Economics, Nitrogen Use Efficiency and Effects of Nitrogen and Sulfur Fertilizer Level
Combinations on Spring Wheat
Presenter: Dr. Jasper M Teboh, Soil Scientist, NDSU-Carrington Res. Ext. CenterCo-PI: Dr. Joel Ransom, Extension Agronomist – Cereal Crops, Dept. Plant Sciences, NDSU
Co-PI: Szilvia Yuja, Soil Research Specialist NDSU-Carrington REC
Contact: [email protected]: 701-652-2951
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RESEARCH QUESTIONS1. Does wheat respond to S application? If so,
2. How does S response relate to NUE of wheat (is there any interaction)?
3. What are the economic implications?
4. How might response differ by location or soil type?
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TREATMENTS N rates: 0, 60, 120, 180, 240 lbs N/ac S Rates: 0, 10, 20 lbs S/ac (as AMS - (NH4)2SO4
Locations, 2016: Ada - Ulen Fine Sandy Loam; SOM = 2.4% Red Lake Falls (RLF) - Wheatville Loam; SOM = 3.6% Thief River Falls (TRF) - Foxhome Sandy Loam; SOM
= 2.6%
Locations, 2015: Ada, East Grand Forks (EGF), TRF
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Site Soil Type Effect DF Yield Protein
F value P value F value P value
AdaSL;
SOM2.6%
N rate (N) 4 26.9 <0.0001 35.6 <0.0001S rate (S) 2 10.4 0.0004 3.49 0.0435
N x S 8 0.83 0.59 0.61 0.7622
EGFSiCL;SOM 3.7%
N 4 1.47 0.2726 6.05 0.0067S 2 1.44 0.2529 0.70 0.5038
N x S 8 1.49 0.2035 0.77 0.6340
TRFSL;
SOM 2.3%
N 4 0.87 0.51 50.6 <.0001S 2 0.7 0.51 3.43 0.0456
N x S 8 0.35 0.94 1.15 0.3622
Table 1. Results from 2015 wheat S x N studies
Green cells indicate significant response to fertilizer (the p values <0.05)Example, at Ada, S and N had significant effect on grain yield and protein. At EGF, N alone had significant effect on grain protein but not yield 4
Table 2. Effect of N and S on wheat grain yield and quality (Ada, 2016)
Lb/a Yield Protein Ash Fiber Starchbu/a % %
N Rate (N)0 60c 11.54b 1.46 2.786 83.1a
60 80b 11.74b 1.46 2.808 83.0a120 77b 13.04a 1.49 2.793 82.1b180 87a 13.32a 1.50 2.816 81.9bc240 83ab 13.6a 1.51 2.813 81.5c
S Rate (S)0 78 12.65 1.48 2.796 82.3
10 77 12.60 1.48 2.808 82.520 77 12.73 1.49 2.806 82.2
ANOVA ----------------------------------P-Values--------------------------------N Rate (N) <.0001 <.0001 0.0234 2.796 <.0001S Rate (S) 0.6094 0.831 0.3565 2.808 0.4417
N x S 0.5705 0.7063 0.9936 2.806 0.3331Cells highlighted in green have p<0.05, implying significant treatment effect on variable measured5
Table 3. Effect of N and S on wheat grain yield and quality (RLF, 2016)
Lbs/a Yield Protein TWT NDVI Fiber Starch Ash NDFbu/a % lb/bu % % % % %
N rate (N)0 80b 10.28c 56.4ab 0.857b 2.98a 81.62b 1.419c 8.908a60 87a 12.34b 57.20a 0.881a 2.92b 82.10a 1.464b 7.897bc
120 87a 13.30a 55.3a 0.886a 2.93ab 81.51b 1.477b 7.753c180 86ab 13.72a 54.5b 0.889a 2.96ab 80.85c 1.486ab 7.974bc240 86ab 13.99a 54.5b 0.887a 2.92b 80.73c 1.516a 8.505ab
S Rate (S)0 86 12.74 55.6 0.878 2.95 81.5 1.465 7.881b10 84 12.72 55.5 0.882 2.93 81.3 1.474 8.363ab20 85 12.72 55.6 0.881 2.94 81.3 1.479 8.378a
ANOVA -----------------------------------P-Values------------------------------------N Rate 0.028 <.0001 0.0134 <.0001 0.0105 <.0001 <.0001 0.0002S Rate 0.441 0.9974 0.9732 0.3552 0.5051 0.2025 0.2955 0.0263N x S 0.631 0.3255 0.6938 0.4488 0.3909 0.6024 0.4313 0.9516
Table 3. Effect of N and S, on wheat yield and quality (TRF, 2016)
Lb/ac Yield Protein NDVI*bu/a %
N Rate0 40.18b 15.34a 0.746b
60 49.62ab 15.58a 0.85a120 63.12a 16.00a 0.878a180 54.40a 15.26a 0.854a240 57.08a 14.06b 0.832a
Not sure why low, Effect of yield dilution, unlikely
S Rate0 48.95b 15.23 0.816b
10 54.41a 15.30 0.837a20 55.28a 15.21 0.844a
ANOVA -------------------------P-Values----------------------N Rate 0.003 <.0001 0.0001S Rate <.0001 0.5785 <.0001N x S 0.1908 0.1645 0.08
*NDVI (Normalized Difference Vegetation Index): is an index of crop vigor7
Fig 1. Yield response of spring wheat to N rates at three S levels, averaged across six site years
Averaged across: Ada (2015/2016); Sandy Loam; SOM <2.6%TRF (2015/2016); Sandy Loam; SOM (2.3/2.6%)EGF (2015): Silty Clay Loam; SOM (3.7%)RLF (2016): Loam; SOM (3.6%)
50
55
60
65
70
75
0 60 120 180 240
Yiel
d (b
u/ac
)
Nrate (lb/ac)
0lbs S10lb S20lb S
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Fig 2. Yield response of spring wheat to N rates at three S levels, averaged across two sites
and two yearsAveraged across Ada (2015/2016) with Sandy Loam, SOM <2.6% andTRF (2015/2016) with Sandy Loam, SOM (2.3/2.6%)i.e., without EGF and RLF where, SOM was >3.5% on Loam - silty clay loam
50
55
60
65
70
75
0 50 100 150 200 250 300
Yiel
d (b
u/ac
)
N Rates (Lbs N/ac)
0lbs S 10lb S 20lb S
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Fig 3. Impact of S (0, 10, 20 lbs S/a) on N rate, needed to maximize wheat yield (≈ 70 bu/ac) and protein (≈ 14.5%)
0
50
100
150
200
250
0 10 20N rate to max yield 185 180 161N rate to max protein 228 183 181
Yiel
d m
axed
at 6
9 bu
/a
Yiel
d m
axed
at 7
0 bu
/a
Yiel
d m
axed
at 6
9 bu
/a
Prot
ein
max
ed a
t 14
.47%
Prot
ein
max
ed a
t 14
.59%
Prot
ein
max
ed a
t 14
.55%
N R
ates
nee
ded
to m
axim
ize
grai
n yi
eld
and
prot
ein
(lb/a
)
S Rates (lb/a)
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Fig 4. Net revenue from applying S and N to wheat. Estimated by subtracting revenue of all treatments
from that of baseline recommended N (150 lbs/a) at 0 lbs S at Ada (2016)
Assumed fertilizer cost: N=$0.36/lb, S=$0.7/lb; Application cost = $5/ac; Grain price @ 14% protein= $4.91/bu; Premium >14 to 15% adjusted up every 0.2% at $0.06 /bu, and between 15 and16% protein, every 0.2% at $0.02/bu
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-60
-40
-20
0
20
40
0 60 120 180 240
Chan
ge in
inco
me
($/a
c)
N-Rates (lbs/a)
0 lbs S 10 lbs S 20 lbs S
Unexplainable
Baseline N rate = 150 lbs/c at 0 lb S at x-axis
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Fig 5. Net revenue from applying S and N to wheat. Estimated by subtracting revenue of all treatments from that of baseline
recommended N (130 lbs N) and 0 lbs S at RLF (2016)
Assumed fertilizer cost: N=$0.36/lb, S=$0.7/lb; Application cost = $5/ac; Grain price @ 14% protein= $4.91/bu; Premium >14 to 15% adjusted up every 0.2% at $0.06 /bu, and between 15 and16% protein, every 0.2% at $0.02/bu
-44.0
9.21.5
-6.9 -0.8
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4.5
-15.6
-43.5-43.6
-12.7 -6.7
-30.9-40.2
-80-70-60-50-40-30-20-10
01020
0 60 120 180 240
Chan
ge in
inco
me
($/a
c)
N-Rates (lbs/ac)
0lbs S 10lbs S 20lbs S Baseline N rate = 130 lbs/c at 0 lb S at x-axis
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020406080
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0 60 120 180 240
Cha
nge
in in
com
e ($
/ac)
N-Rates (lbs/ac)
0 lbs S 10 lbs S 20 lbs S Baseline N rate = 135 lbs/c at 0 lb S at x-axis
Fig 6. Net revenue from applying S and N to wheat. Estimated by subtracting revenue of all treatments from
that of baseline recommended N (135 lbs N/ac) and 0 lbs S at TRF (2016)
Assumed fertilizer cost: N=$0.36/lb, S=$0.7/lb; Application cost = $5/ac; Grain price @ 14% protein= $4.91/bu; Premium >14 to 15% adjusted up every 0.2% at $0.06 /bu, and
between 15 and16% prot., every 0.2% at $0.02/bu 13
Remarks and Outlook Wheat and protein responded significantly to N across sites; but
no interaction of N with S S increased yield by about 5.5 bushels (averaged across N rates)
at TRF at 10 lbs S compared to the control The amount of N needed to maximize yield and protein was less
with S application (Fig 3), suggesting S improved NUE Yield and protein response to S across sites clearly showed that
soils with SOM < 3% and in lighter soils (e.g. sandy loam) At 10lb S, 120lb N revenue increased by $50/ac over the control
at TRF, and by $3 at RLF We also observed that return on S application was more likely
when adequate N rates are used, i.e., close to the state N fertilizer recommendation
Results from 2016 are by no means conclusive, but relevant as we learned how much S fertility can impact revenue
Funding for this project is being sought for the final year 14
The Minnesota Wheat and Promotion CouncilProducers: Mr. Pete Kappes (Ada); Mr. Ken Asp (TRF); Mr. John Barrett (East GF)Technicians: Russ Severson, Bill Craig, Nathan JohnsonResearchers: Mr. Chad Deplazes (Research Specialist, NDSU); Dr. Grant Mehring (Research
Director – MWRPC and NDCUC, Research Assistant Professor, Dept. of Plant Sciences, NDSU); Dr. Dan Kaiser, Extension Soil Fertility Specialist, University of Minnesota
ACKNOWLEDGEMENT
Dave Torgerson Kaylina Paulley Lauren Proulx Katie Kainz15
