E Rolston and W R Horwath ldquoCovercropping affects soil N
2O and CO
2emissions differently
depending on type of irrigationrdquo Agriculture Ecosystems andEnvironment vol 137 no 3-4 pp 251ndash260 2010
[9] L Sanchez-Martın A Arce A Benito L Garcia-Torres andA Vallejo ldquoInfluence of drip and furrow irrigation systems onnitrogen oxide emissions from a horticultural croprdquo Soil Biologyand Biochemistry vol 40 no 7 pp 1698ndash1706 2008
[10] L Sanchez-Martın A Meijide L Garcia-Torres and A VallejoldquoCombination of drip irrigation and organic fertilizer formitigating emissions of nitrogen oxides in semiarid climaterdquoAgriculture Ecosystems and Environment vol 137 no 1-2 pp99ndash107 2010
[11] J Lehmann ldquoBio-energy in the blackrdquo Frontiers in Ecology andthe Environment vol 5 no 7 pp 381ndash387 2007
[12] M Fowles ldquoBlack carbon sequestration as an alternative tobioenergyrdquo Biomass and Bioenergy vol 31 no 6 pp 426ndash4322007
[13] M Rondon J A Ramirez and J Lehmann ldquoCharcoal additionsreduce net emissions of greenhouse gases to the atmosphererdquo inProceedings of the 3rd USDA Symposium on Greenhouse Gasesand Carbon Sequestration p 208 Baltimore Md USA March2005
[14] A Aguilar-Chavez M Dıaz-Rojas M del Rosario Cardenas-Aquino L Dendooven and M Luna-Guido ldquoGreenhouse gasemissions from a wastewater sludge-amended soil cultivatedwith wheat (Triticum spp L) as affected by different applicationrates of charcoalrdquo Soil Biology and Biochemistry vol 52 pp 90ndash95 2012
[15] S Castaldi M Riondino S Baronti et al ldquoImpact of biocharapplication to a Mediterranean wheat crop on soil microbialactivity and greenhouse gas fluxesrdquo Chemosphere vol 85 no9 pp 1464ndash1471 2011
[16] B P Singh B J Hatton B Singh A L Cowie and A KathurialdquoInfluence of biochars on nitrous oxide emission and nitrogenleaching from two contrasting soilsrdquo Journal of EnvironmentalQuality vol 39 no 4 pp 1224ndash1235 2010
[17] J Wang X Pan Y Liu X Zhang and Z Xiong ldquoEffects ofbiochar amendment in two soils on greenhouse gas emissionsand crop productionrdquo Plant and Soil vol 360 no 1-2 pp 287ndash298 2012
[18] K Karhu T Mattila I Bergstrom and K Regina ldquoBiocharaddition to agricultural soil increased CH
4uptake and water
holding capacitymdashresults from a short-term pilot field studyrdquoAgriculture Ecosystems and Environment vol 140 no 1-2 pp309ndash313 2011
[19] C Scheer P R Grace D W Rowlings S Kimber and L vanZwieten ldquoEffect of biochar amendment on the soil-atmosphereexchange of greenhouse gases from an intensive subtropicalpasture in northernNew SouthWales AustraliardquoPlant and Soilvol 345 no 1 pp 47ndash58 2011
[20] Z Li R Zhang X Wang J Wang C Zhang and C TianldquoCarbon dioxide fluxes and concentrations in a cotton fieldin northwestern China effects of plastic mulching and dripirrigationrdquo Pedosphere vol 21 no 2 pp 178ndash185 2011
[21] Q Zhang L Yang J Wang H Luo Y Zhang and WZhang ldquoEffects of different irrigation methods and fertilizationmeasures on soil respiration and its component contribution incotton field in arid regionrdquo Scientia Agricultura Sinica vol 25no 12 pp 2420ndash2430 2012 (Chinese)
[22] Z Li R Zhang X Wang F Chen D Lai and C Tian ldquoEffectsof plastic film mulching with drip irrigation on N
2O and CH
4
emissions fromcotton fields in arid landrdquo Journal of AgriculturalScience 2013
[23] FAOIAEA Measurement of Methane and Nitrous Oxide Emis-sion from Agriculture A Joint Undertakong by the Food andAgriculture Organization of United Nations and InternationalAtomic Energy Agency International Atomic Energy AgencyVienna Austria 1992
[24] Y Huang J Jiang L Zong Q Zhou R L Sass and F MFisher ldquoInfluence of planting density and precipitation on N
2O
emission from a winter wheat fieldrdquo Environmental Science vol22 no 6 pp 20ndash23 2001 (Chinese)
[25] G C Topp J L Davis and A P Annan ldquoElectromagneticdetermination of soil water content measurements in coaxialtransmission linesrdquoWater Resources Research vol 16 no 3 pp574ndash582 1980
[26] R Lu Soil Agricultural Chemistry Analytical Method ChinaAgricultural Science and Technology Press Beijing China2000
[27] L Zhou F Li S Jin and Y Song ldquoHow two ridges andthe furrow mulched with plastic film affect soil water soiltemperature and yield of maize on the semiarid Loess Plateauof Chinardquo Field Crops Research vol 113 no 1 pp 41ndash47 2009
[28] J Clemens M P Schillinger H Goldbach and B HuweldquoSpatial variability of N
2O emissions and soil parameters of an
arable silt loammdasha field studyrdquo Biology and Fertility of Soils vol28 no 4 pp 403ndash406 1999
[29] K InubushiM A Barahona andK Yamakawa ldquoEffects of saltsand moisture content on N
2O emission and nitrogen dynamics
in Yellow soil and Andosol in model experimentsrdquo Biology andFertility of Soils vol 29 no 4 pp 401ndash407 1999
[30] B J Joslashrgensen and R N Joslashrgensen ldquoField-scale and laboratorystudy of factors affecting N
2O emissions from a rye stubble field
on sandy loam soilrdquo Biology and Fertility of Soils vol 25 no 4pp 366ndash371 1997
[31] A R Mosier and Z Zhu ldquoChanges in patterns of fertilizernitrogen use in Asia and its consequences for N
2O emissions
10 The Scientific World Journal
from agricultural systemsrdquo Nutrient Cycling in Agroecosystemsvol 57 no 1 pp 107ndash117 2000
[32] R Ruser H Flessa R Schilling F Beese and J C MunchldquoEffect of crop-specific field management and N fertilizationon N2O emissions from a fine-loamy soilrdquo Nutrient Cycling in
Agroecosystems vol 59 no 2 pp 177ndash191 2001[33] C Song and J Zhang ldquoEffects of soil moisture temperature
and nitrogen fertilization on soil respiration and nitrous oxideemission duringmaize growth period in northeast ChinardquoActaAgriculturae Scandinavica B Soil and Plant Science vol 59 no2 pp 97ndash106 2009
[34] D M Linn and J W Doran ldquoEffect of water-filled pore spaceon carbon dioxide and nitrous oxide production in tilled andnontilled soilsrdquo Soil Science Society of America Journal vol 48no 6 pp 1267ndash1272 1984
[35] X J Liu A R Mosier A D Halvorson C A Reule andF S Zhang ldquoDinitrogen and N
2O emissions in arable soils
effect of tillage N source and soil moisturerdquo Soil Biology andBiochemistry vol 39 no 9 pp 2362ndash2370 2007
[36] L Sanchez-Martın A Vallejo J Dick and U M Skiba ldquoTheinfluence of soluble carbon and fertilizer nitrogen on nitricoxide and nitrous oxide emissions from two contrasting agri-cultural soilsrdquo Soil Biology and Biochemistry vol 40 no 1 pp142ndash151 2008
[37] Z Mu S D Kimura Y Toma and R Hatano ldquoNitrous oxidefluxes from upland soils in central Hokkaido Japanrdquo Journal ofEnvironmental Sciences vol 20 no 11 pp 1312ndash1322 2008
[38] B Liang J Lehmann D Solomon et al ldquoBlack carbon increasescation exchange capacity in soilsrdquo Soil Science Society of AmericaJournal vol 70 no 5 pp 1719ndash1730 2006
[39] P Boeckx and O Van Cleemput ldquoEstimates of N2O and CH
4
fluxes from agricultural lands in various regions in EuroperdquoNutrient Cycling in Agroecosystems vol 60 no 1ndash3 pp 35ndash472001
[40] J A MacDonald U Skiba L J Sheppard et al ldquoThe effectof nitrogen deposition and seasonal variability on methaneoxidation and nitrous oxide emission rates in an upland spruceplantation andmoorlandrdquoAtmospheric Environment vol 31 no22 pp 3693ndash3706 1997
[41] S C Whalen ldquoInfluence of N and non-N salts on atmosphericmethane oxidation by upland boreal forest and tundra soilsrdquoBiology and Fertility of Soils vol 31 no 3-4 pp 279ndash287 2000
[42] J P Megonigal and A B Guenther ldquoMethane emissions fromupland forest soils and vegetationrdquo Tree Physiology vol 28 no4 pp 491ndash498 2008
[43] E A Davidson F Y Ishida and D C Nepstad ldquoEffects ofan experimental drought on soil emissions of carbon dioxidemethane nitrous oxide and nitric oxide in a moist tropicalforestrdquo Global Change Biology vol 10 no 5 pp 718ndash730 2004
[44] F LWang and J R Bettany ldquoMethane emission fromCanadianprairie and forest soils under short term flooding conditionsrdquoNutrient Cycling in Agroecosystems vol 49 no 1ndash3 pp 197ndash2021997
[45] R BrummeandWBorken ldquoSite variation inmethane oxidationas affected by atmospheric deposition and type of temperateforest ecosystemrdquo Global Biogeochemical Cycles vol 13 no 2pp 493ndash501 1999
[46] A P S Adamsen and G M King ldquoMethane consumption intemperate and subarctic forest soils rates vertical zonation andresponses to water and nitrogenrdquo Applied and EnvironmentalMicrobiology vol 59 no 2 pp 485ndash490 1993
[47] M S Castro P A Steudler J M Melillo J D Aber and R DBowden ldquoFactors controlling atmospheric methane consump-tion by temperate forest soilsrdquoGlobal Biogeochemical Cycles vol9 no 1 pp 1ndash10 1995
[48] B C Ball K A Smith L Klemedtsson et al ldquoThe influence ofsoil gas transport properties onmethane oxidation in a selectionof northern European soilsrdquo Journal of Geophysical Research Dvol 102 no 19 pp 23309ndash23317 1997
[49] K A Smith T Ball F Conen K E Dobbie J Masshederand A Rey ldquoExchange of greenhouse gases between soil andatmosphere interactions of soil physical factors and biologicalprocessesrdquo European Journal of Soil Science vol 54 no 4 pp779ndash791 2003
[50] H Feng G Cheng and L An ldquoMicrobial-mediated methanecycle in soils and global change a reviewrdquo Journal of Glaciologyand Geocryology vol 26 no 4 pp 411ndash419 2006 (Chinese)
[51] Y YanDWang and J Zheng ldquoAdvances in effects of biochar onthe soil N
2O and CH
4emissionsrdquo Chinese Agricultural Science
Bulletin vol 29 no 8 pp 140ndash146 2013 (Chinese)[52] OCetin andL Bilgel ldquoEffects of different irrigationmethods on
shedding and yield of cottonrdquo Agricultural Water Managementvol 54 no 1 pp 1ndash15 2002
[53] NDagdelenaH Basalb E Yılmaza T Gurbuza and S AkcayaldquoDifferent drip irrigation regimes affect cotton yield water useefficiency and fiber quality in western Turkeyrdquo AgriculturalWater Management vol 96 no 1 pp 110ndash120 2009
[54] N Ibragimov S R Evett Y Esanbekov B S Kamilov LMirzaev and J P A Lamers ldquoWater use efficiency of irrigatedcotton in Uzbekistan under drip and furrow irrigationrdquo Agri-cultural Water Management vol 90 no 1-2 pp 112ndash120 2007
[55] C R Camp P J Bauer and P G Hunt ldquoSubsurface dripirrigation lateral spacing and management for cotton in thesoutheastern Coastal plainrdquo Transactions of the American Soci-ety of Agricultural Engineers vol 40 no 4 pp 993ndash999 1997
Submit your manuscripts athttpwwwhindawicom
Nutrition and Metabolism
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Food ScienceInternational Journal of
Agronomy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom
Applied ampEnvironmentalSoil Science
Volume 2014
AgricultureAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
PsycheHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BiodiversityInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Plant GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biotechnology Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Forestry ResearchInternational Journal of
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Journal of BotanyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
EcologyInternational Journal of
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Veterinary Medicine International
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Cell BiologyInternational Journal of
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Evolutionary BiologyInternational Journal of
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4 The Scientific World Journal
CH4flux were calculated by the linear increase of the gas
concentration at each sampling time (0 10 20 and 30min)sample sets were rejected unless the correlation coefficient(R2) for the linear regression is greater than 09 (07 for smallflux rates) All flux rates were adjusted for air temperature airpressure and area and volume of the chamber [24] AverageGHG fluxes were calculated by triplicate plots Seasonalaccumulation amounts of GHG emissions were calculated bythe emissions between every two adjacent intervals of themeasurements
24 Soil Temperature Moisture and Mineral N ContentSoil temperature and soil moisture were measured at fourdifferent points near the area covered by the chamber Soiltemperature was taken at 5 cm depth Soil moisture wasdetermined using a TDR (time domain reflectometer) [25]
Surface soil samples (0ndash20 cm) at the experiment plotsclose to the chamber covered area were collected for theanalysis of soil mineral N (ammonium and nitrate) contentsat the same day as the gas sampling during the cotton growthseason Fresh soil samples were extracted with 001M CaCl
2
in a 1 10 ratio of soil to extractant The concentrations ofammonium and nitrate in the extract were analyzed usingcontinuous flow analytical system [26] Cotton yield wasrecorded at cotton harvest
25 Statistical Analyses Differences in seasonal N2O and
CH4emissions soil temperature soil Nmineral contents and
cotton yield as affected by irrigationmethods and fertilizationregimes were examined by using a two-way analysis ofvariance (ANOVA) The statistical analysis was carried outusing SPSS 200 (IBM SPSS Statistics Chicago IL USA)
3 Results
31 Soil Characteristics CottonYield andWaterUse EfficiencyThe soil moisture under FC and FB was significantly higherthan that under DC and DB on June 30 July 14 and July 28while on other days the soil moisture with FC and FB wasclose to that with DC and DB (Figure 2(a)) The soil tem-peratures during cotton growing season were significantlyhigher with DC and DB than with FC and FB during thebud stage (119875 lt 005) (Table 2) As compared with FC DCshowed significantly lower soil temperature during floweringand boll-forming stage (119875 lt 005) (Table 2) Howeverfertilization regimes had no effect on soil temperature Thesoil NO
3
minus-N contents were significantly higher with FC andFB than with DC and DB during the bud stage and thatwith FB was significantly higher than those with FC DC andDB during the flowering and boll-forming stage (119875 lt 005)(Table 2 Figure 3(b)) whichwas caused by the topdressing ofN fertilizer in furrow irrigation plots This topdressing eventalso led to a peak in soil NH
4
+-N contents with FC and FB onJune 23 and June 30 (Figure 3(c))
Although there was no significant difference betweenthe cotton yield among these four treatments the wateruse efficiency (WUE) calculated on cotton yield per unitirrigation volume was significantly higher with DC and DB
than that with FCby 538 and 602 respectively (119875 lt 005)(Table 3)
32 N2O Fluxes The N
2O flux rates with FC varied from
70 120583gmminus2 hminus1 to 3209 120583gmminus2 hminus1 during the cotton grow-ing season with two flux peaks on June 30 and July 21(Figure 4(a)) As compared with FC the N
2O flux rates of
FB were relatively stable and lower Under DC the N2O
flux rates were relatively lower among the sampling datescomparing to FC except a flux peak on August 9 On mostdays the N
2O flux rates with DB were close to that with
DC (Figure 4(a)) The accumulated N2O emissions during
the cotton growing season were significantly lower with FBDC and DB than that with FC by 288 361 and 376respectively (119875 lt 005) (Table 4) At different growth stagesthe highest N
2O flux rate under FC DC and DB appeared
at the flowering and boll-forming stage while FB appearedat the bud stage (Figure 4(b)) The N
2O flux rate with FC
performed differently with other three treatments at theflowering and boll-forming stage and the bud stage (119875 lt005) No significant difference was observed between DCand DB during the whole period
33 CH4Fluxes The CH
4flux rates under FC DC and
DB were below zero on most sampling days indicating thatcotton fields were the sink of CH
4except under FB for most
of the time of the cotton growing season (Figure 5(a)) TheCH4flux rates were similar under the four treatments in
May and June but diverged after June The highest uptake ofCH4appeared at the flowering and boll-forming stage under
FC and DB while it appeared at the bud stage under DC(Figure 5(b)) The accumulated CH
4emissions during the
cotton growing season were significantly lower with DC andDB than that with FB by 2645 and 2267 respectively(119875 lt 005) (Table 4) Although the accumulated CH
4
emission under FC was 1542 lower than that with FB therewas little difference between the two treatments
34 Yield-Scaled GWP The total GWP of N2O and CH
4
emissions during cotton growing season was 10289 1462343509 and 49649 under treatments of DC DB FC and FBrespectively (Figure 6(a)) Cotton fields under DC DB andFC were all sinks for CH
4 which reduced the contribution
of N2O emission to the overall GWP by 683 539
and 144 respectively The yield-scaled GWP calculated byGWP per unit cotton yield with FC and FB were significantlyhigher than those with DC and DB (119875 lt 001) (Figure 6(b))As compared with FC DC and DB were 801 and 722lower in yield-scaled GWP respectively Irrigation methodsshowed extremely significant effect on the total GWP andyield-scaled GWP (119875 lt 001) while fertilization regimes hadno effect on both
4 Discussion
In the present study it was observed that the soil temperatureduring cotton growing season was higher with DC and DBthan with FC and FB in most of the time during cotton
The Scientific World Journal 5
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 10
10
20
30
40
FCDCFB
DB
0
30
60
90
120
Prec
ipita
tion
(mm
)
Precipitation
Volu
met
ric so
il w
ater
cont
ent (
)
(a)
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 10
500
1000
1500
2000
FC FBDC DB
Irrig
atio
n vo
lum
e (m
3ha
minus1)
(b)
Figure 2 Effects of different irrigation methods and fertilization regimes on soil moisture precipitation and volume of irrigation waterduring cotton growing season
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 110
15
20
25
30
35
FCDC
FBDB
Soil
tem
pera
ture
(∘C)
(a)
FCDC
FBDB
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 10
50
100
150
200
250
NO
3ndashN
(mg k
gminus1)
(b)
FCDC
FBDB
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 10
2
4
6
NH
3ndashN
(mg k
gminus1)
(c)
Figure 3 Effects of different irrigation methods and fertilization regimes on soil temperature and mineral N contents during cotton growingseason
growing season for the plastic film mulching A similarresult was found in the previous study for different irrigationmethods in maize field in China [27]The plastic film usuallyprevents the evaporation of soil moisture [22] However thedifference of the soil moisture between four treatments wasprimarily attributed to the water supply regimes (Figure 2)The plastic film showed little effect on maintenance of soilmoisture in the present study Biochar can efficiently retain
soil moisture due to its special physical structure [18] whichwas consistent with our results under DC and DB
The emissions of N2O and CH
4from cotton field were
investigated under different irrigation methods and fertil-ization regimes in an arid area of northwestern China Theaccumulated N
2O emissions during cotton growth season in
this study were lower than that from semiarid cotton fieldin northern China [4] and arid cotton fields in Uzbekistan
6 The Scientific World Journal
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 10
100
200
300
400
FCDC
FBDB
N2O
(120583g m
minus2
hminus1)
(a)
Seedling stage Bud stage Flowering and boll-forming stage
Boll opening 0
30
60
90
120
FCDC
FBDB
stage
N2O
(120583g m
minus2
hminus1)
(b)
Figure 4 Effects of different irrigation methods and fertilization regimes on N2O flux rates during cotton growing season
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 1
0
5
10
CH4
(mg m
minus2
hminus1)
minus5
minus10
FCDC
FBDB
(a)
Seedling stage Bud stage Flowering and boll-forming stage
Boll opening
00
15
30
minus15
minus30
stage
CH4
(mg m
minus2
hminus1)
FCDC
FBDB
(b)
Figure 5 Effects of different irrigation methods and fertilization regimes on CH4flux rates during cotton growing season
[6] but higher than the N2O emissions from semiarid cotton
field in Pakistan [5] The variance in N2O emission among
different ecosites might be attributed to the difference in Nfertilizer application rate irrigation climate factors and soilproperties [28ndash33] Here lower level of N
2O emission from
cotton field was found under FB DC and DB in relation toFC with a high N fertilizer application rate (300 kgNhaminus1)(Table 4)The relatively lowerN
2Oemission from cotton field
under drip irrigation treatments was mainly attributed to thewater supply regime and N fertilizer dressing method (so-called fertigation) in drip irrigation system which favoreddecrease in N
2O emission In detail the soil moisture was
lower in cotton field with drip irrigation treatments than thatwith FC during the bud stage which was the main fertiliza-tion time of FC Previous studies reported that soilmoisture isa key factor in regulation of N
2O emission from agricultural
soil For instance theN2Oemissionwas enhanced alongwith
increased soil moisture in a given range due to the improveddenitrification [34ndash36] Therefore the relatively lower soilmoisture in cotton field withDC andDB during the bud stagecould reduce the N
2O emission more effectively than that
with FC Furthermore the decreased N fertilizer was directly
fertigated to the rhizosphere of cotton plants in drip irrigationtreatments with more times but less application rate pertimeThis N fertilizer dressing method could also improve Nuptake of cotton plant but decrease the soil inorganic N pool(NO3
minus-N and NH4
+-N) (Table 2) and hence reduce N sourceforN2Oemission whichwas significantly correlatedwith soil
N [37] However the observed reduction in N2O emission
caused by drip irrigationwas less than that in previous studiesconducted in the melon and tomato fields [8ndash10] This mightbe related to higher N fertilizer application rate in this study(300 kgNhaminus1) suggesting that the mitigation effect of dripirrigation onN
2Omay be depressed with a higher N fertilizer
application rateAlthough FB and FC used the same irrigation system
FB showed lower N2O emission than FC for the addition of
biochar A similar result was found in wheat field [14 15]However the effect of biochar on N
2O emissions under DB
and DC was covered up by the effect of drip irrigationBiochar had been shown to efficiently retain NH
4
+ via cationexchange by its developed specific surface area and surfacenegative charge density [38] Then the retained N wouldbe slowly released for plant growth thus biochar could
The Scientific World Journal 7
FC DC FB DB
0
500
1000
1500G
WP
(kg
CO2
eqha
minus1)
minus500
CH4
N2O
(a) Overall GWP
FC DC FB DB0
100
200
300
400
500
Yiel
d-sc
aled
GW
P (k
gCO
2eq
haminus1)
(b) Yield-scaled GWP
Figure 6 Overall GWP of GHGs (a) and yield-scaled GWP (b) for different treatmentsThe error bar in (a) was the standard error of overallGWP of N
2O and CH
4emissions
Table 2 Effects of different irrigation methods and fertilization regimes on major soil characteristics Values are means plusmn standard deviationof three replicates Different small letters in the same column refer to significant difference between treatments at 119875 lt 005 level
Seedling stage Bud stage Flowering and boll-forming stage Boll opening stageSoil moisture ()
FC 1679 plusmn 037b 1863 plusmn 025a 2046 plusmn 104a 1600 plusmn 125bDC 1728 plusmn 005b 1224 plusmn 013c 1979 plusmn 100a 1881 plusmn 113aFB 1819 plusmn 035ab 1892 plusmn 035a 1952 plusmn 085a 1416 plusmn 150bDB 1965 plusmn 071a 1493 plusmn 069b 2311 plusmn 082a 1870 plusmn 156a
Soil temperature (∘C)FC 2401 plusmn 033a 2455 plusmn 012b 212 plusmn 012b 1853 plusmn 010aDC 2398 plusmn 012a 2629 plusmn 025a 2255 plusmn 015a 1829 plusmn 027aFB 2428 plusmn 019a 2441 plusmn 036b 2178 plusmn 037ab 1803 plusmn 037aDB 2392 plusmn 009a 2580 plusmn 037a 2211 plusmn 033ab 1800 plusmn 005a
Soil NO3
minus-N (mg kgminus1)FC 10082 plusmn 403a 14582 plusmn 352a 5638 plusmn 668b 2694 plusmn 418aDC 10844 plusmn 339a 1980 plusmn 144b 4611 plusmn 129b 3877 plusmn 515aFB 9824 plusmn 686a 15594 plusmn 1238a 7694 plusmn 249a 3726 plusmn 012aDB 10475 plusmn 531a 2554 plusmn 080b 4113 plusmn 490b 3919 plusmn 645a
Soil NO4
+-N (mg kgminus1)FC 214 plusmn 028a 198 plusmn 041ab 138 plusmn 019a 046 plusmn 008aDC 214 plusmn 021a 107 plusmn 013b 096 plusmn 001a 036 plusmn 008aFB 217 plusmn 005a 229 plusmn 016a 124 plusmn 024a 034 plusmn 005aDB 204 plusmn 011a 129 plusmn 006b 101 plusmn 012a 057 plusmn 016a
Table 3 Effects of different irrigationmethods and fertilization regimes on cotton yield and water use efficiency Values are means plusmn standarddeviation of three replicates Different small letters in the same column refer to significant difference between treatments at 119875 lt 005 level
FC DC FB DBCotton yield (Mg haminus1) 176 plusmn 016a 202 plusmn 010a 194 plusmn 017a 211 plusmn 014aWater use efficiency (kgmminus3) 029 plusmn 003b 045 plusmn 002a 032 plusmn 003b 047 plusmn 003a
8 The Scientific World Journal
Table 4 Effects of different irrigation methods and fertilizationregimes on accumulated N2O and CH4 emissions during cottongrowing season Values are means plusmn standard deviation of threereplicates Different small letters in the same column refer tosignificant difference between treatments at 119875 lt 005 level
N2O (kg haminus1) CH4 (kg haminus1)
FC 171 plusmn 013a minus292 plusmn 096abDC 109 plusmn 011b minus887 plusmn 185bFB 121 plusmn 007b 539 plusmn 491aDB 104 plusmn 006b minus684 plusmn 107b
coordinate the mineral N availability and plant uptake Thiswould reduce the amount of N available for denitrificationand lost as N
2O [18] On the other hand decreases in
emissions of N2O in soil amended with biochar might be
attributed to improved aeration and porosity for its developedmicrostructure which might lead to lower denitrificationrates and alter the N
2O-to-N
2ratio during denitrification
[16]The present study indicated that the arid cotton fields
under FC DC and DB were the sinks of CH4 while FB was
the source of CH4 This was consistent with the results of
previous studies with different irrigation methods conductedin upland field [39ndash41] However drip irrigation was asource of CH
4in the study in cotton field [22] which was
inconsistent with the present results This might be relatedto the different rate of irrigation and fertilization Uplandfields are normally net sinks for CH
4 since the consumption
exceeds the production in CH4[42] The dry soil in upland
field limited the CH4emission however it did have a
possibility to become a source after rainfall within severaldays orweeks [43 44] Comparing theCH
4emission between
DC and FC it was shown that DC increased the uptakeof CH
4for the relative lower soil moisture in most of the
time during cotton growing season (Figure 2(a)) The mainfactor affectingCH
4uptake in summerwas soilmoisture [45]
which plays a critical role inCH4consumption [46] Decrease
in soil moisture enhanced CH4oxidation through improving
CH4diffusion from atmosphere into soil pore spaces [47] and
through gas diffusivity to control microbial oxidation whichchanges inversely with soil moisture [48 49]
In our study the addition of biochar increased CH4
emissions by 2846 higher with FB than that with FC whilethe uptake of CH
4with DB was 229 lower than that with
DC The result was in good agreement with previous studythat biochar addition promoted CH
4emissions of the upland
soil [17] However other studies had reported that biocharamendment reduces CH
4emissions as compared with the
control [18 19] The inconsistence might be attributed to thesoil type agricultural management and biochar type On onehand the addition of biochar increased the substrate sup-ply and created a favorable environment for methanogenicactivity On the other hand the CH
4emission from acid
soil was usually much lower than that from neutral soil[50] Biochar addition could increase soil PH which was abenefit for methanogenic bacteria Furthermore increasedsoil aeration due to increased porosity could increase CH
4
diffusion Biochar might play a more important role underpaddy fields compared with straw returning directly whichwould increase CH
4emission obviously [51]
There was significant difference between drip irrigationtreatments and furrow irrigation treatments in the total GWPof N2O and CH
4emissions (119875 lt 001) while fertilization
regimes showed little effect (Figure 6) The average yield-scaledGWPwas 801 and 722 lowerwithDCandDB thanthat with FC indicating that drip irrigation couldmitigate theyield-scaled GHG emissions from cotton field In previousstudies cotton yield was higher with drip irrigation thanthat with furrow irrigation [52] which agreed with ourstudy Although the difference of cotton yield between fourtreatments was insignificant WUE was significantly higherwith DC and DB than that with FC by 538 and 602respectively (119875 lt 005) (Table 3) WUE represented inthis study (from 0263 kgmminus3 to 0527 kgmminus3) were lowerthan that from the studies in Turkey where it rangedfrom 0508 kgmminus3 to 0648 kgmminus3 or from 076 kgmminus3 to146 kgmminus3 [52 53]The variance inWUE in different ecositescould be related to climate plant number varietal differencesand irrigation amount [54] It indicated that drip irrigationsignificantly increased WUE of cotton plants in relation tofurrow irrigation The relative higher WUE with DC and DBwas related to improved fertilizer efficiency and depressedleaching potential in drip irrigation system [55]
5 Conclusions
Irrigation methods significantly affected the GHG emissionsfrom cotton field in arid northwestern China Biochar addi-tion increased CH
4emissions and decreased N
2O emissions
The water supply and N fertilizer dressing method played akey role in regulating gas emissions Drip irrigation treat-ments (DC and DB) remarkably reduced GHG emissionscompared with furrow irrigation treatments (FC and FB) Inaddition drip irrigation treatments (DC and DB) had higheryield and WUE compared to furrow irrigation treatments(FC and FB) Thus mulched-drip irrigation with conven-tional fertilization or conventional fertilization + biocharshould be a better approach to increase cotton yield withdepressed GHG emissions in arid northwestern China
Abbreviations
GHG Greenhouse gasGWP Global warming potentialWUE Water use efficiency
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgment
This work was financially supported by the opened subjectof Xinjiang Key Laboratory of Water Cycle and Utilization inArid Zone (Grant no XJYS0907-2010-03)
The Scientific World Journal 9
References
[1] IPCC Climate Change 2007 The Physical Science Basis Cam-bridge University Press Cambridge UK 2007
[2] A F Bouwman L J M Boumans and N H Baffes GlobalEstimates of Gaseous Emissions of NH
3 NO and N
2O from
Agricultural Land Food and Agriculture Organisation RomeItaly 2001
[3] FAOSTAT 2002 httpfaostatfaoorg[4] C Liu X Zheng Z Zhou et al ldquoNitrous oxide and nitric oxide
emissions from an irrigated cotton field in Northern ChinardquoPlant and Soil vol 332 no 1-2 pp 123ndash134 2010
[5] TMahmood RAli J Iqbal andURobab ldquoNitrous oxide emis-sion from an irrigated cotton field under semiarid subtropicalconditionsrdquo Biology and Fertility of Soils vol 44 no 5 pp 773ndash781 2008
[6] C Scheer R Wassmann K Kienzler N Ibragimov andR Eschanov ldquoNitrous oxide emissions from fertilized irri-gated cotton (Gossypium hirsutum L) in the Aral Sea BasinUzbekistan influence of nitrogen applications and irrigationpracticesrdquo Soil Biology and Biochemistry vol 40 no 2 pp 290ndash301 2008
[7] J Li J Zhang and L Ren ldquoWater and nitrogen distributionas affected by fertigation of ammonium nitrate from a pointsourcerdquo Irrigation Science vol 22 no 1 pp 19ndash30 2003
[8] C M Kallenbach D E Rolston and W R Horwath ldquoCovercropping affects soil N
2O and CO
2emissions differently
depending on type of irrigationrdquo Agriculture Ecosystems andEnvironment vol 137 no 3-4 pp 251ndash260 2010
[9] L Sanchez-Martın A Arce A Benito L Garcia-Torres andA Vallejo ldquoInfluence of drip and furrow irrigation systems onnitrogen oxide emissions from a horticultural croprdquo Soil Biologyand Biochemistry vol 40 no 7 pp 1698ndash1706 2008
[10] L Sanchez-Martın A Meijide L Garcia-Torres and A VallejoldquoCombination of drip irrigation and organic fertilizer formitigating emissions of nitrogen oxides in semiarid climaterdquoAgriculture Ecosystems and Environment vol 137 no 1-2 pp99ndash107 2010
[11] J Lehmann ldquoBio-energy in the blackrdquo Frontiers in Ecology andthe Environment vol 5 no 7 pp 381ndash387 2007
[12] M Fowles ldquoBlack carbon sequestration as an alternative tobioenergyrdquo Biomass and Bioenergy vol 31 no 6 pp 426ndash4322007
[13] M Rondon J A Ramirez and J Lehmann ldquoCharcoal additionsreduce net emissions of greenhouse gases to the atmosphererdquo inProceedings of the 3rd USDA Symposium on Greenhouse Gasesand Carbon Sequestration p 208 Baltimore Md USA March2005
[14] A Aguilar-Chavez M Dıaz-Rojas M del Rosario Cardenas-Aquino L Dendooven and M Luna-Guido ldquoGreenhouse gasemissions from a wastewater sludge-amended soil cultivatedwith wheat (Triticum spp L) as affected by different applicationrates of charcoalrdquo Soil Biology and Biochemistry vol 52 pp 90ndash95 2012
[15] S Castaldi M Riondino S Baronti et al ldquoImpact of biocharapplication to a Mediterranean wheat crop on soil microbialactivity and greenhouse gas fluxesrdquo Chemosphere vol 85 no9 pp 1464ndash1471 2011
[16] B P Singh B J Hatton B Singh A L Cowie and A KathurialdquoInfluence of biochars on nitrous oxide emission and nitrogenleaching from two contrasting soilsrdquo Journal of EnvironmentalQuality vol 39 no 4 pp 1224ndash1235 2010
[17] J Wang X Pan Y Liu X Zhang and Z Xiong ldquoEffects ofbiochar amendment in two soils on greenhouse gas emissionsand crop productionrdquo Plant and Soil vol 360 no 1-2 pp 287ndash298 2012
[18] K Karhu T Mattila I Bergstrom and K Regina ldquoBiocharaddition to agricultural soil increased CH
4uptake and water
holding capacitymdashresults from a short-term pilot field studyrdquoAgriculture Ecosystems and Environment vol 140 no 1-2 pp309ndash313 2011
[19] C Scheer P R Grace D W Rowlings S Kimber and L vanZwieten ldquoEffect of biochar amendment on the soil-atmosphereexchange of greenhouse gases from an intensive subtropicalpasture in northernNew SouthWales AustraliardquoPlant and Soilvol 345 no 1 pp 47ndash58 2011
[20] Z Li R Zhang X Wang J Wang C Zhang and C TianldquoCarbon dioxide fluxes and concentrations in a cotton fieldin northwestern China effects of plastic mulching and dripirrigationrdquo Pedosphere vol 21 no 2 pp 178ndash185 2011
[21] Q Zhang L Yang J Wang H Luo Y Zhang and WZhang ldquoEffects of different irrigation methods and fertilizationmeasures on soil respiration and its component contribution incotton field in arid regionrdquo Scientia Agricultura Sinica vol 25no 12 pp 2420ndash2430 2012 (Chinese)
[22] Z Li R Zhang X Wang F Chen D Lai and C Tian ldquoEffectsof plastic film mulching with drip irrigation on N
2O and CH
4
emissions fromcotton fields in arid landrdquo Journal of AgriculturalScience 2013
[23] FAOIAEA Measurement of Methane and Nitrous Oxide Emis-sion from Agriculture A Joint Undertakong by the Food andAgriculture Organization of United Nations and InternationalAtomic Energy Agency International Atomic Energy AgencyVienna Austria 1992
[24] Y Huang J Jiang L Zong Q Zhou R L Sass and F MFisher ldquoInfluence of planting density and precipitation on N
2O
emission from a winter wheat fieldrdquo Environmental Science vol22 no 6 pp 20ndash23 2001 (Chinese)
[25] G C Topp J L Davis and A P Annan ldquoElectromagneticdetermination of soil water content measurements in coaxialtransmission linesrdquoWater Resources Research vol 16 no 3 pp574ndash582 1980
[26] R Lu Soil Agricultural Chemistry Analytical Method ChinaAgricultural Science and Technology Press Beijing China2000
[27] L Zhou F Li S Jin and Y Song ldquoHow two ridges andthe furrow mulched with plastic film affect soil water soiltemperature and yield of maize on the semiarid Loess Plateauof Chinardquo Field Crops Research vol 113 no 1 pp 41ndash47 2009
[28] J Clemens M P Schillinger H Goldbach and B HuweldquoSpatial variability of N
2O emissions and soil parameters of an
arable silt loammdasha field studyrdquo Biology and Fertility of Soils vol28 no 4 pp 403ndash406 1999
[29] K InubushiM A Barahona andK Yamakawa ldquoEffects of saltsand moisture content on N
2O emission and nitrogen dynamics
in Yellow soil and Andosol in model experimentsrdquo Biology andFertility of Soils vol 29 no 4 pp 401ndash407 1999
[30] B J Joslashrgensen and R N Joslashrgensen ldquoField-scale and laboratorystudy of factors affecting N
2O emissions from a rye stubble field
on sandy loam soilrdquo Biology and Fertility of Soils vol 25 no 4pp 366ndash371 1997
[31] A R Mosier and Z Zhu ldquoChanges in patterns of fertilizernitrogen use in Asia and its consequences for N
2O emissions
10 The Scientific World Journal
from agricultural systemsrdquo Nutrient Cycling in Agroecosystemsvol 57 no 1 pp 107ndash117 2000
[32] R Ruser H Flessa R Schilling F Beese and J C MunchldquoEffect of crop-specific field management and N fertilizationon N2O emissions from a fine-loamy soilrdquo Nutrient Cycling in
Agroecosystems vol 59 no 2 pp 177ndash191 2001[33] C Song and J Zhang ldquoEffects of soil moisture temperature
and nitrogen fertilization on soil respiration and nitrous oxideemission duringmaize growth period in northeast ChinardquoActaAgriculturae Scandinavica B Soil and Plant Science vol 59 no2 pp 97ndash106 2009
[34] D M Linn and J W Doran ldquoEffect of water-filled pore spaceon carbon dioxide and nitrous oxide production in tilled andnontilled soilsrdquo Soil Science Society of America Journal vol 48no 6 pp 1267ndash1272 1984
[35] X J Liu A R Mosier A D Halvorson C A Reule andF S Zhang ldquoDinitrogen and N
2O emissions in arable soils
effect of tillage N source and soil moisturerdquo Soil Biology andBiochemistry vol 39 no 9 pp 2362ndash2370 2007
[36] L Sanchez-Martın A Vallejo J Dick and U M Skiba ldquoTheinfluence of soluble carbon and fertilizer nitrogen on nitricoxide and nitrous oxide emissions from two contrasting agri-cultural soilsrdquo Soil Biology and Biochemistry vol 40 no 1 pp142ndash151 2008
[37] Z Mu S D Kimura Y Toma and R Hatano ldquoNitrous oxidefluxes from upland soils in central Hokkaido Japanrdquo Journal ofEnvironmental Sciences vol 20 no 11 pp 1312ndash1322 2008
[38] B Liang J Lehmann D Solomon et al ldquoBlack carbon increasescation exchange capacity in soilsrdquo Soil Science Society of AmericaJournal vol 70 no 5 pp 1719ndash1730 2006
[39] P Boeckx and O Van Cleemput ldquoEstimates of N2O and CH
4
fluxes from agricultural lands in various regions in EuroperdquoNutrient Cycling in Agroecosystems vol 60 no 1ndash3 pp 35ndash472001
[40] J A MacDonald U Skiba L J Sheppard et al ldquoThe effectof nitrogen deposition and seasonal variability on methaneoxidation and nitrous oxide emission rates in an upland spruceplantation andmoorlandrdquoAtmospheric Environment vol 31 no22 pp 3693ndash3706 1997
[41] S C Whalen ldquoInfluence of N and non-N salts on atmosphericmethane oxidation by upland boreal forest and tundra soilsrdquoBiology and Fertility of Soils vol 31 no 3-4 pp 279ndash287 2000
[42] J P Megonigal and A B Guenther ldquoMethane emissions fromupland forest soils and vegetationrdquo Tree Physiology vol 28 no4 pp 491ndash498 2008
[43] E A Davidson F Y Ishida and D C Nepstad ldquoEffects ofan experimental drought on soil emissions of carbon dioxidemethane nitrous oxide and nitric oxide in a moist tropicalforestrdquo Global Change Biology vol 10 no 5 pp 718ndash730 2004
[44] F LWang and J R Bettany ldquoMethane emission fromCanadianprairie and forest soils under short term flooding conditionsrdquoNutrient Cycling in Agroecosystems vol 49 no 1ndash3 pp 197ndash2021997
[45] R BrummeandWBorken ldquoSite variation inmethane oxidationas affected by atmospheric deposition and type of temperateforest ecosystemrdquo Global Biogeochemical Cycles vol 13 no 2pp 493ndash501 1999
[46] A P S Adamsen and G M King ldquoMethane consumption intemperate and subarctic forest soils rates vertical zonation andresponses to water and nitrogenrdquo Applied and EnvironmentalMicrobiology vol 59 no 2 pp 485ndash490 1993
[47] M S Castro P A Steudler J M Melillo J D Aber and R DBowden ldquoFactors controlling atmospheric methane consump-tion by temperate forest soilsrdquoGlobal Biogeochemical Cycles vol9 no 1 pp 1ndash10 1995
[48] B C Ball K A Smith L Klemedtsson et al ldquoThe influence ofsoil gas transport properties onmethane oxidation in a selectionof northern European soilsrdquo Journal of Geophysical Research Dvol 102 no 19 pp 23309ndash23317 1997
[49] K A Smith T Ball F Conen K E Dobbie J Masshederand A Rey ldquoExchange of greenhouse gases between soil andatmosphere interactions of soil physical factors and biologicalprocessesrdquo European Journal of Soil Science vol 54 no 4 pp779ndash791 2003
[50] H Feng G Cheng and L An ldquoMicrobial-mediated methanecycle in soils and global change a reviewrdquo Journal of Glaciologyand Geocryology vol 26 no 4 pp 411ndash419 2006 (Chinese)
[51] Y YanDWang and J Zheng ldquoAdvances in effects of biochar onthe soil N
2O and CH
4emissionsrdquo Chinese Agricultural Science
Bulletin vol 29 no 8 pp 140ndash146 2013 (Chinese)[52] OCetin andL Bilgel ldquoEffects of different irrigationmethods on
shedding and yield of cottonrdquo Agricultural Water Managementvol 54 no 1 pp 1ndash15 2002
[53] NDagdelenaH Basalb E Yılmaza T Gurbuza and S AkcayaldquoDifferent drip irrigation regimes affect cotton yield water useefficiency and fiber quality in western Turkeyrdquo AgriculturalWater Management vol 96 no 1 pp 110ndash120 2009
[54] N Ibragimov S R Evett Y Esanbekov B S Kamilov LMirzaev and J P A Lamers ldquoWater use efficiency of irrigatedcotton in Uzbekistan under drip and furrow irrigationrdquo Agri-cultural Water Management vol 90 no 1-2 pp 112ndash120 2007
[55] C R Camp P J Bauer and P G Hunt ldquoSubsurface dripirrigation lateral spacing and management for cotton in thesoutheastern Coastal plainrdquo Transactions of the American Soci-ety of Agricultural Engineers vol 40 no 4 pp 993ndash999 1997
Submit your manuscripts athttpwwwhindawicom
Nutrition and Metabolism
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Food ScienceInternational Journal of
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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
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Microbiology
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom
Applied ampEnvironmentalSoil Science
Volume 2014
AgricultureAdvances in
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BiodiversityInternational Journal of
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ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
GenomicsInternational Journal of
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Plant GenomicsInternational Journal of
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Biotechnology Research International
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Evolutionary BiologyInternational Journal of
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The Scientific World Journal 5
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 10
10
20
30
40
FCDCFB
DB
0
30
60
90
120
Prec
ipita
tion
(mm
)
Precipitation
Volu
met
ric so
il w
ater
cont
ent (
)
(a)
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 10
500
1000
1500
2000
FC FBDC DB
Irrig
atio
n vo
lum
e (m
3ha
minus1)
(b)
Figure 2 Effects of different irrigation methods and fertilization regimes on soil moisture precipitation and volume of irrigation waterduring cotton growing season
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 110
15
20
25
30
35
FCDC
FBDB
Soil
tem
pera
ture
(∘C)
(a)
FCDC
FBDB
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 10
50
100
150
200
250
NO
3ndashN
(mg k
gminus1)
(b)
FCDC
FBDB
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 10
2
4
6
NH
3ndashN
(mg k
gminus1)
(c)
Figure 3 Effects of different irrigation methods and fertilization regimes on soil temperature and mineral N contents during cotton growingseason
growing season for the plastic film mulching A similarresult was found in the previous study for different irrigationmethods in maize field in China [27]The plastic film usuallyprevents the evaporation of soil moisture [22] However thedifference of the soil moisture between four treatments wasprimarily attributed to the water supply regimes (Figure 2)The plastic film showed little effect on maintenance of soilmoisture in the present study Biochar can efficiently retain
soil moisture due to its special physical structure [18] whichwas consistent with our results under DC and DB
The emissions of N2O and CH
4from cotton field were
investigated under different irrigation methods and fertil-ization regimes in an arid area of northwestern China Theaccumulated N
2O emissions during cotton growth season in
this study were lower than that from semiarid cotton fieldin northern China [4] and arid cotton fields in Uzbekistan
6 The Scientific World Journal
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 10
100
200
300
400
FCDC
FBDB
N2O
(120583g m
minus2
hminus1)
(a)
Seedling stage Bud stage Flowering and boll-forming stage
Boll opening 0
30
60
90
120
FCDC
FBDB
stage
N2O
(120583g m
minus2
hminus1)
(b)
Figure 4 Effects of different irrigation methods and fertilization regimes on N2O flux rates during cotton growing season
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 1
0
5
10
CH4
(mg m
minus2
hminus1)
minus5
minus10
FCDC
FBDB
(a)
Seedling stage Bud stage Flowering and boll-forming stage
Boll opening
00
15
30
minus15
minus30
stage
CH4
(mg m
minus2
hminus1)
FCDC
FBDB
(b)
Figure 5 Effects of different irrigation methods and fertilization regimes on CH4flux rates during cotton growing season
[6] but higher than the N2O emissions from semiarid cotton
field in Pakistan [5] The variance in N2O emission among
different ecosites might be attributed to the difference in Nfertilizer application rate irrigation climate factors and soilproperties [28ndash33] Here lower level of N
2O emission from
cotton field was found under FB DC and DB in relation toFC with a high N fertilizer application rate (300 kgNhaminus1)(Table 4)The relatively lowerN
2Oemission from cotton field
under drip irrigation treatments was mainly attributed to thewater supply regime and N fertilizer dressing method (so-called fertigation) in drip irrigation system which favoreddecrease in N
2O emission In detail the soil moisture was
lower in cotton field with drip irrigation treatments than thatwith FC during the bud stage which was the main fertiliza-tion time of FC Previous studies reported that soilmoisture isa key factor in regulation of N
2O emission from agricultural
soil For instance theN2Oemissionwas enhanced alongwith
increased soil moisture in a given range due to the improveddenitrification [34ndash36] Therefore the relatively lower soilmoisture in cotton field withDC andDB during the bud stagecould reduce the N
2O emission more effectively than that
with FC Furthermore the decreased N fertilizer was directly
fertigated to the rhizosphere of cotton plants in drip irrigationtreatments with more times but less application rate pertimeThis N fertilizer dressing method could also improve Nuptake of cotton plant but decrease the soil inorganic N pool(NO3
minus-N and NH4
+-N) (Table 2) and hence reduce N sourceforN2Oemission whichwas significantly correlatedwith soil
N [37] However the observed reduction in N2O emission
caused by drip irrigationwas less than that in previous studiesconducted in the melon and tomato fields [8ndash10] This mightbe related to higher N fertilizer application rate in this study(300 kgNhaminus1) suggesting that the mitigation effect of dripirrigation onN
2Omay be depressed with a higher N fertilizer
application rateAlthough FB and FC used the same irrigation system
FB showed lower N2O emission than FC for the addition of
biochar A similar result was found in wheat field [14 15]However the effect of biochar on N
2O emissions under DB
and DC was covered up by the effect of drip irrigationBiochar had been shown to efficiently retain NH
4
+ via cationexchange by its developed specific surface area and surfacenegative charge density [38] Then the retained N wouldbe slowly released for plant growth thus biochar could
The Scientific World Journal 7
FC DC FB DB
0
500
1000
1500G
WP
(kg
CO2
eqha
minus1)
minus500
CH4
N2O
(a) Overall GWP
FC DC FB DB0
100
200
300
400
500
Yiel
d-sc
aled
GW
P (k
gCO
2eq
haminus1)
(b) Yield-scaled GWP
Figure 6 Overall GWP of GHGs (a) and yield-scaled GWP (b) for different treatmentsThe error bar in (a) was the standard error of overallGWP of N
2O and CH
4emissions
Table 2 Effects of different irrigation methods and fertilization regimes on major soil characteristics Values are means plusmn standard deviationof three replicates Different small letters in the same column refer to significant difference between treatments at 119875 lt 005 level
Seedling stage Bud stage Flowering and boll-forming stage Boll opening stageSoil moisture ()
FC 1679 plusmn 037b 1863 plusmn 025a 2046 plusmn 104a 1600 plusmn 125bDC 1728 plusmn 005b 1224 plusmn 013c 1979 plusmn 100a 1881 plusmn 113aFB 1819 plusmn 035ab 1892 plusmn 035a 1952 plusmn 085a 1416 plusmn 150bDB 1965 plusmn 071a 1493 plusmn 069b 2311 plusmn 082a 1870 plusmn 156a
Soil temperature (∘C)FC 2401 plusmn 033a 2455 plusmn 012b 212 plusmn 012b 1853 plusmn 010aDC 2398 plusmn 012a 2629 plusmn 025a 2255 plusmn 015a 1829 plusmn 027aFB 2428 plusmn 019a 2441 plusmn 036b 2178 plusmn 037ab 1803 plusmn 037aDB 2392 plusmn 009a 2580 plusmn 037a 2211 plusmn 033ab 1800 plusmn 005a
Soil NO3
minus-N (mg kgminus1)FC 10082 plusmn 403a 14582 plusmn 352a 5638 plusmn 668b 2694 plusmn 418aDC 10844 plusmn 339a 1980 plusmn 144b 4611 plusmn 129b 3877 plusmn 515aFB 9824 plusmn 686a 15594 plusmn 1238a 7694 plusmn 249a 3726 plusmn 012aDB 10475 plusmn 531a 2554 plusmn 080b 4113 plusmn 490b 3919 plusmn 645a
Soil NO4
+-N (mg kgminus1)FC 214 plusmn 028a 198 plusmn 041ab 138 plusmn 019a 046 plusmn 008aDC 214 plusmn 021a 107 plusmn 013b 096 plusmn 001a 036 plusmn 008aFB 217 plusmn 005a 229 plusmn 016a 124 plusmn 024a 034 plusmn 005aDB 204 plusmn 011a 129 plusmn 006b 101 plusmn 012a 057 plusmn 016a
Table 3 Effects of different irrigationmethods and fertilization regimes on cotton yield and water use efficiency Values are means plusmn standarddeviation of three replicates Different small letters in the same column refer to significant difference between treatments at 119875 lt 005 level
FC DC FB DBCotton yield (Mg haminus1) 176 plusmn 016a 202 plusmn 010a 194 plusmn 017a 211 plusmn 014aWater use efficiency (kgmminus3) 029 plusmn 003b 045 plusmn 002a 032 plusmn 003b 047 plusmn 003a
8 The Scientific World Journal
Table 4 Effects of different irrigation methods and fertilizationregimes on accumulated N2O and CH4 emissions during cottongrowing season Values are means plusmn standard deviation of threereplicates Different small letters in the same column refer tosignificant difference between treatments at 119875 lt 005 level
N2O (kg haminus1) CH4 (kg haminus1)
FC 171 plusmn 013a minus292 plusmn 096abDC 109 plusmn 011b minus887 plusmn 185bFB 121 plusmn 007b 539 plusmn 491aDB 104 plusmn 006b minus684 plusmn 107b
coordinate the mineral N availability and plant uptake Thiswould reduce the amount of N available for denitrificationand lost as N
2O [18] On the other hand decreases in
emissions of N2O in soil amended with biochar might be
attributed to improved aeration and porosity for its developedmicrostructure which might lead to lower denitrificationrates and alter the N
2O-to-N
2ratio during denitrification
[16]The present study indicated that the arid cotton fields
under FC DC and DB were the sinks of CH4 while FB was
the source of CH4 This was consistent with the results of
previous studies with different irrigation methods conductedin upland field [39ndash41] However drip irrigation was asource of CH
4in the study in cotton field [22] which was
inconsistent with the present results This might be relatedto the different rate of irrigation and fertilization Uplandfields are normally net sinks for CH
4 since the consumption
exceeds the production in CH4[42] The dry soil in upland
field limited the CH4emission however it did have a
possibility to become a source after rainfall within severaldays orweeks [43 44] Comparing theCH
4emission between
DC and FC it was shown that DC increased the uptakeof CH
4for the relative lower soil moisture in most of the
time during cotton growing season (Figure 2(a)) The mainfactor affectingCH
4uptake in summerwas soilmoisture [45]
which plays a critical role inCH4consumption [46] Decrease
in soil moisture enhanced CH4oxidation through improving
CH4diffusion from atmosphere into soil pore spaces [47] and
through gas diffusivity to control microbial oxidation whichchanges inversely with soil moisture [48 49]
In our study the addition of biochar increased CH4
emissions by 2846 higher with FB than that with FC whilethe uptake of CH
4with DB was 229 lower than that with
DC The result was in good agreement with previous studythat biochar addition promoted CH
4emissions of the upland
soil [17] However other studies had reported that biocharamendment reduces CH
4emissions as compared with the
control [18 19] The inconsistence might be attributed to thesoil type agricultural management and biochar type On onehand the addition of biochar increased the substrate sup-ply and created a favorable environment for methanogenicactivity On the other hand the CH
4emission from acid
soil was usually much lower than that from neutral soil[50] Biochar addition could increase soil PH which was abenefit for methanogenic bacteria Furthermore increasedsoil aeration due to increased porosity could increase CH
4
diffusion Biochar might play a more important role underpaddy fields compared with straw returning directly whichwould increase CH
4emission obviously [51]
There was significant difference between drip irrigationtreatments and furrow irrigation treatments in the total GWPof N2O and CH
4emissions (119875 lt 001) while fertilization
regimes showed little effect (Figure 6) The average yield-scaledGWPwas 801 and 722 lowerwithDCandDB thanthat with FC indicating that drip irrigation couldmitigate theyield-scaled GHG emissions from cotton field In previousstudies cotton yield was higher with drip irrigation thanthat with furrow irrigation [52] which agreed with ourstudy Although the difference of cotton yield between fourtreatments was insignificant WUE was significantly higherwith DC and DB than that with FC by 538 and 602respectively (119875 lt 005) (Table 3) WUE represented inthis study (from 0263 kgmminus3 to 0527 kgmminus3) were lowerthan that from the studies in Turkey where it rangedfrom 0508 kgmminus3 to 0648 kgmminus3 or from 076 kgmminus3 to146 kgmminus3 [52 53]The variance inWUE in different ecositescould be related to climate plant number varietal differencesand irrigation amount [54] It indicated that drip irrigationsignificantly increased WUE of cotton plants in relation tofurrow irrigation The relative higher WUE with DC and DBwas related to improved fertilizer efficiency and depressedleaching potential in drip irrigation system [55]
5 Conclusions
Irrigation methods significantly affected the GHG emissionsfrom cotton field in arid northwestern China Biochar addi-tion increased CH
4emissions and decreased N
2O emissions
The water supply and N fertilizer dressing method played akey role in regulating gas emissions Drip irrigation treat-ments (DC and DB) remarkably reduced GHG emissionscompared with furrow irrigation treatments (FC and FB) Inaddition drip irrigation treatments (DC and DB) had higheryield and WUE compared to furrow irrigation treatments(FC and FB) Thus mulched-drip irrigation with conven-tional fertilization or conventional fertilization + biocharshould be a better approach to increase cotton yield withdepressed GHG emissions in arid northwestern China
Abbreviations
GHG Greenhouse gasGWP Global warming potentialWUE Water use efficiency
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgment
This work was financially supported by the opened subjectof Xinjiang Key Laboratory of Water Cycle and Utilization inArid Zone (Grant no XJYS0907-2010-03)
The Scientific World Journal 9
References
[1] IPCC Climate Change 2007 The Physical Science Basis Cam-bridge University Press Cambridge UK 2007
[2] A F Bouwman L J M Boumans and N H Baffes GlobalEstimates of Gaseous Emissions of NH
3 NO and N
2O from
Agricultural Land Food and Agriculture Organisation RomeItaly 2001
[3] FAOSTAT 2002 httpfaostatfaoorg[4] C Liu X Zheng Z Zhou et al ldquoNitrous oxide and nitric oxide
emissions from an irrigated cotton field in Northern ChinardquoPlant and Soil vol 332 no 1-2 pp 123ndash134 2010
[5] TMahmood RAli J Iqbal andURobab ldquoNitrous oxide emis-sion from an irrigated cotton field under semiarid subtropicalconditionsrdquo Biology and Fertility of Soils vol 44 no 5 pp 773ndash781 2008
[6] C Scheer R Wassmann K Kienzler N Ibragimov andR Eschanov ldquoNitrous oxide emissions from fertilized irri-gated cotton (Gossypium hirsutum L) in the Aral Sea BasinUzbekistan influence of nitrogen applications and irrigationpracticesrdquo Soil Biology and Biochemistry vol 40 no 2 pp 290ndash301 2008
[7] J Li J Zhang and L Ren ldquoWater and nitrogen distributionas affected by fertigation of ammonium nitrate from a pointsourcerdquo Irrigation Science vol 22 no 1 pp 19ndash30 2003
[8] C M Kallenbach D E Rolston and W R Horwath ldquoCovercropping affects soil N
2O and CO
2emissions differently
depending on type of irrigationrdquo Agriculture Ecosystems andEnvironment vol 137 no 3-4 pp 251ndash260 2010
[9] L Sanchez-Martın A Arce A Benito L Garcia-Torres andA Vallejo ldquoInfluence of drip and furrow irrigation systems onnitrogen oxide emissions from a horticultural croprdquo Soil Biologyand Biochemistry vol 40 no 7 pp 1698ndash1706 2008
[10] L Sanchez-Martın A Meijide L Garcia-Torres and A VallejoldquoCombination of drip irrigation and organic fertilizer formitigating emissions of nitrogen oxides in semiarid climaterdquoAgriculture Ecosystems and Environment vol 137 no 1-2 pp99ndash107 2010
[11] J Lehmann ldquoBio-energy in the blackrdquo Frontiers in Ecology andthe Environment vol 5 no 7 pp 381ndash387 2007
[12] M Fowles ldquoBlack carbon sequestration as an alternative tobioenergyrdquo Biomass and Bioenergy vol 31 no 6 pp 426ndash4322007
[13] M Rondon J A Ramirez and J Lehmann ldquoCharcoal additionsreduce net emissions of greenhouse gases to the atmosphererdquo inProceedings of the 3rd USDA Symposium on Greenhouse Gasesand Carbon Sequestration p 208 Baltimore Md USA March2005
[14] A Aguilar-Chavez M Dıaz-Rojas M del Rosario Cardenas-Aquino L Dendooven and M Luna-Guido ldquoGreenhouse gasemissions from a wastewater sludge-amended soil cultivatedwith wheat (Triticum spp L) as affected by different applicationrates of charcoalrdquo Soil Biology and Biochemistry vol 52 pp 90ndash95 2012
[15] S Castaldi M Riondino S Baronti et al ldquoImpact of biocharapplication to a Mediterranean wheat crop on soil microbialactivity and greenhouse gas fluxesrdquo Chemosphere vol 85 no9 pp 1464ndash1471 2011
[16] B P Singh B J Hatton B Singh A L Cowie and A KathurialdquoInfluence of biochars on nitrous oxide emission and nitrogenleaching from two contrasting soilsrdquo Journal of EnvironmentalQuality vol 39 no 4 pp 1224ndash1235 2010
[17] J Wang X Pan Y Liu X Zhang and Z Xiong ldquoEffects ofbiochar amendment in two soils on greenhouse gas emissionsand crop productionrdquo Plant and Soil vol 360 no 1-2 pp 287ndash298 2012
[18] K Karhu T Mattila I Bergstrom and K Regina ldquoBiocharaddition to agricultural soil increased CH
4uptake and water
holding capacitymdashresults from a short-term pilot field studyrdquoAgriculture Ecosystems and Environment vol 140 no 1-2 pp309ndash313 2011
[19] C Scheer P R Grace D W Rowlings S Kimber and L vanZwieten ldquoEffect of biochar amendment on the soil-atmosphereexchange of greenhouse gases from an intensive subtropicalpasture in northernNew SouthWales AustraliardquoPlant and Soilvol 345 no 1 pp 47ndash58 2011
[20] Z Li R Zhang X Wang J Wang C Zhang and C TianldquoCarbon dioxide fluxes and concentrations in a cotton fieldin northwestern China effects of plastic mulching and dripirrigationrdquo Pedosphere vol 21 no 2 pp 178ndash185 2011
[21] Q Zhang L Yang J Wang H Luo Y Zhang and WZhang ldquoEffects of different irrigation methods and fertilizationmeasures on soil respiration and its component contribution incotton field in arid regionrdquo Scientia Agricultura Sinica vol 25no 12 pp 2420ndash2430 2012 (Chinese)
[22] Z Li R Zhang X Wang F Chen D Lai and C Tian ldquoEffectsof plastic film mulching with drip irrigation on N
2O and CH
4
emissions fromcotton fields in arid landrdquo Journal of AgriculturalScience 2013
[23] FAOIAEA Measurement of Methane and Nitrous Oxide Emis-sion from Agriculture A Joint Undertakong by the Food andAgriculture Organization of United Nations and InternationalAtomic Energy Agency International Atomic Energy AgencyVienna Austria 1992
[24] Y Huang J Jiang L Zong Q Zhou R L Sass and F MFisher ldquoInfluence of planting density and precipitation on N
2O
emission from a winter wheat fieldrdquo Environmental Science vol22 no 6 pp 20ndash23 2001 (Chinese)
[25] G C Topp J L Davis and A P Annan ldquoElectromagneticdetermination of soil water content measurements in coaxialtransmission linesrdquoWater Resources Research vol 16 no 3 pp574ndash582 1980
[26] R Lu Soil Agricultural Chemistry Analytical Method ChinaAgricultural Science and Technology Press Beijing China2000
[27] L Zhou F Li S Jin and Y Song ldquoHow two ridges andthe furrow mulched with plastic film affect soil water soiltemperature and yield of maize on the semiarid Loess Plateauof Chinardquo Field Crops Research vol 113 no 1 pp 41ndash47 2009
[28] J Clemens M P Schillinger H Goldbach and B HuweldquoSpatial variability of N
2O emissions and soil parameters of an
arable silt loammdasha field studyrdquo Biology and Fertility of Soils vol28 no 4 pp 403ndash406 1999
[29] K InubushiM A Barahona andK Yamakawa ldquoEffects of saltsand moisture content on N
2O emission and nitrogen dynamics
in Yellow soil and Andosol in model experimentsrdquo Biology andFertility of Soils vol 29 no 4 pp 401ndash407 1999
[30] B J Joslashrgensen and R N Joslashrgensen ldquoField-scale and laboratorystudy of factors affecting N
2O emissions from a rye stubble field
on sandy loam soilrdquo Biology and Fertility of Soils vol 25 no 4pp 366ndash371 1997
[31] A R Mosier and Z Zhu ldquoChanges in patterns of fertilizernitrogen use in Asia and its consequences for N
2O emissions
10 The Scientific World Journal
from agricultural systemsrdquo Nutrient Cycling in Agroecosystemsvol 57 no 1 pp 107ndash117 2000
[32] R Ruser H Flessa R Schilling F Beese and J C MunchldquoEffect of crop-specific field management and N fertilizationon N2O emissions from a fine-loamy soilrdquo Nutrient Cycling in
Agroecosystems vol 59 no 2 pp 177ndash191 2001[33] C Song and J Zhang ldquoEffects of soil moisture temperature
and nitrogen fertilization on soil respiration and nitrous oxideemission duringmaize growth period in northeast ChinardquoActaAgriculturae Scandinavica B Soil and Plant Science vol 59 no2 pp 97ndash106 2009
[34] D M Linn and J W Doran ldquoEffect of water-filled pore spaceon carbon dioxide and nitrous oxide production in tilled andnontilled soilsrdquo Soil Science Society of America Journal vol 48no 6 pp 1267ndash1272 1984
[35] X J Liu A R Mosier A D Halvorson C A Reule andF S Zhang ldquoDinitrogen and N
2O emissions in arable soils
effect of tillage N source and soil moisturerdquo Soil Biology andBiochemistry vol 39 no 9 pp 2362ndash2370 2007
[36] L Sanchez-Martın A Vallejo J Dick and U M Skiba ldquoTheinfluence of soluble carbon and fertilizer nitrogen on nitricoxide and nitrous oxide emissions from two contrasting agri-cultural soilsrdquo Soil Biology and Biochemistry vol 40 no 1 pp142ndash151 2008
[37] Z Mu S D Kimura Y Toma and R Hatano ldquoNitrous oxidefluxes from upland soils in central Hokkaido Japanrdquo Journal ofEnvironmental Sciences vol 20 no 11 pp 1312ndash1322 2008
[38] B Liang J Lehmann D Solomon et al ldquoBlack carbon increasescation exchange capacity in soilsrdquo Soil Science Society of AmericaJournal vol 70 no 5 pp 1719ndash1730 2006
[39] P Boeckx and O Van Cleemput ldquoEstimates of N2O and CH
4
fluxes from agricultural lands in various regions in EuroperdquoNutrient Cycling in Agroecosystems vol 60 no 1ndash3 pp 35ndash472001
[40] J A MacDonald U Skiba L J Sheppard et al ldquoThe effectof nitrogen deposition and seasonal variability on methaneoxidation and nitrous oxide emission rates in an upland spruceplantation andmoorlandrdquoAtmospheric Environment vol 31 no22 pp 3693ndash3706 1997
[41] S C Whalen ldquoInfluence of N and non-N salts on atmosphericmethane oxidation by upland boreal forest and tundra soilsrdquoBiology and Fertility of Soils vol 31 no 3-4 pp 279ndash287 2000
[42] J P Megonigal and A B Guenther ldquoMethane emissions fromupland forest soils and vegetationrdquo Tree Physiology vol 28 no4 pp 491ndash498 2008
[43] E A Davidson F Y Ishida and D C Nepstad ldquoEffects ofan experimental drought on soil emissions of carbon dioxidemethane nitrous oxide and nitric oxide in a moist tropicalforestrdquo Global Change Biology vol 10 no 5 pp 718ndash730 2004
[44] F LWang and J R Bettany ldquoMethane emission fromCanadianprairie and forest soils under short term flooding conditionsrdquoNutrient Cycling in Agroecosystems vol 49 no 1ndash3 pp 197ndash2021997
[45] R BrummeandWBorken ldquoSite variation inmethane oxidationas affected by atmospheric deposition and type of temperateforest ecosystemrdquo Global Biogeochemical Cycles vol 13 no 2pp 493ndash501 1999
[46] A P S Adamsen and G M King ldquoMethane consumption intemperate and subarctic forest soils rates vertical zonation andresponses to water and nitrogenrdquo Applied and EnvironmentalMicrobiology vol 59 no 2 pp 485ndash490 1993
[47] M S Castro P A Steudler J M Melillo J D Aber and R DBowden ldquoFactors controlling atmospheric methane consump-tion by temperate forest soilsrdquoGlobal Biogeochemical Cycles vol9 no 1 pp 1ndash10 1995
[48] B C Ball K A Smith L Klemedtsson et al ldquoThe influence ofsoil gas transport properties onmethane oxidation in a selectionof northern European soilsrdquo Journal of Geophysical Research Dvol 102 no 19 pp 23309ndash23317 1997
[49] K A Smith T Ball F Conen K E Dobbie J Masshederand A Rey ldquoExchange of greenhouse gases between soil andatmosphere interactions of soil physical factors and biologicalprocessesrdquo European Journal of Soil Science vol 54 no 4 pp779ndash791 2003
[50] H Feng G Cheng and L An ldquoMicrobial-mediated methanecycle in soils and global change a reviewrdquo Journal of Glaciologyand Geocryology vol 26 no 4 pp 411ndash419 2006 (Chinese)
[51] Y YanDWang and J Zheng ldquoAdvances in effects of biochar onthe soil N
2O and CH
4emissionsrdquo Chinese Agricultural Science
Bulletin vol 29 no 8 pp 140ndash146 2013 (Chinese)[52] OCetin andL Bilgel ldquoEffects of different irrigationmethods on
shedding and yield of cottonrdquo Agricultural Water Managementvol 54 no 1 pp 1ndash15 2002
[53] NDagdelenaH Basalb E Yılmaza T Gurbuza and S AkcayaldquoDifferent drip irrigation regimes affect cotton yield water useefficiency and fiber quality in western Turkeyrdquo AgriculturalWater Management vol 96 no 1 pp 110ndash120 2009
[54] N Ibragimov S R Evett Y Esanbekov B S Kamilov LMirzaev and J P A Lamers ldquoWater use efficiency of irrigatedcotton in Uzbekistan under drip and furrow irrigationrdquo Agri-cultural Water Management vol 90 no 1-2 pp 112ndash120 2007
[55] C R Camp P J Bauer and P G Hunt ldquoSubsurface dripirrigation lateral spacing and management for cotton in thesoutheastern Coastal plainrdquo Transactions of the American Soci-ety of Agricultural Engineers vol 40 no 4 pp 993ndash999 1997
Submit your manuscripts athttpwwwhindawicom
Nutrition and Metabolism
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Food ScienceInternational Journal of
Agronomy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom
Applied ampEnvironmentalSoil Science
Volume 2014
AgricultureAdvances in
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PsycheHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BiodiversityInternational Journal of
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ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
GenomicsInternational Journal of
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Plant GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biotechnology Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Forestry ResearchInternational Journal of
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Journal of BotanyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Cell BiologyInternational Journal of
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Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
6 The Scientific World Journal
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 10
100
200
300
400
FCDC
FBDB
N2O
(120583g m
minus2
hminus1)
(a)
Seedling stage Bud stage Flowering and boll-forming stage
Boll opening 0
30
60
90
120
FCDC
FBDB
stage
N2O
(120583g m
minus2
hminus1)
(b)
Figure 4 Effects of different irrigation methods and fertilization regimes on N2O flux rates during cotton growing season
May 1 Jun 1 Jul 1 Aug 1 Sep 1 Oct 1
0
5
10
CH4
(mg m
minus2
hminus1)
minus5
minus10
FCDC
FBDB
(a)
Seedling stage Bud stage Flowering and boll-forming stage
Boll opening
00
15
30
minus15
minus30
stage
CH4
(mg m
minus2
hminus1)
FCDC
FBDB
(b)
Figure 5 Effects of different irrigation methods and fertilization regimes on CH4flux rates during cotton growing season
[6] but higher than the N2O emissions from semiarid cotton
field in Pakistan [5] The variance in N2O emission among
different ecosites might be attributed to the difference in Nfertilizer application rate irrigation climate factors and soilproperties [28ndash33] Here lower level of N
2O emission from
cotton field was found under FB DC and DB in relation toFC with a high N fertilizer application rate (300 kgNhaminus1)(Table 4)The relatively lowerN
2Oemission from cotton field
under drip irrigation treatments was mainly attributed to thewater supply regime and N fertilizer dressing method (so-called fertigation) in drip irrigation system which favoreddecrease in N
2O emission In detail the soil moisture was
lower in cotton field with drip irrigation treatments than thatwith FC during the bud stage which was the main fertiliza-tion time of FC Previous studies reported that soilmoisture isa key factor in regulation of N
2O emission from agricultural
soil For instance theN2Oemissionwas enhanced alongwith
increased soil moisture in a given range due to the improveddenitrification [34ndash36] Therefore the relatively lower soilmoisture in cotton field withDC andDB during the bud stagecould reduce the N
2O emission more effectively than that
with FC Furthermore the decreased N fertilizer was directly
fertigated to the rhizosphere of cotton plants in drip irrigationtreatments with more times but less application rate pertimeThis N fertilizer dressing method could also improve Nuptake of cotton plant but decrease the soil inorganic N pool(NO3
minus-N and NH4
+-N) (Table 2) and hence reduce N sourceforN2Oemission whichwas significantly correlatedwith soil
N [37] However the observed reduction in N2O emission
caused by drip irrigationwas less than that in previous studiesconducted in the melon and tomato fields [8ndash10] This mightbe related to higher N fertilizer application rate in this study(300 kgNhaminus1) suggesting that the mitigation effect of dripirrigation onN
2Omay be depressed with a higher N fertilizer
application rateAlthough FB and FC used the same irrigation system
FB showed lower N2O emission than FC for the addition of
biochar A similar result was found in wheat field [14 15]However the effect of biochar on N
2O emissions under DB
and DC was covered up by the effect of drip irrigationBiochar had been shown to efficiently retain NH
4
+ via cationexchange by its developed specific surface area and surfacenegative charge density [38] Then the retained N wouldbe slowly released for plant growth thus biochar could
The Scientific World Journal 7
FC DC FB DB
0
500
1000
1500G
WP
(kg
CO2
eqha
minus1)
minus500
CH4
N2O
(a) Overall GWP
FC DC FB DB0
100
200
300
400
500
Yiel
d-sc
aled
GW
P (k
gCO
2eq
haminus1)
(b) Yield-scaled GWP
Figure 6 Overall GWP of GHGs (a) and yield-scaled GWP (b) for different treatmentsThe error bar in (a) was the standard error of overallGWP of N
2O and CH
4emissions
Table 2 Effects of different irrigation methods and fertilization regimes on major soil characteristics Values are means plusmn standard deviationof three replicates Different small letters in the same column refer to significant difference between treatments at 119875 lt 005 level
Seedling stage Bud stage Flowering and boll-forming stage Boll opening stageSoil moisture ()
FC 1679 plusmn 037b 1863 plusmn 025a 2046 plusmn 104a 1600 plusmn 125bDC 1728 plusmn 005b 1224 plusmn 013c 1979 plusmn 100a 1881 plusmn 113aFB 1819 plusmn 035ab 1892 plusmn 035a 1952 plusmn 085a 1416 plusmn 150bDB 1965 plusmn 071a 1493 plusmn 069b 2311 plusmn 082a 1870 plusmn 156a
Soil temperature (∘C)FC 2401 plusmn 033a 2455 plusmn 012b 212 plusmn 012b 1853 plusmn 010aDC 2398 plusmn 012a 2629 plusmn 025a 2255 plusmn 015a 1829 plusmn 027aFB 2428 plusmn 019a 2441 plusmn 036b 2178 plusmn 037ab 1803 plusmn 037aDB 2392 plusmn 009a 2580 plusmn 037a 2211 plusmn 033ab 1800 plusmn 005a
Soil NO3
minus-N (mg kgminus1)FC 10082 plusmn 403a 14582 plusmn 352a 5638 plusmn 668b 2694 plusmn 418aDC 10844 plusmn 339a 1980 plusmn 144b 4611 plusmn 129b 3877 plusmn 515aFB 9824 plusmn 686a 15594 plusmn 1238a 7694 plusmn 249a 3726 plusmn 012aDB 10475 plusmn 531a 2554 plusmn 080b 4113 plusmn 490b 3919 plusmn 645a
Soil NO4
+-N (mg kgminus1)FC 214 plusmn 028a 198 plusmn 041ab 138 plusmn 019a 046 plusmn 008aDC 214 plusmn 021a 107 plusmn 013b 096 plusmn 001a 036 plusmn 008aFB 217 plusmn 005a 229 plusmn 016a 124 plusmn 024a 034 plusmn 005aDB 204 plusmn 011a 129 plusmn 006b 101 plusmn 012a 057 plusmn 016a
Table 3 Effects of different irrigationmethods and fertilization regimes on cotton yield and water use efficiency Values are means plusmn standarddeviation of three replicates Different small letters in the same column refer to significant difference between treatments at 119875 lt 005 level
FC DC FB DBCotton yield (Mg haminus1) 176 plusmn 016a 202 plusmn 010a 194 plusmn 017a 211 plusmn 014aWater use efficiency (kgmminus3) 029 plusmn 003b 045 plusmn 002a 032 plusmn 003b 047 plusmn 003a
8 The Scientific World Journal
Table 4 Effects of different irrigation methods and fertilizationregimes on accumulated N2O and CH4 emissions during cottongrowing season Values are means plusmn standard deviation of threereplicates Different small letters in the same column refer tosignificant difference between treatments at 119875 lt 005 level
N2O (kg haminus1) CH4 (kg haminus1)
FC 171 plusmn 013a minus292 plusmn 096abDC 109 plusmn 011b minus887 plusmn 185bFB 121 plusmn 007b 539 plusmn 491aDB 104 plusmn 006b minus684 plusmn 107b
coordinate the mineral N availability and plant uptake Thiswould reduce the amount of N available for denitrificationand lost as N
2O [18] On the other hand decreases in
emissions of N2O in soil amended with biochar might be
attributed to improved aeration and porosity for its developedmicrostructure which might lead to lower denitrificationrates and alter the N
2O-to-N
2ratio during denitrification
[16]The present study indicated that the arid cotton fields
under FC DC and DB were the sinks of CH4 while FB was
the source of CH4 This was consistent with the results of
previous studies with different irrigation methods conductedin upland field [39ndash41] However drip irrigation was asource of CH
4in the study in cotton field [22] which was
inconsistent with the present results This might be relatedto the different rate of irrigation and fertilization Uplandfields are normally net sinks for CH
4 since the consumption
exceeds the production in CH4[42] The dry soil in upland
field limited the CH4emission however it did have a
possibility to become a source after rainfall within severaldays orweeks [43 44] Comparing theCH
4emission between
DC and FC it was shown that DC increased the uptakeof CH
4for the relative lower soil moisture in most of the
time during cotton growing season (Figure 2(a)) The mainfactor affectingCH
4uptake in summerwas soilmoisture [45]
which plays a critical role inCH4consumption [46] Decrease
in soil moisture enhanced CH4oxidation through improving
CH4diffusion from atmosphere into soil pore spaces [47] and
through gas diffusivity to control microbial oxidation whichchanges inversely with soil moisture [48 49]
In our study the addition of biochar increased CH4
emissions by 2846 higher with FB than that with FC whilethe uptake of CH
4with DB was 229 lower than that with
DC The result was in good agreement with previous studythat biochar addition promoted CH
4emissions of the upland
soil [17] However other studies had reported that biocharamendment reduces CH
4emissions as compared with the
control [18 19] The inconsistence might be attributed to thesoil type agricultural management and biochar type On onehand the addition of biochar increased the substrate sup-ply and created a favorable environment for methanogenicactivity On the other hand the CH
4emission from acid
soil was usually much lower than that from neutral soil[50] Biochar addition could increase soil PH which was abenefit for methanogenic bacteria Furthermore increasedsoil aeration due to increased porosity could increase CH
4
diffusion Biochar might play a more important role underpaddy fields compared with straw returning directly whichwould increase CH
4emission obviously [51]
There was significant difference between drip irrigationtreatments and furrow irrigation treatments in the total GWPof N2O and CH
4emissions (119875 lt 001) while fertilization
regimes showed little effect (Figure 6) The average yield-scaledGWPwas 801 and 722 lowerwithDCandDB thanthat with FC indicating that drip irrigation couldmitigate theyield-scaled GHG emissions from cotton field In previousstudies cotton yield was higher with drip irrigation thanthat with furrow irrigation [52] which agreed with ourstudy Although the difference of cotton yield between fourtreatments was insignificant WUE was significantly higherwith DC and DB than that with FC by 538 and 602respectively (119875 lt 005) (Table 3) WUE represented inthis study (from 0263 kgmminus3 to 0527 kgmminus3) were lowerthan that from the studies in Turkey where it rangedfrom 0508 kgmminus3 to 0648 kgmminus3 or from 076 kgmminus3 to146 kgmminus3 [52 53]The variance inWUE in different ecositescould be related to climate plant number varietal differencesand irrigation amount [54] It indicated that drip irrigationsignificantly increased WUE of cotton plants in relation tofurrow irrigation The relative higher WUE with DC and DBwas related to improved fertilizer efficiency and depressedleaching potential in drip irrigation system [55]
5 Conclusions
Irrigation methods significantly affected the GHG emissionsfrom cotton field in arid northwestern China Biochar addi-tion increased CH
4emissions and decreased N
2O emissions
The water supply and N fertilizer dressing method played akey role in regulating gas emissions Drip irrigation treat-ments (DC and DB) remarkably reduced GHG emissionscompared with furrow irrigation treatments (FC and FB) Inaddition drip irrigation treatments (DC and DB) had higheryield and WUE compared to furrow irrigation treatments(FC and FB) Thus mulched-drip irrigation with conven-tional fertilization or conventional fertilization + biocharshould be a better approach to increase cotton yield withdepressed GHG emissions in arid northwestern China
Abbreviations
GHG Greenhouse gasGWP Global warming potentialWUE Water use efficiency
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgment
This work was financially supported by the opened subjectof Xinjiang Key Laboratory of Water Cycle and Utilization inArid Zone (Grant no XJYS0907-2010-03)
The Scientific World Journal 9
References
[1] IPCC Climate Change 2007 The Physical Science Basis Cam-bridge University Press Cambridge UK 2007
[2] A F Bouwman L J M Boumans and N H Baffes GlobalEstimates of Gaseous Emissions of NH
3 NO and N
2O from
Agricultural Land Food and Agriculture Organisation RomeItaly 2001
[3] FAOSTAT 2002 httpfaostatfaoorg[4] C Liu X Zheng Z Zhou et al ldquoNitrous oxide and nitric oxide
emissions from an irrigated cotton field in Northern ChinardquoPlant and Soil vol 332 no 1-2 pp 123ndash134 2010
[5] TMahmood RAli J Iqbal andURobab ldquoNitrous oxide emis-sion from an irrigated cotton field under semiarid subtropicalconditionsrdquo Biology and Fertility of Soils vol 44 no 5 pp 773ndash781 2008
[6] C Scheer R Wassmann K Kienzler N Ibragimov andR Eschanov ldquoNitrous oxide emissions from fertilized irri-gated cotton (Gossypium hirsutum L) in the Aral Sea BasinUzbekistan influence of nitrogen applications and irrigationpracticesrdquo Soil Biology and Biochemistry vol 40 no 2 pp 290ndash301 2008
[7] J Li J Zhang and L Ren ldquoWater and nitrogen distributionas affected by fertigation of ammonium nitrate from a pointsourcerdquo Irrigation Science vol 22 no 1 pp 19ndash30 2003
[8] C M Kallenbach D E Rolston and W R Horwath ldquoCovercropping affects soil N
2O and CO
2emissions differently
depending on type of irrigationrdquo Agriculture Ecosystems andEnvironment vol 137 no 3-4 pp 251ndash260 2010
[9] L Sanchez-Martın A Arce A Benito L Garcia-Torres andA Vallejo ldquoInfluence of drip and furrow irrigation systems onnitrogen oxide emissions from a horticultural croprdquo Soil Biologyand Biochemistry vol 40 no 7 pp 1698ndash1706 2008
[10] L Sanchez-Martın A Meijide L Garcia-Torres and A VallejoldquoCombination of drip irrigation and organic fertilizer formitigating emissions of nitrogen oxides in semiarid climaterdquoAgriculture Ecosystems and Environment vol 137 no 1-2 pp99ndash107 2010
[11] J Lehmann ldquoBio-energy in the blackrdquo Frontiers in Ecology andthe Environment vol 5 no 7 pp 381ndash387 2007
[12] M Fowles ldquoBlack carbon sequestration as an alternative tobioenergyrdquo Biomass and Bioenergy vol 31 no 6 pp 426ndash4322007
[13] M Rondon J A Ramirez and J Lehmann ldquoCharcoal additionsreduce net emissions of greenhouse gases to the atmosphererdquo inProceedings of the 3rd USDA Symposium on Greenhouse Gasesand Carbon Sequestration p 208 Baltimore Md USA March2005
[14] A Aguilar-Chavez M Dıaz-Rojas M del Rosario Cardenas-Aquino L Dendooven and M Luna-Guido ldquoGreenhouse gasemissions from a wastewater sludge-amended soil cultivatedwith wheat (Triticum spp L) as affected by different applicationrates of charcoalrdquo Soil Biology and Biochemistry vol 52 pp 90ndash95 2012
[15] S Castaldi M Riondino S Baronti et al ldquoImpact of biocharapplication to a Mediterranean wheat crop on soil microbialactivity and greenhouse gas fluxesrdquo Chemosphere vol 85 no9 pp 1464ndash1471 2011
[16] B P Singh B J Hatton B Singh A L Cowie and A KathurialdquoInfluence of biochars on nitrous oxide emission and nitrogenleaching from two contrasting soilsrdquo Journal of EnvironmentalQuality vol 39 no 4 pp 1224ndash1235 2010
[17] J Wang X Pan Y Liu X Zhang and Z Xiong ldquoEffects ofbiochar amendment in two soils on greenhouse gas emissionsand crop productionrdquo Plant and Soil vol 360 no 1-2 pp 287ndash298 2012
[18] K Karhu T Mattila I Bergstrom and K Regina ldquoBiocharaddition to agricultural soil increased CH
4uptake and water
holding capacitymdashresults from a short-term pilot field studyrdquoAgriculture Ecosystems and Environment vol 140 no 1-2 pp309ndash313 2011
[19] C Scheer P R Grace D W Rowlings S Kimber and L vanZwieten ldquoEffect of biochar amendment on the soil-atmosphereexchange of greenhouse gases from an intensive subtropicalpasture in northernNew SouthWales AustraliardquoPlant and Soilvol 345 no 1 pp 47ndash58 2011
[20] Z Li R Zhang X Wang J Wang C Zhang and C TianldquoCarbon dioxide fluxes and concentrations in a cotton fieldin northwestern China effects of plastic mulching and dripirrigationrdquo Pedosphere vol 21 no 2 pp 178ndash185 2011
[21] Q Zhang L Yang J Wang H Luo Y Zhang and WZhang ldquoEffects of different irrigation methods and fertilizationmeasures on soil respiration and its component contribution incotton field in arid regionrdquo Scientia Agricultura Sinica vol 25no 12 pp 2420ndash2430 2012 (Chinese)
[22] Z Li R Zhang X Wang F Chen D Lai and C Tian ldquoEffectsof plastic film mulching with drip irrigation on N
2O and CH
4
emissions fromcotton fields in arid landrdquo Journal of AgriculturalScience 2013
[23] FAOIAEA Measurement of Methane and Nitrous Oxide Emis-sion from Agriculture A Joint Undertakong by the Food andAgriculture Organization of United Nations and InternationalAtomic Energy Agency International Atomic Energy AgencyVienna Austria 1992
[24] Y Huang J Jiang L Zong Q Zhou R L Sass and F MFisher ldquoInfluence of planting density and precipitation on N
2O
emission from a winter wheat fieldrdquo Environmental Science vol22 no 6 pp 20ndash23 2001 (Chinese)
[25] G C Topp J L Davis and A P Annan ldquoElectromagneticdetermination of soil water content measurements in coaxialtransmission linesrdquoWater Resources Research vol 16 no 3 pp574ndash582 1980
[26] R Lu Soil Agricultural Chemistry Analytical Method ChinaAgricultural Science and Technology Press Beijing China2000
[27] L Zhou F Li S Jin and Y Song ldquoHow two ridges andthe furrow mulched with plastic film affect soil water soiltemperature and yield of maize on the semiarid Loess Plateauof Chinardquo Field Crops Research vol 113 no 1 pp 41ndash47 2009
[28] J Clemens M P Schillinger H Goldbach and B HuweldquoSpatial variability of N
2O emissions and soil parameters of an
arable silt loammdasha field studyrdquo Biology and Fertility of Soils vol28 no 4 pp 403ndash406 1999
[29] K InubushiM A Barahona andK Yamakawa ldquoEffects of saltsand moisture content on N
2O emission and nitrogen dynamics
in Yellow soil and Andosol in model experimentsrdquo Biology andFertility of Soils vol 29 no 4 pp 401ndash407 1999
[30] B J Joslashrgensen and R N Joslashrgensen ldquoField-scale and laboratorystudy of factors affecting N
2O emissions from a rye stubble field
on sandy loam soilrdquo Biology and Fertility of Soils vol 25 no 4pp 366ndash371 1997
[31] A R Mosier and Z Zhu ldquoChanges in patterns of fertilizernitrogen use in Asia and its consequences for N
2O emissions
10 The Scientific World Journal
from agricultural systemsrdquo Nutrient Cycling in Agroecosystemsvol 57 no 1 pp 107ndash117 2000
[32] R Ruser H Flessa R Schilling F Beese and J C MunchldquoEffect of crop-specific field management and N fertilizationon N2O emissions from a fine-loamy soilrdquo Nutrient Cycling in
Agroecosystems vol 59 no 2 pp 177ndash191 2001[33] C Song and J Zhang ldquoEffects of soil moisture temperature
and nitrogen fertilization on soil respiration and nitrous oxideemission duringmaize growth period in northeast ChinardquoActaAgriculturae Scandinavica B Soil and Plant Science vol 59 no2 pp 97ndash106 2009
[34] D M Linn and J W Doran ldquoEffect of water-filled pore spaceon carbon dioxide and nitrous oxide production in tilled andnontilled soilsrdquo Soil Science Society of America Journal vol 48no 6 pp 1267ndash1272 1984
[35] X J Liu A R Mosier A D Halvorson C A Reule andF S Zhang ldquoDinitrogen and N
2O emissions in arable soils
effect of tillage N source and soil moisturerdquo Soil Biology andBiochemistry vol 39 no 9 pp 2362ndash2370 2007
[36] L Sanchez-Martın A Vallejo J Dick and U M Skiba ldquoTheinfluence of soluble carbon and fertilizer nitrogen on nitricoxide and nitrous oxide emissions from two contrasting agri-cultural soilsrdquo Soil Biology and Biochemistry vol 40 no 1 pp142ndash151 2008
[37] Z Mu S D Kimura Y Toma and R Hatano ldquoNitrous oxidefluxes from upland soils in central Hokkaido Japanrdquo Journal ofEnvironmental Sciences vol 20 no 11 pp 1312ndash1322 2008
[38] B Liang J Lehmann D Solomon et al ldquoBlack carbon increasescation exchange capacity in soilsrdquo Soil Science Society of AmericaJournal vol 70 no 5 pp 1719ndash1730 2006
[39] P Boeckx and O Van Cleemput ldquoEstimates of N2O and CH
4
fluxes from agricultural lands in various regions in EuroperdquoNutrient Cycling in Agroecosystems vol 60 no 1ndash3 pp 35ndash472001
[40] J A MacDonald U Skiba L J Sheppard et al ldquoThe effectof nitrogen deposition and seasonal variability on methaneoxidation and nitrous oxide emission rates in an upland spruceplantation andmoorlandrdquoAtmospheric Environment vol 31 no22 pp 3693ndash3706 1997
[41] S C Whalen ldquoInfluence of N and non-N salts on atmosphericmethane oxidation by upland boreal forest and tundra soilsrdquoBiology and Fertility of Soils vol 31 no 3-4 pp 279ndash287 2000
[42] J P Megonigal and A B Guenther ldquoMethane emissions fromupland forest soils and vegetationrdquo Tree Physiology vol 28 no4 pp 491ndash498 2008
[43] E A Davidson F Y Ishida and D C Nepstad ldquoEffects ofan experimental drought on soil emissions of carbon dioxidemethane nitrous oxide and nitric oxide in a moist tropicalforestrdquo Global Change Biology vol 10 no 5 pp 718ndash730 2004
[44] F LWang and J R Bettany ldquoMethane emission fromCanadianprairie and forest soils under short term flooding conditionsrdquoNutrient Cycling in Agroecosystems vol 49 no 1ndash3 pp 197ndash2021997
[45] R BrummeandWBorken ldquoSite variation inmethane oxidationas affected by atmospheric deposition and type of temperateforest ecosystemrdquo Global Biogeochemical Cycles vol 13 no 2pp 493ndash501 1999
[46] A P S Adamsen and G M King ldquoMethane consumption intemperate and subarctic forest soils rates vertical zonation andresponses to water and nitrogenrdquo Applied and EnvironmentalMicrobiology vol 59 no 2 pp 485ndash490 1993
[47] M S Castro P A Steudler J M Melillo J D Aber and R DBowden ldquoFactors controlling atmospheric methane consump-tion by temperate forest soilsrdquoGlobal Biogeochemical Cycles vol9 no 1 pp 1ndash10 1995
[48] B C Ball K A Smith L Klemedtsson et al ldquoThe influence ofsoil gas transport properties onmethane oxidation in a selectionof northern European soilsrdquo Journal of Geophysical Research Dvol 102 no 19 pp 23309ndash23317 1997
[49] K A Smith T Ball F Conen K E Dobbie J Masshederand A Rey ldquoExchange of greenhouse gases between soil andatmosphere interactions of soil physical factors and biologicalprocessesrdquo European Journal of Soil Science vol 54 no 4 pp779ndash791 2003
[50] H Feng G Cheng and L An ldquoMicrobial-mediated methanecycle in soils and global change a reviewrdquo Journal of Glaciologyand Geocryology vol 26 no 4 pp 411ndash419 2006 (Chinese)
[51] Y YanDWang and J Zheng ldquoAdvances in effects of biochar onthe soil N
2O and CH
4emissionsrdquo Chinese Agricultural Science
Bulletin vol 29 no 8 pp 140ndash146 2013 (Chinese)[52] OCetin andL Bilgel ldquoEffects of different irrigationmethods on
shedding and yield of cottonrdquo Agricultural Water Managementvol 54 no 1 pp 1ndash15 2002
[53] NDagdelenaH Basalb E Yılmaza T Gurbuza and S AkcayaldquoDifferent drip irrigation regimes affect cotton yield water useefficiency and fiber quality in western Turkeyrdquo AgriculturalWater Management vol 96 no 1 pp 110ndash120 2009
[54] N Ibragimov S R Evett Y Esanbekov B S Kamilov LMirzaev and J P A Lamers ldquoWater use efficiency of irrigatedcotton in Uzbekistan under drip and furrow irrigationrdquo Agri-cultural Water Management vol 90 no 1-2 pp 112ndash120 2007
[55] C R Camp P J Bauer and P G Hunt ldquoSubsurface dripirrigation lateral spacing and management for cotton in thesoutheastern Coastal plainrdquo Transactions of the American Soci-ety of Agricultural Engineers vol 40 no 4 pp 993ndash999 1997
Submit your manuscripts athttpwwwhindawicom
Nutrition and Metabolism
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Food ScienceInternational Journal of
Agronomy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom
Applied ampEnvironmentalSoil Science
Volume 2014
AgricultureAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
PsycheHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BiodiversityInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Plant GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biotechnology Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Forestry ResearchInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of BotanyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
EcologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Veterinary Medicine International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Cell BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World Journal 7
FC DC FB DB
0
500
1000
1500G
WP
(kg
CO2
eqha
minus1)
minus500
CH4
N2O
(a) Overall GWP
FC DC FB DB0
100
200
300
400
500
Yiel
d-sc
aled
GW
P (k
gCO
2eq
haminus1)
(b) Yield-scaled GWP
Figure 6 Overall GWP of GHGs (a) and yield-scaled GWP (b) for different treatmentsThe error bar in (a) was the standard error of overallGWP of N
2O and CH
4emissions
Table 2 Effects of different irrigation methods and fertilization regimes on major soil characteristics Values are means plusmn standard deviationof three replicates Different small letters in the same column refer to significant difference between treatments at 119875 lt 005 level
Seedling stage Bud stage Flowering and boll-forming stage Boll opening stageSoil moisture ()
FC 1679 plusmn 037b 1863 plusmn 025a 2046 plusmn 104a 1600 plusmn 125bDC 1728 plusmn 005b 1224 plusmn 013c 1979 plusmn 100a 1881 plusmn 113aFB 1819 plusmn 035ab 1892 plusmn 035a 1952 plusmn 085a 1416 plusmn 150bDB 1965 plusmn 071a 1493 plusmn 069b 2311 plusmn 082a 1870 plusmn 156a
Soil temperature (∘C)FC 2401 plusmn 033a 2455 plusmn 012b 212 plusmn 012b 1853 plusmn 010aDC 2398 plusmn 012a 2629 plusmn 025a 2255 plusmn 015a 1829 plusmn 027aFB 2428 plusmn 019a 2441 plusmn 036b 2178 plusmn 037ab 1803 plusmn 037aDB 2392 plusmn 009a 2580 plusmn 037a 2211 plusmn 033ab 1800 plusmn 005a
Soil NO3
minus-N (mg kgminus1)FC 10082 plusmn 403a 14582 plusmn 352a 5638 plusmn 668b 2694 plusmn 418aDC 10844 plusmn 339a 1980 plusmn 144b 4611 plusmn 129b 3877 plusmn 515aFB 9824 plusmn 686a 15594 plusmn 1238a 7694 plusmn 249a 3726 plusmn 012aDB 10475 plusmn 531a 2554 plusmn 080b 4113 plusmn 490b 3919 plusmn 645a
Soil NO4
+-N (mg kgminus1)FC 214 plusmn 028a 198 plusmn 041ab 138 plusmn 019a 046 plusmn 008aDC 214 plusmn 021a 107 plusmn 013b 096 plusmn 001a 036 plusmn 008aFB 217 plusmn 005a 229 plusmn 016a 124 plusmn 024a 034 plusmn 005aDB 204 plusmn 011a 129 plusmn 006b 101 plusmn 012a 057 plusmn 016a
Table 3 Effects of different irrigationmethods and fertilization regimes on cotton yield and water use efficiency Values are means plusmn standarddeviation of three replicates Different small letters in the same column refer to significant difference between treatments at 119875 lt 005 level
FC DC FB DBCotton yield (Mg haminus1) 176 plusmn 016a 202 plusmn 010a 194 plusmn 017a 211 plusmn 014aWater use efficiency (kgmminus3) 029 plusmn 003b 045 plusmn 002a 032 plusmn 003b 047 plusmn 003a
8 The Scientific World Journal
Table 4 Effects of different irrigation methods and fertilizationregimes on accumulated N2O and CH4 emissions during cottongrowing season Values are means plusmn standard deviation of threereplicates Different small letters in the same column refer tosignificant difference between treatments at 119875 lt 005 level
N2O (kg haminus1) CH4 (kg haminus1)
FC 171 plusmn 013a minus292 plusmn 096abDC 109 plusmn 011b minus887 plusmn 185bFB 121 plusmn 007b 539 plusmn 491aDB 104 plusmn 006b minus684 plusmn 107b
coordinate the mineral N availability and plant uptake Thiswould reduce the amount of N available for denitrificationand lost as N
2O [18] On the other hand decreases in
emissions of N2O in soil amended with biochar might be
attributed to improved aeration and porosity for its developedmicrostructure which might lead to lower denitrificationrates and alter the N
2O-to-N
2ratio during denitrification
[16]The present study indicated that the arid cotton fields
under FC DC and DB were the sinks of CH4 while FB was
the source of CH4 This was consistent with the results of
previous studies with different irrigation methods conductedin upland field [39ndash41] However drip irrigation was asource of CH
4in the study in cotton field [22] which was
inconsistent with the present results This might be relatedto the different rate of irrigation and fertilization Uplandfields are normally net sinks for CH
4 since the consumption
exceeds the production in CH4[42] The dry soil in upland
field limited the CH4emission however it did have a
possibility to become a source after rainfall within severaldays orweeks [43 44] Comparing theCH
4emission between
DC and FC it was shown that DC increased the uptakeof CH
4for the relative lower soil moisture in most of the
time during cotton growing season (Figure 2(a)) The mainfactor affectingCH
4uptake in summerwas soilmoisture [45]
which plays a critical role inCH4consumption [46] Decrease
in soil moisture enhanced CH4oxidation through improving
CH4diffusion from atmosphere into soil pore spaces [47] and
through gas diffusivity to control microbial oxidation whichchanges inversely with soil moisture [48 49]
In our study the addition of biochar increased CH4
emissions by 2846 higher with FB than that with FC whilethe uptake of CH
4with DB was 229 lower than that with
DC The result was in good agreement with previous studythat biochar addition promoted CH
4emissions of the upland
soil [17] However other studies had reported that biocharamendment reduces CH
4emissions as compared with the
control [18 19] The inconsistence might be attributed to thesoil type agricultural management and biochar type On onehand the addition of biochar increased the substrate sup-ply and created a favorable environment for methanogenicactivity On the other hand the CH
4emission from acid
soil was usually much lower than that from neutral soil[50] Biochar addition could increase soil PH which was abenefit for methanogenic bacteria Furthermore increasedsoil aeration due to increased porosity could increase CH
4
diffusion Biochar might play a more important role underpaddy fields compared with straw returning directly whichwould increase CH
4emission obviously [51]
There was significant difference between drip irrigationtreatments and furrow irrigation treatments in the total GWPof N2O and CH
4emissions (119875 lt 001) while fertilization
regimes showed little effect (Figure 6) The average yield-scaledGWPwas 801 and 722 lowerwithDCandDB thanthat with FC indicating that drip irrigation couldmitigate theyield-scaled GHG emissions from cotton field In previousstudies cotton yield was higher with drip irrigation thanthat with furrow irrigation [52] which agreed with ourstudy Although the difference of cotton yield between fourtreatments was insignificant WUE was significantly higherwith DC and DB than that with FC by 538 and 602respectively (119875 lt 005) (Table 3) WUE represented inthis study (from 0263 kgmminus3 to 0527 kgmminus3) were lowerthan that from the studies in Turkey where it rangedfrom 0508 kgmminus3 to 0648 kgmminus3 or from 076 kgmminus3 to146 kgmminus3 [52 53]The variance inWUE in different ecositescould be related to climate plant number varietal differencesand irrigation amount [54] It indicated that drip irrigationsignificantly increased WUE of cotton plants in relation tofurrow irrigation The relative higher WUE with DC and DBwas related to improved fertilizer efficiency and depressedleaching potential in drip irrigation system [55]
5 Conclusions
Irrigation methods significantly affected the GHG emissionsfrom cotton field in arid northwestern China Biochar addi-tion increased CH
4emissions and decreased N
2O emissions
The water supply and N fertilizer dressing method played akey role in regulating gas emissions Drip irrigation treat-ments (DC and DB) remarkably reduced GHG emissionscompared with furrow irrigation treatments (FC and FB) Inaddition drip irrigation treatments (DC and DB) had higheryield and WUE compared to furrow irrigation treatments(FC and FB) Thus mulched-drip irrigation with conven-tional fertilization or conventional fertilization + biocharshould be a better approach to increase cotton yield withdepressed GHG emissions in arid northwestern China
Abbreviations
GHG Greenhouse gasGWP Global warming potentialWUE Water use efficiency
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgment
This work was financially supported by the opened subjectof Xinjiang Key Laboratory of Water Cycle and Utilization inArid Zone (Grant no XJYS0907-2010-03)
The Scientific World Journal 9
References
[1] IPCC Climate Change 2007 The Physical Science Basis Cam-bridge University Press Cambridge UK 2007
[2] A F Bouwman L J M Boumans and N H Baffes GlobalEstimates of Gaseous Emissions of NH
3 NO and N
2O from
Agricultural Land Food and Agriculture Organisation RomeItaly 2001
[3] FAOSTAT 2002 httpfaostatfaoorg[4] C Liu X Zheng Z Zhou et al ldquoNitrous oxide and nitric oxide
emissions from an irrigated cotton field in Northern ChinardquoPlant and Soil vol 332 no 1-2 pp 123ndash134 2010
[5] TMahmood RAli J Iqbal andURobab ldquoNitrous oxide emis-sion from an irrigated cotton field under semiarid subtropicalconditionsrdquo Biology and Fertility of Soils vol 44 no 5 pp 773ndash781 2008
[6] C Scheer R Wassmann K Kienzler N Ibragimov andR Eschanov ldquoNitrous oxide emissions from fertilized irri-gated cotton (Gossypium hirsutum L) in the Aral Sea BasinUzbekistan influence of nitrogen applications and irrigationpracticesrdquo Soil Biology and Biochemistry vol 40 no 2 pp 290ndash301 2008
[7] J Li J Zhang and L Ren ldquoWater and nitrogen distributionas affected by fertigation of ammonium nitrate from a pointsourcerdquo Irrigation Science vol 22 no 1 pp 19ndash30 2003
[8] C M Kallenbach D E Rolston and W R Horwath ldquoCovercropping affects soil N
2O and CO
2emissions differently
depending on type of irrigationrdquo Agriculture Ecosystems andEnvironment vol 137 no 3-4 pp 251ndash260 2010
[9] L Sanchez-Martın A Arce A Benito L Garcia-Torres andA Vallejo ldquoInfluence of drip and furrow irrigation systems onnitrogen oxide emissions from a horticultural croprdquo Soil Biologyand Biochemistry vol 40 no 7 pp 1698ndash1706 2008
[10] L Sanchez-Martın A Meijide L Garcia-Torres and A VallejoldquoCombination of drip irrigation and organic fertilizer formitigating emissions of nitrogen oxides in semiarid climaterdquoAgriculture Ecosystems and Environment vol 137 no 1-2 pp99ndash107 2010
[11] J Lehmann ldquoBio-energy in the blackrdquo Frontiers in Ecology andthe Environment vol 5 no 7 pp 381ndash387 2007
[12] M Fowles ldquoBlack carbon sequestration as an alternative tobioenergyrdquo Biomass and Bioenergy vol 31 no 6 pp 426ndash4322007
[13] M Rondon J A Ramirez and J Lehmann ldquoCharcoal additionsreduce net emissions of greenhouse gases to the atmosphererdquo inProceedings of the 3rd USDA Symposium on Greenhouse Gasesand Carbon Sequestration p 208 Baltimore Md USA March2005
[14] A Aguilar-Chavez M Dıaz-Rojas M del Rosario Cardenas-Aquino L Dendooven and M Luna-Guido ldquoGreenhouse gasemissions from a wastewater sludge-amended soil cultivatedwith wheat (Triticum spp L) as affected by different applicationrates of charcoalrdquo Soil Biology and Biochemistry vol 52 pp 90ndash95 2012
[15] S Castaldi M Riondino S Baronti et al ldquoImpact of biocharapplication to a Mediterranean wheat crop on soil microbialactivity and greenhouse gas fluxesrdquo Chemosphere vol 85 no9 pp 1464ndash1471 2011
[16] B P Singh B J Hatton B Singh A L Cowie and A KathurialdquoInfluence of biochars on nitrous oxide emission and nitrogenleaching from two contrasting soilsrdquo Journal of EnvironmentalQuality vol 39 no 4 pp 1224ndash1235 2010
[17] J Wang X Pan Y Liu X Zhang and Z Xiong ldquoEffects ofbiochar amendment in two soils on greenhouse gas emissionsand crop productionrdquo Plant and Soil vol 360 no 1-2 pp 287ndash298 2012
[18] K Karhu T Mattila I Bergstrom and K Regina ldquoBiocharaddition to agricultural soil increased CH
4uptake and water
holding capacitymdashresults from a short-term pilot field studyrdquoAgriculture Ecosystems and Environment vol 140 no 1-2 pp309ndash313 2011
[19] C Scheer P R Grace D W Rowlings S Kimber and L vanZwieten ldquoEffect of biochar amendment on the soil-atmosphereexchange of greenhouse gases from an intensive subtropicalpasture in northernNew SouthWales AustraliardquoPlant and Soilvol 345 no 1 pp 47ndash58 2011
[20] Z Li R Zhang X Wang J Wang C Zhang and C TianldquoCarbon dioxide fluxes and concentrations in a cotton fieldin northwestern China effects of plastic mulching and dripirrigationrdquo Pedosphere vol 21 no 2 pp 178ndash185 2011
[21] Q Zhang L Yang J Wang H Luo Y Zhang and WZhang ldquoEffects of different irrigation methods and fertilizationmeasures on soil respiration and its component contribution incotton field in arid regionrdquo Scientia Agricultura Sinica vol 25no 12 pp 2420ndash2430 2012 (Chinese)
[22] Z Li R Zhang X Wang F Chen D Lai and C Tian ldquoEffectsof plastic film mulching with drip irrigation on N
2O and CH
4
emissions fromcotton fields in arid landrdquo Journal of AgriculturalScience 2013
[23] FAOIAEA Measurement of Methane and Nitrous Oxide Emis-sion from Agriculture A Joint Undertakong by the Food andAgriculture Organization of United Nations and InternationalAtomic Energy Agency International Atomic Energy AgencyVienna Austria 1992
[24] Y Huang J Jiang L Zong Q Zhou R L Sass and F MFisher ldquoInfluence of planting density and precipitation on N
2O
emission from a winter wheat fieldrdquo Environmental Science vol22 no 6 pp 20ndash23 2001 (Chinese)
[25] G C Topp J L Davis and A P Annan ldquoElectromagneticdetermination of soil water content measurements in coaxialtransmission linesrdquoWater Resources Research vol 16 no 3 pp574ndash582 1980
[26] R Lu Soil Agricultural Chemistry Analytical Method ChinaAgricultural Science and Technology Press Beijing China2000
[27] L Zhou F Li S Jin and Y Song ldquoHow two ridges andthe furrow mulched with plastic film affect soil water soiltemperature and yield of maize on the semiarid Loess Plateauof Chinardquo Field Crops Research vol 113 no 1 pp 41ndash47 2009
[28] J Clemens M P Schillinger H Goldbach and B HuweldquoSpatial variability of N
2O emissions and soil parameters of an
arable silt loammdasha field studyrdquo Biology and Fertility of Soils vol28 no 4 pp 403ndash406 1999
[29] K InubushiM A Barahona andK Yamakawa ldquoEffects of saltsand moisture content on N
2O emission and nitrogen dynamics
in Yellow soil and Andosol in model experimentsrdquo Biology andFertility of Soils vol 29 no 4 pp 401ndash407 1999
[30] B J Joslashrgensen and R N Joslashrgensen ldquoField-scale and laboratorystudy of factors affecting N
2O emissions from a rye stubble field
on sandy loam soilrdquo Biology and Fertility of Soils vol 25 no 4pp 366ndash371 1997
[31] A R Mosier and Z Zhu ldquoChanges in patterns of fertilizernitrogen use in Asia and its consequences for N
2O emissions
10 The Scientific World Journal
from agricultural systemsrdquo Nutrient Cycling in Agroecosystemsvol 57 no 1 pp 107ndash117 2000
[32] R Ruser H Flessa R Schilling F Beese and J C MunchldquoEffect of crop-specific field management and N fertilizationon N2O emissions from a fine-loamy soilrdquo Nutrient Cycling in
Agroecosystems vol 59 no 2 pp 177ndash191 2001[33] C Song and J Zhang ldquoEffects of soil moisture temperature
and nitrogen fertilization on soil respiration and nitrous oxideemission duringmaize growth period in northeast ChinardquoActaAgriculturae Scandinavica B Soil and Plant Science vol 59 no2 pp 97ndash106 2009
[34] D M Linn and J W Doran ldquoEffect of water-filled pore spaceon carbon dioxide and nitrous oxide production in tilled andnontilled soilsrdquo Soil Science Society of America Journal vol 48no 6 pp 1267ndash1272 1984
[35] X J Liu A R Mosier A D Halvorson C A Reule andF S Zhang ldquoDinitrogen and N
2O emissions in arable soils
effect of tillage N source and soil moisturerdquo Soil Biology andBiochemistry vol 39 no 9 pp 2362ndash2370 2007
[36] L Sanchez-Martın A Vallejo J Dick and U M Skiba ldquoTheinfluence of soluble carbon and fertilizer nitrogen on nitricoxide and nitrous oxide emissions from two contrasting agri-cultural soilsrdquo Soil Biology and Biochemistry vol 40 no 1 pp142ndash151 2008
[37] Z Mu S D Kimura Y Toma and R Hatano ldquoNitrous oxidefluxes from upland soils in central Hokkaido Japanrdquo Journal ofEnvironmental Sciences vol 20 no 11 pp 1312ndash1322 2008
[38] B Liang J Lehmann D Solomon et al ldquoBlack carbon increasescation exchange capacity in soilsrdquo Soil Science Society of AmericaJournal vol 70 no 5 pp 1719ndash1730 2006
[39] P Boeckx and O Van Cleemput ldquoEstimates of N2O and CH
4
fluxes from agricultural lands in various regions in EuroperdquoNutrient Cycling in Agroecosystems vol 60 no 1ndash3 pp 35ndash472001
[40] J A MacDonald U Skiba L J Sheppard et al ldquoThe effectof nitrogen deposition and seasonal variability on methaneoxidation and nitrous oxide emission rates in an upland spruceplantation andmoorlandrdquoAtmospheric Environment vol 31 no22 pp 3693ndash3706 1997
[41] S C Whalen ldquoInfluence of N and non-N salts on atmosphericmethane oxidation by upland boreal forest and tundra soilsrdquoBiology and Fertility of Soils vol 31 no 3-4 pp 279ndash287 2000
[42] J P Megonigal and A B Guenther ldquoMethane emissions fromupland forest soils and vegetationrdquo Tree Physiology vol 28 no4 pp 491ndash498 2008
[43] E A Davidson F Y Ishida and D C Nepstad ldquoEffects ofan experimental drought on soil emissions of carbon dioxidemethane nitrous oxide and nitric oxide in a moist tropicalforestrdquo Global Change Biology vol 10 no 5 pp 718ndash730 2004
[44] F LWang and J R Bettany ldquoMethane emission fromCanadianprairie and forest soils under short term flooding conditionsrdquoNutrient Cycling in Agroecosystems vol 49 no 1ndash3 pp 197ndash2021997
[45] R BrummeandWBorken ldquoSite variation inmethane oxidationas affected by atmospheric deposition and type of temperateforest ecosystemrdquo Global Biogeochemical Cycles vol 13 no 2pp 493ndash501 1999
[46] A P S Adamsen and G M King ldquoMethane consumption intemperate and subarctic forest soils rates vertical zonation andresponses to water and nitrogenrdquo Applied and EnvironmentalMicrobiology vol 59 no 2 pp 485ndash490 1993
[47] M S Castro P A Steudler J M Melillo J D Aber and R DBowden ldquoFactors controlling atmospheric methane consump-tion by temperate forest soilsrdquoGlobal Biogeochemical Cycles vol9 no 1 pp 1ndash10 1995
[48] B C Ball K A Smith L Klemedtsson et al ldquoThe influence ofsoil gas transport properties onmethane oxidation in a selectionof northern European soilsrdquo Journal of Geophysical Research Dvol 102 no 19 pp 23309ndash23317 1997
[49] K A Smith T Ball F Conen K E Dobbie J Masshederand A Rey ldquoExchange of greenhouse gases between soil andatmosphere interactions of soil physical factors and biologicalprocessesrdquo European Journal of Soil Science vol 54 no 4 pp779ndash791 2003
[50] H Feng G Cheng and L An ldquoMicrobial-mediated methanecycle in soils and global change a reviewrdquo Journal of Glaciologyand Geocryology vol 26 no 4 pp 411ndash419 2006 (Chinese)
[51] Y YanDWang and J Zheng ldquoAdvances in effects of biochar onthe soil N
2O and CH
4emissionsrdquo Chinese Agricultural Science
Bulletin vol 29 no 8 pp 140ndash146 2013 (Chinese)[52] OCetin andL Bilgel ldquoEffects of different irrigationmethods on
shedding and yield of cottonrdquo Agricultural Water Managementvol 54 no 1 pp 1ndash15 2002
[53] NDagdelenaH Basalb E Yılmaza T Gurbuza and S AkcayaldquoDifferent drip irrigation regimes affect cotton yield water useefficiency and fiber quality in western Turkeyrdquo AgriculturalWater Management vol 96 no 1 pp 110ndash120 2009
[54] N Ibragimov S R Evett Y Esanbekov B S Kamilov LMirzaev and J P A Lamers ldquoWater use efficiency of irrigatedcotton in Uzbekistan under drip and furrow irrigationrdquo Agri-cultural Water Management vol 90 no 1-2 pp 112ndash120 2007
[55] C R Camp P J Bauer and P G Hunt ldquoSubsurface dripirrigation lateral spacing and management for cotton in thesoutheastern Coastal plainrdquo Transactions of the American Soci-ety of Agricultural Engineers vol 40 no 4 pp 993ndash999 1997
Submit your manuscripts athttpwwwhindawicom
Nutrition and Metabolism
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Food ScienceInternational Journal of
Agronomy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom
Applied ampEnvironmentalSoil Science
Volume 2014
AgricultureAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
PsycheHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BiodiversityInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Plant GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biotechnology Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Forestry ResearchInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of BotanyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
EcologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Veterinary Medicine International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Cell BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
8 The Scientific World Journal
Table 4 Effects of different irrigation methods and fertilizationregimes on accumulated N2O and CH4 emissions during cottongrowing season Values are means plusmn standard deviation of threereplicates Different small letters in the same column refer tosignificant difference between treatments at 119875 lt 005 level
N2O (kg haminus1) CH4 (kg haminus1)
FC 171 plusmn 013a minus292 plusmn 096abDC 109 plusmn 011b minus887 plusmn 185bFB 121 plusmn 007b 539 plusmn 491aDB 104 plusmn 006b minus684 plusmn 107b
coordinate the mineral N availability and plant uptake Thiswould reduce the amount of N available for denitrificationand lost as N
2O [18] On the other hand decreases in
emissions of N2O in soil amended with biochar might be
attributed to improved aeration and porosity for its developedmicrostructure which might lead to lower denitrificationrates and alter the N
2O-to-N
2ratio during denitrification
[16]The present study indicated that the arid cotton fields
under FC DC and DB were the sinks of CH4 while FB was
the source of CH4 This was consistent with the results of
previous studies with different irrigation methods conductedin upland field [39ndash41] However drip irrigation was asource of CH
4in the study in cotton field [22] which was
inconsistent with the present results This might be relatedto the different rate of irrigation and fertilization Uplandfields are normally net sinks for CH
4 since the consumption
exceeds the production in CH4[42] The dry soil in upland
field limited the CH4emission however it did have a
possibility to become a source after rainfall within severaldays orweeks [43 44] Comparing theCH
4emission between
DC and FC it was shown that DC increased the uptakeof CH
4for the relative lower soil moisture in most of the
time during cotton growing season (Figure 2(a)) The mainfactor affectingCH
4uptake in summerwas soilmoisture [45]
which plays a critical role inCH4consumption [46] Decrease
in soil moisture enhanced CH4oxidation through improving
CH4diffusion from atmosphere into soil pore spaces [47] and
through gas diffusivity to control microbial oxidation whichchanges inversely with soil moisture [48 49]
In our study the addition of biochar increased CH4
emissions by 2846 higher with FB than that with FC whilethe uptake of CH
4with DB was 229 lower than that with
DC The result was in good agreement with previous studythat biochar addition promoted CH
4emissions of the upland
soil [17] However other studies had reported that biocharamendment reduces CH
4emissions as compared with the
control [18 19] The inconsistence might be attributed to thesoil type agricultural management and biochar type On onehand the addition of biochar increased the substrate sup-ply and created a favorable environment for methanogenicactivity On the other hand the CH
4emission from acid
soil was usually much lower than that from neutral soil[50] Biochar addition could increase soil PH which was abenefit for methanogenic bacteria Furthermore increasedsoil aeration due to increased porosity could increase CH
4
diffusion Biochar might play a more important role underpaddy fields compared with straw returning directly whichwould increase CH
4emission obviously [51]
There was significant difference between drip irrigationtreatments and furrow irrigation treatments in the total GWPof N2O and CH
4emissions (119875 lt 001) while fertilization
regimes showed little effect (Figure 6) The average yield-scaledGWPwas 801 and 722 lowerwithDCandDB thanthat with FC indicating that drip irrigation couldmitigate theyield-scaled GHG emissions from cotton field In previousstudies cotton yield was higher with drip irrigation thanthat with furrow irrigation [52] which agreed with ourstudy Although the difference of cotton yield between fourtreatments was insignificant WUE was significantly higherwith DC and DB than that with FC by 538 and 602respectively (119875 lt 005) (Table 3) WUE represented inthis study (from 0263 kgmminus3 to 0527 kgmminus3) were lowerthan that from the studies in Turkey where it rangedfrom 0508 kgmminus3 to 0648 kgmminus3 or from 076 kgmminus3 to146 kgmminus3 [52 53]The variance inWUE in different ecositescould be related to climate plant number varietal differencesand irrigation amount [54] It indicated that drip irrigationsignificantly increased WUE of cotton plants in relation tofurrow irrigation The relative higher WUE with DC and DBwas related to improved fertilizer efficiency and depressedleaching potential in drip irrigation system [55]
5 Conclusions
Irrigation methods significantly affected the GHG emissionsfrom cotton field in arid northwestern China Biochar addi-tion increased CH
4emissions and decreased N
2O emissions
The water supply and N fertilizer dressing method played akey role in regulating gas emissions Drip irrigation treat-ments (DC and DB) remarkably reduced GHG emissionscompared with furrow irrigation treatments (FC and FB) Inaddition drip irrigation treatments (DC and DB) had higheryield and WUE compared to furrow irrigation treatments(FC and FB) Thus mulched-drip irrigation with conven-tional fertilization or conventional fertilization + biocharshould be a better approach to increase cotton yield withdepressed GHG emissions in arid northwestern China
Abbreviations
GHG Greenhouse gasGWP Global warming potentialWUE Water use efficiency
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgment
This work was financially supported by the opened subjectof Xinjiang Key Laboratory of Water Cycle and Utilization inArid Zone (Grant no XJYS0907-2010-03)
The Scientific World Journal 9
References
[1] IPCC Climate Change 2007 The Physical Science Basis Cam-bridge University Press Cambridge UK 2007
[2] A F Bouwman L J M Boumans and N H Baffes GlobalEstimates of Gaseous Emissions of NH
3 NO and N
2O from
Agricultural Land Food and Agriculture Organisation RomeItaly 2001
[3] FAOSTAT 2002 httpfaostatfaoorg[4] C Liu X Zheng Z Zhou et al ldquoNitrous oxide and nitric oxide
emissions from an irrigated cotton field in Northern ChinardquoPlant and Soil vol 332 no 1-2 pp 123ndash134 2010
[5] TMahmood RAli J Iqbal andURobab ldquoNitrous oxide emis-sion from an irrigated cotton field under semiarid subtropicalconditionsrdquo Biology and Fertility of Soils vol 44 no 5 pp 773ndash781 2008
[6] C Scheer R Wassmann K Kienzler N Ibragimov andR Eschanov ldquoNitrous oxide emissions from fertilized irri-gated cotton (Gossypium hirsutum L) in the Aral Sea BasinUzbekistan influence of nitrogen applications and irrigationpracticesrdquo Soil Biology and Biochemistry vol 40 no 2 pp 290ndash301 2008
[7] J Li J Zhang and L Ren ldquoWater and nitrogen distributionas affected by fertigation of ammonium nitrate from a pointsourcerdquo Irrigation Science vol 22 no 1 pp 19ndash30 2003
[8] C M Kallenbach D E Rolston and W R Horwath ldquoCovercropping affects soil N
2O and CO
2emissions differently
depending on type of irrigationrdquo Agriculture Ecosystems andEnvironment vol 137 no 3-4 pp 251ndash260 2010
[9] L Sanchez-Martın A Arce A Benito L Garcia-Torres andA Vallejo ldquoInfluence of drip and furrow irrigation systems onnitrogen oxide emissions from a horticultural croprdquo Soil Biologyand Biochemistry vol 40 no 7 pp 1698ndash1706 2008
[10] L Sanchez-Martın A Meijide L Garcia-Torres and A VallejoldquoCombination of drip irrigation and organic fertilizer formitigating emissions of nitrogen oxides in semiarid climaterdquoAgriculture Ecosystems and Environment vol 137 no 1-2 pp99ndash107 2010
[11] J Lehmann ldquoBio-energy in the blackrdquo Frontiers in Ecology andthe Environment vol 5 no 7 pp 381ndash387 2007
[12] M Fowles ldquoBlack carbon sequestration as an alternative tobioenergyrdquo Biomass and Bioenergy vol 31 no 6 pp 426ndash4322007
[13] M Rondon J A Ramirez and J Lehmann ldquoCharcoal additionsreduce net emissions of greenhouse gases to the atmosphererdquo inProceedings of the 3rd USDA Symposium on Greenhouse Gasesand Carbon Sequestration p 208 Baltimore Md USA March2005
[14] A Aguilar-Chavez M Dıaz-Rojas M del Rosario Cardenas-Aquino L Dendooven and M Luna-Guido ldquoGreenhouse gasemissions from a wastewater sludge-amended soil cultivatedwith wheat (Triticum spp L) as affected by different applicationrates of charcoalrdquo Soil Biology and Biochemistry vol 52 pp 90ndash95 2012
[15] S Castaldi M Riondino S Baronti et al ldquoImpact of biocharapplication to a Mediterranean wheat crop on soil microbialactivity and greenhouse gas fluxesrdquo Chemosphere vol 85 no9 pp 1464ndash1471 2011
[16] B P Singh B J Hatton B Singh A L Cowie and A KathurialdquoInfluence of biochars on nitrous oxide emission and nitrogenleaching from two contrasting soilsrdquo Journal of EnvironmentalQuality vol 39 no 4 pp 1224ndash1235 2010
[17] J Wang X Pan Y Liu X Zhang and Z Xiong ldquoEffects ofbiochar amendment in two soils on greenhouse gas emissionsand crop productionrdquo Plant and Soil vol 360 no 1-2 pp 287ndash298 2012
[18] K Karhu T Mattila I Bergstrom and K Regina ldquoBiocharaddition to agricultural soil increased CH
4uptake and water
holding capacitymdashresults from a short-term pilot field studyrdquoAgriculture Ecosystems and Environment vol 140 no 1-2 pp309ndash313 2011
[19] C Scheer P R Grace D W Rowlings S Kimber and L vanZwieten ldquoEffect of biochar amendment on the soil-atmosphereexchange of greenhouse gases from an intensive subtropicalpasture in northernNew SouthWales AustraliardquoPlant and Soilvol 345 no 1 pp 47ndash58 2011
[20] Z Li R Zhang X Wang J Wang C Zhang and C TianldquoCarbon dioxide fluxes and concentrations in a cotton fieldin northwestern China effects of plastic mulching and dripirrigationrdquo Pedosphere vol 21 no 2 pp 178ndash185 2011
[21] Q Zhang L Yang J Wang H Luo Y Zhang and WZhang ldquoEffects of different irrigation methods and fertilizationmeasures on soil respiration and its component contribution incotton field in arid regionrdquo Scientia Agricultura Sinica vol 25no 12 pp 2420ndash2430 2012 (Chinese)
[22] Z Li R Zhang X Wang F Chen D Lai and C Tian ldquoEffectsof plastic film mulching with drip irrigation on N
2O and CH
4
emissions fromcotton fields in arid landrdquo Journal of AgriculturalScience 2013
[23] FAOIAEA Measurement of Methane and Nitrous Oxide Emis-sion from Agriculture A Joint Undertakong by the Food andAgriculture Organization of United Nations and InternationalAtomic Energy Agency International Atomic Energy AgencyVienna Austria 1992
[24] Y Huang J Jiang L Zong Q Zhou R L Sass and F MFisher ldquoInfluence of planting density and precipitation on N
2O
emission from a winter wheat fieldrdquo Environmental Science vol22 no 6 pp 20ndash23 2001 (Chinese)
[25] G C Topp J L Davis and A P Annan ldquoElectromagneticdetermination of soil water content measurements in coaxialtransmission linesrdquoWater Resources Research vol 16 no 3 pp574ndash582 1980
[26] R Lu Soil Agricultural Chemistry Analytical Method ChinaAgricultural Science and Technology Press Beijing China2000
[27] L Zhou F Li S Jin and Y Song ldquoHow two ridges andthe furrow mulched with plastic film affect soil water soiltemperature and yield of maize on the semiarid Loess Plateauof Chinardquo Field Crops Research vol 113 no 1 pp 41ndash47 2009
[28] J Clemens M P Schillinger H Goldbach and B HuweldquoSpatial variability of N
2O emissions and soil parameters of an
arable silt loammdasha field studyrdquo Biology and Fertility of Soils vol28 no 4 pp 403ndash406 1999
[29] K InubushiM A Barahona andK Yamakawa ldquoEffects of saltsand moisture content on N
2O emission and nitrogen dynamics
in Yellow soil and Andosol in model experimentsrdquo Biology andFertility of Soils vol 29 no 4 pp 401ndash407 1999
[30] B J Joslashrgensen and R N Joslashrgensen ldquoField-scale and laboratorystudy of factors affecting N
2O emissions from a rye stubble field
on sandy loam soilrdquo Biology and Fertility of Soils vol 25 no 4pp 366ndash371 1997
[31] A R Mosier and Z Zhu ldquoChanges in patterns of fertilizernitrogen use in Asia and its consequences for N
2O emissions
10 The Scientific World Journal
from agricultural systemsrdquo Nutrient Cycling in Agroecosystemsvol 57 no 1 pp 107ndash117 2000
[32] R Ruser H Flessa R Schilling F Beese and J C MunchldquoEffect of crop-specific field management and N fertilizationon N2O emissions from a fine-loamy soilrdquo Nutrient Cycling in
Agroecosystems vol 59 no 2 pp 177ndash191 2001[33] C Song and J Zhang ldquoEffects of soil moisture temperature
and nitrogen fertilization on soil respiration and nitrous oxideemission duringmaize growth period in northeast ChinardquoActaAgriculturae Scandinavica B Soil and Plant Science vol 59 no2 pp 97ndash106 2009
[34] D M Linn and J W Doran ldquoEffect of water-filled pore spaceon carbon dioxide and nitrous oxide production in tilled andnontilled soilsrdquo Soil Science Society of America Journal vol 48no 6 pp 1267ndash1272 1984
[35] X J Liu A R Mosier A D Halvorson C A Reule andF S Zhang ldquoDinitrogen and N
2O emissions in arable soils
effect of tillage N source and soil moisturerdquo Soil Biology andBiochemistry vol 39 no 9 pp 2362ndash2370 2007
[36] L Sanchez-Martın A Vallejo J Dick and U M Skiba ldquoTheinfluence of soluble carbon and fertilizer nitrogen on nitricoxide and nitrous oxide emissions from two contrasting agri-cultural soilsrdquo Soil Biology and Biochemistry vol 40 no 1 pp142ndash151 2008
[37] Z Mu S D Kimura Y Toma and R Hatano ldquoNitrous oxidefluxes from upland soils in central Hokkaido Japanrdquo Journal ofEnvironmental Sciences vol 20 no 11 pp 1312ndash1322 2008
[38] B Liang J Lehmann D Solomon et al ldquoBlack carbon increasescation exchange capacity in soilsrdquo Soil Science Society of AmericaJournal vol 70 no 5 pp 1719ndash1730 2006
[39] P Boeckx and O Van Cleemput ldquoEstimates of N2O and CH
4
fluxes from agricultural lands in various regions in EuroperdquoNutrient Cycling in Agroecosystems vol 60 no 1ndash3 pp 35ndash472001
[40] J A MacDonald U Skiba L J Sheppard et al ldquoThe effectof nitrogen deposition and seasonal variability on methaneoxidation and nitrous oxide emission rates in an upland spruceplantation andmoorlandrdquoAtmospheric Environment vol 31 no22 pp 3693ndash3706 1997
[41] S C Whalen ldquoInfluence of N and non-N salts on atmosphericmethane oxidation by upland boreal forest and tundra soilsrdquoBiology and Fertility of Soils vol 31 no 3-4 pp 279ndash287 2000
[42] J P Megonigal and A B Guenther ldquoMethane emissions fromupland forest soils and vegetationrdquo Tree Physiology vol 28 no4 pp 491ndash498 2008
[43] E A Davidson F Y Ishida and D C Nepstad ldquoEffects ofan experimental drought on soil emissions of carbon dioxidemethane nitrous oxide and nitric oxide in a moist tropicalforestrdquo Global Change Biology vol 10 no 5 pp 718ndash730 2004
[44] F LWang and J R Bettany ldquoMethane emission fromCanadianprairie and forest soils under short term flooding conditionsrdquoNutrient Cycling in Agroecosystems vol 49 no 1ndash3 pp 197ndash2021997
[45] R BrummeandWBorken ldquoSite variation inmethane oxidationas affected by atmospheric deposition and type of temperateforest ecosystemrdquo Global Biogeochemical Cycles vol 13 no 2pp 493ndash501 1999
[46] A P S Adamsen and G M King ldquoMethane consumption intemperate and subarctic forest soils rates vertical zonation andresponses to water and nitrogenrdquo Applied and EnvironmentalMicrobiology vol 59 no 2 pp 485ndash490 1993
[47] M S Castro P A Steudler J M Melillo J D Aber and R DBowden ldquoFactors controlling atmospheric methane consump-tion by temperate forest soilsrdquoGlobal Biogeochemical Cycles vol9 no 1 pp 1ndash10 1995
[48] B C Ball K A Smith L Klemedtsson et al ldquoThe influence ofsoil gas transport properties onmethane oxidation in a selectionof northern European soilsrdquo Journal of Geophysical Research Dvol 102 no 19 pp 23309ndash23317 1997
[49] K A Smith T Ball F Conen K E Dobbie J Masshederand A Rey ldquoExchange of greenhouse gases between soil andatmosphere interactions of soil physical factors and biologicalprocessesrdquo European Journal of Soil Science vol 54 no 4 pp779ndash791 2003
[50] H Feng G Cheng and L An ldquoMicrobial-mediated methanecycle in soils and global change a reviewrdquo Journal of Glaciologyand Geocryology vol 26 no 4 pp 411ndash419 2006 (Chinese)
[51] Y YanDWang and J Zheng ldquoAdvances in effects of biochar onthe soil N
2O and CH
4emissionsrdquo Chinese Agricultural Science
Bulletin vol 29 no 8 pp 140ndash146 2013 (Chinese)[52] OCetin andL Bilgel ldquoEffects of different irrigationmethods on
shedding and yield of cottonrdquo Agricultural Water Managementvol 54 no 1 pp 1ndash15 2002
[53] NDagdelenaH Basalb E Yılmaza T Gurbuza and S AkcayaldquoDifferent drip irrigation regimes affect cotton yield water useefficiency and fiber quality in western Turkeyrdquo AgriculturalWater Management vol 96 no 1 pp 110ndash120 2009
[54] N Ibragimov S R Evett Y Esanbekov B S Kamilov LMirzaev and J P A Lamers ldquoWater use efficiency of irrigatedcotton in Uzbekistan under drip and furrow irrigationrdquo Agri-cultural Water Management vol 90 no 1-2 pp 112ndash120 2007
[55] C R Camp P J Bauer and P G Hunt ldquoSubsurface dripirrigation lateral spacing and management for cotton in thesoutheastern Coastal plainrdquo Transactions of the American Soci-ety of Agricultural Engineers vol 40 no 4 pp 993ndash999 1997
Submit your manuscripts athttpwwwhindawicom
Nutrition and Metabolism
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Food ScienceInternational Journal of
Agronomy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom
Applied ampEnvironmentalSoil Science
Volume 2014
AgricultureAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
PsycheHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BiodiversityInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Plant GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biotechnology Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Forestry ResearchInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of BotanyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
EcologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Veterinary Medicine International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Cell BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World Journal 9
References
[1] IPCC Climate Change 2007 The Physical Science Basis Cam-bridge University Press Cambridge UK 2007
[2] A F Bouwman L J M Boumans and N H Baffes GlobalEstimates of Gaseous Emissions of NH
3 NO and N
2O from
Agricultural Land Food and Agriculture Organisation RomeItaly 2001
[3] FAOSTAT 2002 httpfaostatfaoorg[4] C Liu X Zheng Z Zhou et al ldquoNitrous oxide and nitric oxide
emissions from an irrigated cotton field in Northern ChinardquoPlant and Soil vol 332 no 1-2 pp 123ndash134 2010
[5] TMahmood RAli J Iqbal andURobab ldquoNitrous oxide emis-sion from an irrigated cotton field under semiarid subtropicalconditionsrdquo Biology and Fertility of Soils vol 44 no 5 pp 773ndash781 2008
[6] C Scheer R Wassmann K Kienzler N Ibragimov andR Eschanov ldquoNitrous oxide emissions from fertilized irri-gated cotton (Gossypium hirsutum L) in the Aral Sea BasinUzbekistan influence of nitrogen applications and irrigationpracticesrdquo Soil Biology and Biochemistry vol 40 no 2 pp 290ndash301 2008
[7] J Li J Zhang and L Ren ldquoWater and nitrogen distributionas affected by fertigation of ammonium nitrate from a pointsourcerdquo Irrigation Science vol 22 no 1 pp 19ndash30 2003
[8] C M Kallenbach D E Rolston and W R Horwath ldquoCovercropping affects soil N
2O and CO
2emissions differently
depending on type of irrigationrdquo Agriculture Ecosystems andEnvironment vol 137 no 3-4 pp 251ndash260 2010
[9] L Sanchez-Martın A Arce A Benito L Garcia-Torres andA Vallejo ldquoInfluence of drip and furrow irrigation systems onnitrogen oxide emissions from a horticultural croprdquo Soil Biologyand Biochemistry vol 40 no 7 pp 1698ndash1706 2008
[10] L Sanchez-Martın A Meijide L Garcia-Torres and A VallejoldquoCombination of drip irrigation and organic fertilizer formitigating emissions of nitrogen oxides in semiarid climaterdquoAgriculture Ecosystems and Environment vol 137 no 1-2 pp99ndash107 2010
[11] J Lehmann ldquoBio-energy in the blackrdquo Frontiers in Ecology andthe Environment vol 5 no 7 pp 381ndash387 2007
[12] M Fowles ldquoBlack carbon sequestration as an alternative tobioenergyrdquo Biomass and Bioenergy vol 31 no 6 pp 426ndash4322007
[13] M Rondon J A Ramirez and J Lehmann ldquoCharcoal additionsreduce net emissions of greenhouse gases to the atmosphererdquo inProceedings of the 3rd USDA Symposium on Greenhouse Gasesand Carbon Sequestration p 208 Baltimore Md USA March2005
[14] A Aguilar-Chavez M Dıaz-Rojas M del Rosario Cardenas-Aquino L Dendooven and M Luna-Guido ldquoGreenhouse gasemissions from a wastewater sludge-amended soil cultivatedwith wheat (Triticum spp L) as affected by different applicationrates of charcoalrdquo Soil Biology and Biochemistry vol 52 pp 90ndash95 2012
[15] S Castaldi M Riondino S Baronti et al ldquoImpact of biocharapplication to a Mediterranean wheat crop on soil microbialactivity and greenhouse gas fluxesrdquo Chemosphere vol 85 no9 pp 1464ndash1471 2011
[16] B P Singh B J Hatton B Singh A L Cowie and A KathurialdquoInfluence of biochars on nitrous oxide emission and nitrogenleaching from two contrasting soilsrdquo Journal of EnvironmentalQuality vol 39 no 4 pp 1224ndash1235 2010
[17] J Wang X Pan Y Liu X Zhang and Z Xiong ldquoEffects ofbiochar amendment in two soils on greenhouse gas emissionsand crop productionrdquo Plant and Soil vol 360 no 1-2 pp 287ndash298 2012
[18] K Karhu T Mattila I Bergstrom and K Regina ldquoBiocharaddition to agricultural soil increased CH
4uptake and water
holding capacitymdashresults from a short-term pilot field studyrdquoAgriculture Ecosystems and Environment vol 140 no 1-2 pp309ndash313 2011
[19] C Scheer P R Grace D W Rowlings S Kimber and L vanZwieten ldquoEffect of biochar amendment on the soil-atmosphereexchange of greenhouse gases from an intensive subtropicalpasture in northernNew SouthWales AustraliardquoPlant and Soilvol 345 no 1 pp 47ndash58 2011
[20] Z Li R Zhang X Wang J Wang C Zhang and C TianldquoCarbon dioxide fluxes and concentrations in a cotton fieldin northwestern China effects of plastic mulching and dripirrigationrdquo Pedosphere vol 21 no 2 pp 178ndash185 2011
[21] Q Zhang L Yang J Wang H Luo Y Zhang and WZhang ldquoEffects of different irrigation methods and fertilizationmeasures on soil respiration and its component contribution incotton field in arid regionrdquo Scientia Agricultura Sinica vol 25no 12 pp 2420ndash2430 2012 (Chinese)
[22] Z Li R Zhang X Wang F Chen D Lai and C Tian ldquoEffectsof plastic film mulching with drip irrigation on N
2O and CH
4
emissions fromcotton fields in arid landrdquo Journal of AgriculturalScience 2013
[23] FAOIAEA Measurement of Methane and Nitrous Oxide Emis-sion from Agriculture A Joint Undertakong by the Food andAgriculture Organization of United Nations and InternationalAtomic Energy Agency International Atomic Energy AgencyVienna Austria 1992
[24] Y Huang J Jiang L Zong Q Zhou R L Sass and F MFisher ldquoInfluence of planting density and precipitation on N
2O
emission from a winter wheat fieldrdquo Environmental Science vol22 no 6 pp 20ndash23 2001 (Chinese)
[25] G C Topp J L Davis and A P Annan ldquoElectromagneticdetermination of soil water content measurements in coaxialtransmission linesrdquoWater Resources Research vol 16 no 3 pp574ndash582 1980
[26] R Lu Soil Agricultural Chemistry Analytical Method ChinaAgricultural Science and Technology Press Beijing China2000
[27] L Zhou F Li S Jin and Y Song ldquoHow two ridges andthe furrow mulched with plastic film affect soil water soiltemperature and yield of maize on the semiarid Loess Plateauof Chinardquo Field Crops Research vol 113 no 1 pp 41ndash47 2009
[28] J Clemens M P Schillinger H Goldbach and B HuweldquoSpatial variability of N
2O emissions and soil parameters of an
arable silt loammdasha field studyrdquo Biology and Fertility of Soils vol28 no 4 pp 403ndash406 1999
[29] K InubushiM A Barahona andK Yamakawa ldquoEffects of saltsand moisture content on N
2O emission and nitrogen dynamics
in Yellow soil and Andosol in model experimentsrdquo Biology andFertility of Soils vol 29 no 4 pp 401ndash407 1999
[30] B J Joslashrgensen and R N Joslashrgensen ldquoField-scale and laboratorystudy of factors affecting N
2O emissions from a rye stubble field
on sandy loam soilrdquo Biology and Fertility of Soils vol 25 no 4pp 366ndash371 1997
[31] A R Mosier and Z Zhu ldquoChanges in patterns of fertilizernitrogen use in Asia and its consequences for N
2O emissions
10 The Scientific World Journal
from agricultural systemsrdquo Nutrient Cycling in Agroecosystemsvol 57 no 1 pp 107ndash117 2000
[32] R Ruser H Flessa R Schilling F Beese and J C MunchldquoEffect of crop-specific field management and N fertilizationon N2O emissions from a fine-loamy soilrdquo Nutrient Cycling in
Agroecosystems vol 59 no 2 pp 177ndash191 2001[33] C Song and J Zhang ldquoEffects of soil moisture temperature
and nitrogen fertilization on soil respiration and nitrous oxideemission duringmaize growth period in northeast ChinardquoActaAgriculturae Scandinavica B Soil and Plant Science vol 59 no2 pp 97ndash106 2009
[34] D M Linn and J W Doran ldquoEffect of water-filled pore spaceon carbon dioxide and nitrous oxide production in tilled andnontilled soilsrdquo Soil Science Society of America Journal vol 48no 6 pp 1267ndash1272 1984
[35] X J Liu A R Mosier A D Halvorson C A Reule andF S Zhang ldquoDinitrogen and N
2O emissions in arable soils
effect of tillage N source and soil moisturerdquo Soil Biology andBiochemistry vol 39 no 9 pp 2362ndash2370 2007
[36] L Sanchez-Martın A Vallejo J Dick and U M Skiba ldquoTheinfluence of soluble carbon and fertilizer nitrogen on nitricoxide and nitrous oxide emissions from two contrasting agri-cultural soilsrdquo Soil Biology and Biochemistry vol 40 no 1 pp142ndash151 2008
[37] Z Mu S D Kimura Y Toma and R Hatano ldquoNitrous oxidefluxes from upland soils in central Hokkaido Japanrdquo Journal ofEnvironmental Sciences vol 20 no 11 pp 1312ndash1322 2008
[38] B Liang J Lehmann D Solomon et al ldquoBlack carbon increasescation exchange capacity in soilsrdquo Soil Science Society of AmericaJournal vol 70 no 5 pp 1719ndash1730 2006
[39] P Boeckx and O Van Cleemput ldquoEstimates of N2O and CH
4
fluxes from agricultural lands in various regions in EuroperdquoNutrient Cycling in Agroecosystems vol 60 no 1ndash3 pp 35ndash472001
[40] J A MacDonald U Skiba L J Sheppard et al ldquoThe effectof nitrogen deposition and seasonal variability on methaneoxidation and nitrous oxide emission rates in an upland spruceplantation andmoorlandrdquoAtmospheric Environment vol 31 no22 pp 3693ndash3706 1997
[41] S C Whalen ldquoInfluence of N and non-N salts on atmosphericmethane oxidation by upland boreal forest and tundra soilsrdquoBiology and Fertility of Soils vol 31 no 3-4 pp 279ndash287 2000
[42] J P Megonigal and A B Guenther ldquoMethane emissions fromupland forest soils and vegetationrdquo Tree Physiology vol 28 no4 pp 491ndash498 2008
[43] E A Davidson F Y Ishida and D C Nepstad ldquoEffects ofan experimental drought on soil emissions of carbon dioxidemethane nitrous oxide and nitric oxide in a moist tropicalforestrdquo Global Change Biology vol 10 no 5 pp 718ndash730 2004
[44] F LWang and J R Bettany ldquoMethane emission fromCanadianprairie and forest soils under short term flooding conditionsrdquoNutrient Cycling in Agroecosystems vol 49 no 1ndash3 pp 197ndash2021997
[45] R BrummeandWBorken ldquoSite variation inmethane oxidationas affected by atmospheric deposition and type of temperateforest ecosystemrdquo Global Biogeochemical Cycles vol 13 no 2pp 493ndash501 1999
[46] A P S Adamsen and G M King ldquoMethane consumption intemperate and subarctic forest soils rates vertical zonation andresponses to water and nitrogenrdquo Applied and EnvironmentalMicrobiology vol 59 no 2 pp 485ndash490 1993
[47] M S Castro P A Steudler J M Melillo J D Aber and R DBowden ldquoFactors controlling atmospheric methane consump-tion by temperate forest soilsrdquoGlobal Biogeochemical Cycles vol9 no 1 pp 1ndash10 1995
[48] B C Ball K A Smith L Klemedtsson et al ldquoThe influence ofsoil gas transport properties onmethane oxidation in a selectionof northern European soilsrdquo Journal of Geophysical Research Dvol 102 no 19 pp 23309ndash23317 1997
[49] K A Smith T Ball F Conen K E Dobbie J Masshederand A Rey ldquoExchange of greenhouse gases between soil andatmosphere interactions of soil physical factors and biologicalprocessesrdquo European Journal of Soil Science vol 54 no 4 pp779ndash791 2003
[50] H Feng G Cheng and L An ldquoMicrobial-mediated methanecycle in soils and global change a reviewrdquo Journal of Glaciologyand Geocryology vol 26 no 4 pp 411ndash419 2006 (Chinese)
[51] Y YanDWang and J Zheng ldquoAdvances in effects of biochar onthe soil N
2O and CH
4emissionsrdquo Chinese Agricultural Science
Bulletin vol 29 no 8 pp 140ndash146 2013 (Chinese)[52] OCetin andL Bilgel ldquoEffects of different irrigationmethods on
shedding and yield of cottonrdquo Agricultural Water Managementvol 54 no 1 pp 1ndash15 2002
[53] NDagdelenaH Basalb E Yılmaza T Gurbuza and S AkcayaldquoDifferent drip irrigation regimes affect cotton yield water useefficiency and fiber quality in western Turkeyrdquo AgriculturalWater Management vol 96 no 1 pp 110ndash120 2009
[54] N Ibragimov S R Evett Y Esanbekov B S Kamilov LMirzaev and J P A Lamers ldquoWater use efficiency of irrigatedcotton in Uzbekistan under drip and furrow irrigationrdquo Agri-cultural Water Management vol 90 no 1-2 pp 112ndash120 2007
[55] C R Camp P J Bauer and P G Hunt ldquoSubsurface dripirrigation lateral spacing and management for cotton in thesoutheastern Coastal plainrdquo Transactions of the American Soci-ety of Agricultural Engineers vol 40 no 4 pp 993ndash999 1997
Submit your manuscripts athttpwwwhindawicom
Nutrition and Metabolism
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Food ScienceInternational Journal of
Agronomy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom
Applied ampEnvironmentalSoil Science
Volume 2014
AgricultureAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
PsycheHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BiodiversityInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Plant GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biotechnology Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Forestry ResearchInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of BotanyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
EcologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Veterinary Medicine International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Cell BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
10 The Scientific World Journal
from agricultural systemsrdquo Nutrient Cycling in Agroecosystemsvol 57 no 1 pp 107ndash117 2000
[32] R Ruser H Flessa R Schilling F Beese and J C MunchldquoEffect of crop-specific field management and N fertilizationon N2O emissions from a fine-loamy soilrdquo Nutrient Cycling in
Agroecosystems vol 59 no 2 pp 177ndash191 2001[33] C Song and J Zhang ldquoEffects of soil moisture temperature
and nitrogen fertilization on soil respiration and nitrous oxideemission duringmaize growth period in northeast ChinardquoActaAgriculturae Scandinavica B Soil and Plant Science vol 59 no2 pp 97ndash106 2009
[34] D M Linn and J W Doran ldquoEffect of water-filled pore spaceon carbon dioxide and nitrous oxide production in tilled andnontilled soilsrdquo Soil Science Society of America Journal vol 48no 6 pp 1267ndash1272 1984
[35] X J Liu A R Mosier A D Halvorson C A Reule andF S Zhang ldquoDinitrogen and N
2O emissions in arable soils
effect of tillage N source and soil moisturerdquo Soil Biology andBiochemistry vol 39 no 9 pp 2362ndash2370 2007
[36] L Sanchez-Martın A Vallejo J Dick and U M Skiba ldquoTheinfluence of soluble carbon and fertilizer nitrogen on nitricoxide and nitrous oxide emissions from two contrasting agri-cultural soilsrdquo Soil Biology and Biochemistry vol 40 no 1 pp142ndash151 2008
[37] Z Mu S D Kimura Y Toma and R Hatano ldquoNitrous oxidefluxes from upland soils in central Hokkaido Japanrdquo Journal ofEnvironmental Sciences vol 20 no 11 pp 1312ndash1322 2008
[38] B Liang J Lehmann D Solomon et al ldquoBlack carbon increasescation exchange capacity in soilsrdquo Soil Science Society of AmericaJournal vol 70 no 5 pp 1719ndash1730 2006
[39] P Boeckx and O Van Cleemput ldquoEstimates of N2O and CH
4
fluxes from agricultural lands in various regions in EuroperdquoNutrient Cycling in Agroecosystems vol 60 no 1ndash3 pp 35ndash472001
[40] J A MacDonald U Skiba L J Sheppard et al ldquoThe effectof nitrogen deposition and seasonal variability on methaneoxidation and nitrous oxide emission rates in an upland spruceplantation andmoorlandrdquoAtmospheric Environment vol 31 no22 pp 3693ndash3706 1997
[41] S C Whalen ldquoInfluence of N and non-N salts on atmosphericmethane oxidation by upland boreal forest and tundra soilsrdquoBiology and Fertility of Soils vol 31 no 3-4 pp 279ndash287 2000
[42] J P Megonigal and A B Guenther ldquoMethane emissions fromupland forest soils and vegetationrdquo Tree Physiology vol 28 no4 pp 491ndash498 2008
[43] E A Davidson F Y Ishida and D C Nepstad ldquoEffects ofan experimental drought on soil emissions of carbon dioxidemethane nitrous oxide and nitric oxide in a moist tropicalforestrdquo Global Change Biology vol 10 no 5 pp 718ndash730 2004
[44] F LWang and J R Bettany ldquoMethane emission fromCanadianprairie and forest soils under short term flooding conditionsrdquoNutrient Cycling in Agroecosystems vol 49 no 1ndash3 pp 197ndash2021997
[45] R BrummeandWBorken ldquoSite variation inmethane oxidationas affected by atmospheric deposition and type of temperateforest ecosystemrdquo Global Biogeochemical Cycles vol 13 no 2pp 493ndash501 1999
[46] A P S Adamsen and G M King ldquoMethane consumption intemperate and subarctic forest soils rates vertical zonation andresponses to water and nitrogenrdquo Applied and EnvironmentalMicrobiology vol 59 no 2 pp 485ndash490 1993
[47] M S Castro P A Steudler J M Melillo J D Aber and R DBowden ldquoFactors controlling atmospheric methane consump-tion by temperate forest soilsrdquoGlobal Biogeochemical Cycles vol9 no 1 pp 1ndash10 1995
[48] B C Ball K A Smith L Klemedtsson et al ldquoThe influence ofsoil gas transport properties onmethane oxidation in a selectionof northern European soilsrdquo Journal of Geophysical Research Dvol 102 no 19 pp 23309ndash23317 1997
[49] K A Smith T Ball F Conen K E Dobbie J Masshederand A Rey ldquoExchange of greenhouse gases between soil andatmosphere interactions of soil physical factors and biologicalprocessesrdquo European Journal of Soil Science vol 54 no 4 pp779ndash791 2003
[50] H Feng G Cheng and L An ldquoMicrobial-mediated methanecycle in soils and global change a reviewrdquo Journal of Glaciologyand Geocryology vol 26 no 4 pp 411ndash419 2006 (Chinese)
[51] Y YanDWang and J Zheng ldquoAdvances in effects of biochar onthe soil N
2O and CH
4emissionsrdquo Chinese Agricultural Science
Bulletin vol 29 no 8 pp 140ndash146 2013 (Chinese)[52] OCetin andL Bilgel ldquoEffects of different irrigationmethods on
shedding and yield of cottonrdquo Agricultural Water Managementvol 54 no 1 pp 1ndash15 2002
[53] NDagdelenaH Basalb E Yılmaza T Gurbuza and S AkcayaldquoDifferent drip irrigation regimes affect cotton yield water useefficiency and fiber quality in western Turkeyrdquo AgriculturalWater Management vol 96 no 1 pp 110ndash120 2009
[54] N Ibragimov S R Evett Y Esanbekov B S Kamilov LMirzaev and J P A Lamers ldquoWater use efficiency of irrigatedcotton in Uzbekistan under drip and furrow irrigationrdquo Agri-cultural Water Management vol 90 no 1-2 pp 112ndash120 2007
[55] C R Camp P J Bauer and P G Hunt ldquoSubsurface dripirrigation lateral spacing and management for cotton in thesoutheastern Coastal plainrdquo Transactions of the American Soci-ety of Agricultural Engineers vol 40 no 4 pp 993ndash999 1997
Submit your manuscripts athttpwwwhindawicom
Nutrition and Metabolism
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Food ScienceInternational Journal of
Agronomy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom
Applied ampEnvironmentalSoil Science
Volume 2014
AgricultureAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
PsycheHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BiodiversityInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Plant GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biotechnology Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Forestry ResearchInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of BotanyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
EcologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Veterinary Medicine International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Cell BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Submit your manuscripts athttpwwwhindawicom
Nutrition and Metabolism
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Food ScienceInternational Journal of
Agronomy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom
Applied ampEnvironmentalSoil Science
Volume 2014
AgricultureAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
PsycheHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BiodiversityInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Plant GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biotechnology Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Forestry ResearchInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of BotanyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
EcologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Veterinary Medicine International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Cell BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Top Related