MEASUREMENT OF SOIL ELECTRICAL PROPERTIES FOR THE CLASSIFICATION OF MANAGEMENT VARIANTS T. TÓTH 1,...
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Transcript of MEASUREMENT OF SOIL ELECTRICAL PROPERTIES FOR THE CLASSIFICATION OF MANAGEMENT VARIANTS T. TÓTH 1,...
MEASUREMENT OF SOIL MEASUREMENT OF SOIL ELECTRICAL PROPERTIES FOR THE ELECTRICAL PROPERTIES FOR THE CLASSIFICATION OF MANAGEMENT CLASSIFICATION OF MANAGEMENT
VARIANTSVARIANTS
T. TÓTH1, A. RISTOLAINEN2,V. NAGY3,D. KOVÁCS1,CS. FARKAS1
1RISSAC, 2MTT, 3Institute of Hydrology Slovak Academy of Sciences
5th Alps-Adria Scientific Workshop 7 March 2006, Opatija, Croatia
Scheme of thScheme of thisis presentation presentation
-Objectives
-Research transects
-Instruments
-Analysis of differences between management variants
-Analysis of correlation between field values and laboratory data
-Conclusions
ObjectivesObjectives
Comparison of five field instruments, which are used as indirect techniques for the characterization of soil electrical properties, in order to distinguish classes of soil salinity, texture, vegetation and soil management.
First question: are the instruments useful or not? The answer is given by ANOVA between management variants.
Second question: what do the instruments tell us? The answer is given by correlation analysis between instrumental readings and laboratory measured values.
Data collectionData collection- Field measurements: ECa - electrical conductivity
- volumetric water content through - permittivity @ 1 m interval
- Soil sampling for analysing soil physical and chemical properties @ 5 m interval
Site descriptionSite description- Kiskunság Region, Hungarian Plain: mosaic-like soil cover- Three 70 m long transects on 10 Nov 2004
Rhoades et al.1999
Arrangement Amount/ratio
of soil constituents: water, charged particles, ions,
Conductivity EM & capacitance
EM=EM=EMRC-EMRC-120120
M_ec=M_ec=Martek SCTMartek SCT
CF_ec=Con-CF_ec=Con-ductivity forkductivity fork
P_ecP_ec&&PP__perper==Plak Plak percometerpercometer
Volw=Volw=BR-30BR-30
OperaOpera--tion tion principleprinciple
Electro-magnetic induction
Resistivity/conductivity
Resistivity/conductivity
Capa-citance
Capa-citance
OperaOpera--tion fre-tion fre-quencyquency
aprox. 10 kHz
120-1000 Hz 500 Hz 75 kHz for EC=P_ec50 MHz for wat.content= P_per
30 MHz
Specifi-Specifi-cationscations
Coil spacing 1 m
Dipole configuration,0.90m el. spacing
Wenner array,0.48 m el. spacing
Opera-Opera-tion tion depthdepth
1-1.5 m with vertical coil
~0.45 m ~0.25 m 0.20 m 0.10 m
Technical parametersTechnical parameters of instruments of instruments
OPERATION PRINCIPLE OF EM & ECa METERS
+ variants of heights
CF_ec
P_ec & P_per
P_ec & P_per
CF_ec
Instruments 1-CF_ecCF_ec (Conductivity fork, Geological Survey of Finland)-P_ecP_ec and P_per and P_per (cond/capac probe “Percometer”, Adek ltd., Est)
EM
M_ec
Volw
Instruments 2-M_ecM_ec (4 electrode resistivity sensor, Martek Instruments, US)
-EMEM (EMRC-120 instrument, Hungary)
-VolwVolw (capacitance probe “BR-30, RISSAC, Hungary)
Transect studies and differences between management variants
Non saline highest spot
Slightly saline spot
Saline lowest spot
TTransect ransect 2 – salt-affected grassland with small 2 – salt-affected grassland with small shift in texture and big change in elevationshift in texture and big change in elevation
Low lying extreme saline spot
1
10
100
1000
1 11 21 31 41 51 61 71
Log
(m
S m
-1)
M_ec20 M_ec40 Cf_ec
EM_ground EM_lifted P_ec
Extreme saline spot
ECa 0-0.45 m Cala Ach-F Art-F Puc Cam
Cases (n) 4 27 20 14 6
Calamagrostis \ - + + +
Ach-Festucetum \ + + +
Art-Festucetum \ - +
Puccinellietum \ +
Soil Moisture (0.10 m) Cala Ach-F Art-F Puc Cam
Cases (n) 4 27 20 14 6
Calamagrostis \ - - - +
Ach-Festucetum \ - - +
Art-Festucetum \ - +
Puccinellietum \ +
Wheat in the lowest & least sandy spot
Forest in highest & most sandy spot
TTransect ransect 3 – across 3 – across border border ofof forest and wheat forest and wheat field with largefield with large shift in texture shift in texture and big change in and big change in elevationelevation
Transect 3.
0
10
20
30
40
50E
C (
mS
m-1
)
Forest Headland Wheatsignificant differences between the 2 categories!!
Pasture
Maize fallow
Wheat
TTransect ransect 1 – different soil management and 1 – different soil management and crops, no changes in texture and elevationcrops, no changes in texture and elevation
Transect 1.
0
10
20
30
40
50E
C (
mS
m-1
)
Pasture Maize Headland Wheat
ECa 0-0.45 m
Pasture Wheat Maize Soil
Moisture (0.10 m)
Pasture Wheat Maize
Cases (n) 13 12 38 Cases (n) 13 12 38
Pasture / + - Pasture / - -
Wheat / + Wheat / +
Correlations
EM_
ground EM_ lifted
M_ec_ shallow
M_ec_ deep
CF_ec P_ec Volw
EM_lifted 0.95 1 M_ec_shallow 0.76 0.84 1 M_ec_deep 0.80 0.88 0.99 1 CF_ec 0.79 0.87 0.98 0.99 1 P_ec 0.89 0.95 0.92 0.94 0.94 1 Volw 0.36 0.25 -0.01 0.02 0.01 0.24 1 P_per 0.33 0.20 -0.04 -0.02 -0.09 0.13 0.81
Correlation coefficients between different instrument
readings in three transects (n=210). Values in Bold are
statistically significant (p<0.01)
1 .951 ** .755 ** .804 ** .720 ** .832 ** .782 **.951 ** 1 .840 ** .885 ** .815 ** .914 ** .872 **.755 ** .840 ** 1 .993 ** .981 ** .953 ** .979 **.804 ** .885 ** .993 ** 1 .977 ** .975 ** .987 **.720 ** .815 ** .981 ** .977 ** 1 .956 ** .990 **.832 ** .914 ** .953 ** .975 ** .956 ** 1 .988 **.782 ** .872 ** .979 ** .987 ** .990 ** .988 ** 1
EMSEMWECA20ECA40EC20EC2040EC40
EMS EMW ECA20 ECA40 EC20 EC2040 EC40
Correlation is significant at the 0.01 level (2-tailed).**.
Correlations between field measured and laboratory values
EC40
4.03.53.02.52.01.51.0.50.0
EC
A4
0600
500
400
300
200
100
0
-100
Vegetation
Headland
Forest
Maize
Wheat
Pasture
Camphorosmetum
Puccinellietum
Artemisio-Festucetum
Achilleo-Festucetum
Calamagrostis
Soil parameter M_ec
Clay (<0.002 mm) 0.73
Silt (0.002-0.05 mm) 0.30
Sand (>0.05 mm) -0.52
Humus (g g-1) -0.74
Water (g g-1) -0.21
pH 0.86
EC (mS) 0.98
Correlation between soil parameters sampled in the 3 transects at the depth of 0-0.20 m and soil electrical conductivity (n=45). Values in Bold are statistically
significant (p<0.01)
y = 0.8462x - 9.8752
R2 = 0.819
1.0
10.0
100.0
1000.0
0.0 10.0 20.0 30.0 40.0 50.0
Volumetric water ( m3 100 m3)
Lo
g(E
Ca
[m
S m-1
])
1. trans 2. trans 3. trans
MOIST40
22201816141210
EC
40
4.0
3.5
3.0
2.5
2.0
1.5
1.0
.5
0.0
Vegetation
Headland
Forest
Maize
Wheat
Pasture
Camphorosmetum
Puccinellietum
Artemisio-Festucetum
Achilleo-Festucetum
Calamagrostis
MOIST40
22201816141210
EC
40
.5
.4
.3
.2
.1
0.0
Vegetation
Headland
Forest
Maize
Wheat
Pasture
Camphorosmetum
Puccinellietum
Artemisio-Festucetum
Achilleo-Festucetum
Calamagrostis
Conclusions
•Soil salinity, textural differences and also management variants can be distinguished with decreasing statistical significance
• The methods show close correlation between instrumental readings and with the laboratory standard methods