Results and Discussion
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Heavy Metal Accumulation in Wheat Forage and Grain in a Continuous Biosolid Experiment K.J. Wynn, N.T. Basta, W.E. Thomason, E.V. Lukina, G.V. Johnson, K.W. Freeman, R.L. Westerman, and W.R. Raun Department of Plant and Soil Sciences, Oklahoma State University, Stillwater, OK 74078 Results and Discussion Results and Discussion Biosolids Applied (538 kg N ha Biosolids Applied (538 kg N ha -1 -1 ) ) Year 1993 1994 1995 1996 1997 Avg. U.S. median Mo (ppm) 50.2 9.3 25.7 16.7 16.4 17.0 9.0 Cu (ppm) 928 756 684 454 507 600 741 Mo (kg ha -1 ) 0.47 0.17 0.26 0.15 0.15 0.18 --- Cu/Mo M o m g k g - - 1 Totalnitrogen and m oisture contentofStillw atersew age sludge, 1993 to 2000. ____________________________________________________ 1993 1994 1995 1996 1997 1998 1999 2000 Avg. ------------------------------------- Total N ,% --------------------------------------- 2.02 1.74 1.97 2.73 2.42 2.43 2.02 2.44 2.22 ------------------------------------- M oisture,% ------------------------------------- 60 35 59 na 55 46 45 17 45 ____________________________________________________ From 1994 to 1997,AN treatm ents atthe sam e N rate resulted in significantly greatergrain yields w hen com pared to sew age sludge. Poorstand and w eed pressure adversely affected yields in 1996 By 1998,no differences in grain yield could be detected betw een AN and SS treatm ents In 1999,SS treatm ents had significantly low eryields w hen com pared to the sam e N rates using AN Treatm entstructure and grain yield m eans,1994-2000,S tillw ater,O K . ___________________________________________________________________________________________________ Treatm entN rate N Source 1994 1995 1996 1997 1998 1999 2000 A verage 1 0 - 0.46 0.50 0.61 1.13 1.94 0.91 0.92 0.92 2 0 - 0.38 0.52 0.58 1.28 1.61 0.90 0.97 0.89 3 40 BS 0.52 0.57 0.73 1.56 2.38 0.95 1.31 1.14 4 80 BS 0.62 0.57 0.66 1.51 2.24 1.07 1.50 1.17 5 160 BS 0.89 0.57 1.24 1.40 3.05 1.36 1.57 1.44 6 240 BS 1.03 0.61 0.92 1.39 2.83 0.96 1.23 1.28 7 480 BS 1.51 1.03 0.82 1.46 3.60 1.83 1.92 1.74 8 40 AN 1.78 0.62 0.34 1.37 2.06 0.90 1.72 1.26 9 80 AN 1.74 0.91 0.51 1.76 2.86 1.61 2.88 1.75 10 160 AN 1.92 1.20 0.67 2.18 3.44 2.37 3.30 2.15 11 240 AN 2.59 1.42 0.54 2.35 3.04 2.89 2.78 2.23 12 480 AN 2.34 1.28 0.56 2.55 3.10 2.47 2.05 2.05 13 480 B S+L 1.67 1.05 0.88 1.63 3.73 2.60 1.57 1.87 14 480 A N +L 2.18 1.32 0.78 2.84 3.71 2.86 2.21 2.27 SED 0.18 0.17 0.19 0.32 0.29 0.33 0.36 CV , % 15 24 34 22 13 24 28 _________________________________________________________________________________________________ L -lim e applied ata rate of8960 kg/ha (4 tons/acre)in the fall of1993 L – lim e applied ata rate of8960 kg/ha (4 tons/acre)in the fall of1999 (87% ECCE) L -lim e applied ata rate of12,992 kg/ha (5.8 tons/acre)in the fall of2000 (85% ECCE) BS -sew age sludge obtained from the C ity ofStillw ater AN -am m onium nitrate (34-0-0) SED -standard errorofthe difference betw een tw o equally replicated m eans C V -coefficientofvariation,% N Rate kg ha -1 N Rate kg ha -1 C u m g k g - 1 Results and Discussion C u m g k g - 1 N Rate kg ha -1 •When applying 538 kg N ha -1 as biosolids, critical levels of 5 mg kg -1 Mo and 100 mg kg -1 Cu were not exceeded in wheat forage •After 7 years, 2 times the N rate was required for sewage sludge to achieve the same yield as ammonium nitrate •Biosolid application decreased forage Cu/Mo ratios compared to 34-0-0, but did not fall below critical level of 2 References O’Connor, G.A., and L.R. McDowell. 1999. Understanding fate, transport, bioavailability, and cycling of metals in land-applied biosolids. Water Environment Federation. National Research Council (NRC). 1996. Nutrient requirement of domestic animals. 7 th Ed. National Academy of Sci., National Materials and Methods Experimental Design: RCB, 3 Reps Treatments: 14 N Sources: Biosolid, Ammonium Nitrate N Rates: 0, 45, 90, 180, 270, 538 kg N ha -1 yr -1 Non-factorial treatments: Lime applied at high N rate (both sources) Planting: October 15, 1998 Forage Sampling: Clipped at ground level (1m 2 ) at Feekes growth stage 4 Winter Wheat Variety: Tonkawa Summary • High concentrations of molybdenum can cause molybdenosis in cattle • If the Cu/Mo ratio (in consumed forage) falls below 2 molybdenosis will occur. • Winter wheat forage sampled in December • Biosolids applied at 0-538 kg N/ha • Forage analyzed for Cu and Mo • Cu/Mo ratios were lower where biosolids were applied • Critical levels of 5 mg kg -1 Mo and 100 mg kg -1 Cu were not exceeded in forage • After 7 years, 2 times the N rate was required for sewage sludge to achieve the same yield as ammonium nitrate • Biosolid application decreased forage Cu/Mo ratios compared to 34-0-0, but did not fall below critical level of 2 • Unwashed wheat forage contained more Cu and Mo but Cu/Mo ratio for BS was the same for washed & unwashed forage. N Rate kg ha -1 Forage Collection Hand-clipped at Feekes 4 from 1m 2 in each plot Samples split; washed & unwashed. Forage Processing: Samples dried and ground to pass 150 uM (100 mesh) Chemical Analyses: Wet digestion (HNO 3 /HClO 4 ) ICP analysis, TJA IRIS ICP, 202.0 nm Practical quantitation limit 10 ppb Mo (0.2 ppm forage) Soil Type: Norge Loam (fine mixed, thermic Udertic Paleustoll) M o m g k g - 1 N Rate kg ha -1 SoilM olybdenum 0 0.2 0.4 0.6 0.8 1 1.2 0 45 90 180 270 538 BS AN 0 5 10 15 20 25 30 35 0 45 90 180 270 538 BS AN Soil Copper Copperin W heatForage, Feekes 4 0 2 4 6 8 10 12 14 16 0 45 90 180 270 538 BS-unw ash A N-unw ash BS-w ash A N-w ash Cu/Mo Ratio 0 20 40 60 80 100 120 140 160 0 45 90 180 270 538 AN-wash BS-wash BS-unwash AN-unwash M olybdenum in W heatForage,Feekes 4 0 0.5 1 1.5 2 0 45 90 180 270 538 BS-unw ash A N-unw ash BS-w ash A N-w ash
description
Heavy Metal Accumulation in Wheat Forage and Grain in a Continuous Biosolid Experiment K.J. Wynn, N.T. Basta, W.E. Thomason, E.V. Lukina, G.V. Johnson, K.W. Freeman, R.L. Westerman, and W.R. Raun Department of Plant and Soil Sciences, Oklahoma State University, Stillwater, OK 74078. - PowerPoint PPT Presentation
Transcript of Results and Discussion
Heavy Metal Accumulation in Wheat Forage and Grain in a Continuous Biosolid ExperimentK.J. Wynn, N.T. Basta, W.E. Thomason, E.V. Lukina, G.V. Johnson,
K.W. Freeman, R.L. Westerman, and W.R. RaunDepartment of Plant and Soil Sciences, Oklahoma State University, Stillwater, OK 74078
Results and Discussion Results and Discussion
Biosolids Applied (538 kg N haBiosolids Applied (538 kg N ha-1-1))Year19931994199519961997Avg.U.S.
median
Mo (ppm) 50.29.3
25.716.716.417.0
9.0
Cu (ppm)928756684454507600
741
Mo (kg ha-1)0.470.170.260.150.150.18
---
Cu/
Mo
Mo
mg
kg--
1
Total nitrogen and moisture content of Stillwater sewage sludge, 1993 to 2000. ____________________________________________________ 1993 1994 1995 1996 1997 1998 1999 2000 Avg. -------------------------------------Total N, % --------------------------------------- 2.02 1.74 1.97 2.73 2.42 2.43 2.02 2.44 2.22 ------------------------------------- Moisture, % ------------------------------------- 60 35 59 na 55 46 45 17 45 ____________________________________________________ From 1994 to 1997, AN treatments at the same N rate resulted in
significantly greater grain yields when compared to sewage sludge.
Poor stand and weed pressure adversely affected yields in 1996 By 1998, no differences in grain yield could be detected between
AN and SS treatments In 1999, SS treatments had significantly lower yields when
compared to the same N rates using AN
Treatment structure and grain yield means, 1994-2000, Stillwater, OK.___________________________________________________________________________________________________
TreatmentN rate N Source 1994 1995 1996 1997 1998 1999 2000 Average kg ha-1 --------------------------------------Mg ha -1 ----------------------------- 1 0 - 0.46 0.50 0.61 1.13 1.94 0.91 0.92 0.922 0 - 0.38 0.52 0.58 1.28 1.61 0.90 0.97 0.893 40 BS 0.52 0.57 0.73 1.56 2.38 0.95 1.31 1.144 80 BS 0.62 0.57 0.66 1.51 2.24 1.07 1.50 1.175 160 BS 0.89 0.57 1.24 1.40 3.05 1.36 1.57 1.446 240 BS 1.03 0.61 0.92 1.39 2.83 0.96 1.23 1.287 480 BS 1.51 1.03 0.82 1.46 3.60 1.83 1.92 1.748 40 AN 1.78 0.62 0.34 1.37 2.06 0.90 1.72 1.269 80 AN 1.74 0.91 0.51 1.76 2.86 1.61 2.88 1.7510 160 AN 1.92 1.20 0.67 2.18 3.44 2.37 3.30 2.1511 240 AN 2.59 1.42 0.54 2.35 3.04 2.89 2.78 2.2312 480 AN 2.34 1.28 0.56 2.55 3.10 2.47 2.05 2.0513 480 BS+L 1.67 1.05 0.88 1.63 3.73 2.60 1.57 1.8714 480 AN+L 2.18 1.32 0.78 2.84 3.71 2.86 2.21 2.27
SED 0.18 0.17 0.19 0.32 0.29 0.33 0.36CV, % 15 24 34 22 13 24 28_________________________________________________________________________________________________
L - lime applied at a rate of 8960 kg/ha (4 tons/acre) in the fall of 1993L – lime applied at a rate of 8960 kg/ha (4 tons/acre) in the fall of 1999 (87% ECCE)L - lime applied at a rate of 12,992 kg/ha (5.8 tons/acre) in the fall of 2000 (85% ECCE)BS - sewage sludge obtained from the City of StillwaterAN - ammonium nitrate (34-0-0)SED - standard error of the difference between two equally replicated meansCV - coefficient of variation, %
N Rate kg ha -1
N Rate kg ha -1
Cu
mg
kg
-1
Results and Discussion
Cu
mg
kg
-1
N Rate kg ha -1
•When applying 538 kg N ha-1 as biosolids, critical levels of 5 mg kg-1 Mo and 100 mg kg-1 Cu were not exceeded in wheat forage
•After 7 years, 2 times the N rate was required for sewage sludge to achieve the same yield as ammonium nitrate
•Biosolid application decreased forage Cu/Mo ratios compared to 34-0-0, but did not fall below critical level of 2
References
O’Connor, G.A., and L.R. McDowell. 1999. Understanding fate, transport, bioavailability, and cycling of metals in land-applied biosolids. Water Environment Federation.
National Research Council (NRC). 1996. Nutrient requirement of domestic animals. 7 th Ed. National Academy of Sci., National Research Council, Wash. D.C.
Materials and MethodsExperimental Design:
RCB, 3 Reps
Treatments:
14
N Sources:
Biosolid, Ammonium Nitrate
N Rates:
0, 45, 90, 180, 270, 538 kg N ha-1 yr-1
Non-factorial treatments:
Lime applied at high N rate (both sources)
Planting:
October 15, 1998
Forage Sampling:
Clipped at ground level (1m2) at Feekes growth stage 4
Winter Wheat Variety:
Tonkawa
Summary• High concentrations of molybdenum can cause
molybdenosis in cattle
• If the Cu/Mo ratio (in consumed forage) falls below 2 molybdenosis will occur.
• Winter wheat forage sampled in December
• Biosolids applied at 0-538 kg N/ha
• Forage analyzed for Cu and Mo
• Cu/Mo ratios were lower where biosolids were applied
• Critical levels of 5 mg kg-1 Mo and 100 mg kg-1 Cu were not exceeded in forage
• After 7 years, 2 times the N rate was required for sewage sludge to achieve the same yield as ammonium nitrate
• Biosolid application decreased forage Cu/Mo ratios compared to 34-0-0, but did not fall below critical level of 2
• Unwashed wheat forage contained more Cu and Mo but Cu/Mo ratio for BS was the same for washed & unwashed forage.
N Rate kg ha -1
Forage Collection
Hand-clipped at Feekes 4 from 1m2 in each plot
Samples split; washed & unwashed.
Forage Processing:
Samples dried and ground to pass 150 uM (100 mesh)
Chemical Analyses: Wet digestion (HNO3/HClO4)
ICP analysis, TJA IRIS ICP, 202.0 nm
Practical quantitation limit 10 ppb Mo (0.2 ppm forage)
Soil Type:
Norge Loam (fine mixed, thermic Udertic Paleustoll)
Mo
mg
kg-1
N Rate kg ha -1
Soil Molybdenum
0
0.2
0.4
0.6
0.8
1
1.2
0 45 90 180 270 538
BS
AN
0
5
10
15
20
25
30
35
0 45 90 180 270 538
BS
AN
Soil Copper
Copper in Wheat Forage, Feekes 4
0
2
4
6
8
10
12
14
16
0 45 90 180 270 538
BS-unwashAN-unwashBS-washAN-wash
Cu/Mo Ratio
020
4060
80100
120140
160
0 45 90 180 270 538
AN-washBS-washBS-unwashAN-unwash
Molybdenum in Wheat Forage, Feekes 4
0
0.5
1
1.5
2
0 45 90 180 270 538
BS-unw ash
AN-unw ash
BS-w ash
AN-w ash
