Split Application- North Dakota Perspective Dave Franzen, PhD Professor Soil Science Extension Soil Specialist, NDSU, Fargo
Nitrogen Fantasy Land- -Apply N fertilizer any way at any time -Yield increases -Quality increases -Profit increases
Nitrogen Reality Land- -Source matters -Timing matters -Yield can increase (or not) -Quality may improve (or not) -Profit may increase (or not)
Slow Fast NH 4 + NO 2 - NO3 - Nitrosomonas spp Nitrobacter spp Factors influencing rate of transformation- Moisture (moist, not saturated) Temperature- max ~ 80F, min 32F ph- favored by ph > 7 slowed by ph < 6
Once nitrate is in the soil, it can be taken up by plants and microbes, or it could be leached below rooting depth temporarily, semi-permanently, or permanently; or it could be further transformed under anaerobic (low oxygen) conditions through denitrification.
Most anions are not held by soil (NO 3 -, Cl -, SO 4-2 )
Corn N timeline Application Period of greatest uptake Day 1 Day 45 Day 80 Day 120 Most susceptible period for N loss
Nitrification inhibitors- N-Serve /Instinct nitrapyrin (2-chloro-6-[trichloromethyl] pyridine) DCD, dicyandiamide (~ 67% N) Ammonium thiosulfate (some activity, not much)
Spring N, Touchton et al., 1978 N-Serve 24, Illinois Fall N, Touchton et al., 1978 N-Serve 24, Illinois
Some studies showed a yield increase with N-Serve, while others showed no yield increase. Yield increases were more a result of weather between application and N uptake rather than performance of the product. Yield increases over the seven years in Minnesota were 15 bushels per acre more for fall anhydrous ammonia + N-Serve over fall anhydrous ammonia alone, and 27 bushels per acre more for spring anhydrous ammonia compared to fall anhydrous ammonia (Randall et al., 2008).
Instinct II is a new formulation of Nitrapyrin that can be mixed with ammonium fertilizers and can stay on the soil surface without incorporation. The formulation is microencapsulated nitrapyrin. That means that nitrapyrin release is slow compared to nitrapyrin for ammonia.
NP-nitrapyrin ENP- Instinct DCD Ammonium thiosulfate
DCD- a nitrification inhibitor Found in AgrotainPlus (Agrotain, Int.) SuperU (Agrotain, Int.) Guardian DF (Conklin) Guardian DL (Conklin) Others.. Needs to be added at <1% of total N content of fertilizer needing protection. Best commercial product is about 1.2%
ESN- Agrium Images from Agrium ESN website
How ESN works (Agrium website)
Illinois- 4 locations over 12 years, ESN was similar in corn yield to urea + Agrotain, and 3 bu/a higher in yield than urea alone. In 4 years of no-till, ESN was 21 bu/a better than urea surface-applied. (Ebelhar et al., 2010)
Minnesota- 3 different ESN application methodsdeep band (4 inches), broadcast incorporated fall and spring resulted in similar corn yield to urea using the same methods over a 4-year period. (Randall and Vetsch, 2009)
Kansas- At drier locations, ESN not beneficial to corn or grain sorghum. At wetter locations, some studies showed a benefit to its use. (Weber et al., 2009a and 2009b)
An ESN blend before or at planting may also delay N release later into the season. Results from Montana and South Dakota are mixed. MT results indicate little gain from ESN over urea, but they are in a dry environment. South Dakota results showed increase in grain protein with use of ESN.
Best fit for ESN- Spring wheat/durum- in soil Corn as a blend in preplant to keep plant healthy until side-dress Maybe a 4 part urea/1 part ESN blend Enough ESN to carry N into late grain fill season for higher protein.
Region/Soil Category Preplant N rate $3 corn/40 cent N Less soil test and previous crop credit West-River 149 Eastern ND Long-term no-till 179 High clay >160 bu/a 222 High clay <160 bu/a 150* Medium texture > 160 bu/a 208 Medium texture < 160 bu/a 150* Irrigated anywhere 208
Corn Yield, bushels per acre 180 Medium Textured Sites, North Dakota, NW Minnesota and Southern Manitoba with High Yields Less than 160 Bushels Per Acre 160 140 120 100 80 60 40 20 0 y = -0.0002x 2 + 0.2498x + 83.064 R² = 0.3468 0 50 100 150 200 250 300 350 400 Total Known Available N, pounds N per acre
Corn Yield, bushels per acre 180 High Clay Sites Yielding Under 160 bushels per acre, North Dakota, NW Minnesota, and Southern Manitoba, 2001-2013 160 140 120 100 80 60 40 20 0 y = -0.0005x 2 + 0.3666x + 64.644 R² = 0.2991 0 50 100 150 200 250 300 350 400 450 Total Known Available N, pounds per acre
How to determine side-dress rate? Ground-based active-sensors are best Greenseeker (Trimble) Holland Crop Circle Sensor (Holland Scientific)
Algorithms are available for corn and are based on soil texture, region, and tillage. Important to apply side-dress from V5-V8. Later can be too late for full effect.
Distance sensor to application point = block of variable rate fertilizer applied
Example field- 160 acres Use zone sampling to direct the initial N-rate to field- Usually about ½ anticipated total N requirement Apply about 200 lb N to a small reference area
Example field- 160 acres When applicator enters the field to apply side-dress application, the reference area serves as the INSEY that is the maximum yield supported by any N rate Uploaded into controller are: -Algorithm for soil category -Any over-rides of 0 rate -Efficiency factor (0.2 to 0.6) Reference area previously highly fertilized with N
Yield Reference Yield Reference INSEY INSEY
Yield Reference Yield Field Yield estimate INSEY in field Reference INSEY INSEY
Yield Reference Yield Field Yield estimate INSEY in field Reference INSEY INSEY
Yield Corn yield difference in pounds per acre. X 1.25 % N in corn grain divided by efficiency factor 0.6 = N rate Reference Yield Field Yield estimate INSEY in field Reference INSEY INSEY
Example- Reference yield predicted- 220 bushels In-field yield estimated- 160 bushels difference = 60 bushels X 56 lb grain/bushel = 3360 pounds X 0.0125 = 42 lb N 42 /0.6 efficiency factor = 70 lb N at that location.
Normalized Average Yield, pounds per acre 2500 Response of Eastern No-Till Sunflower Normalized Yield Within Each Experiment to Total Known Available N, 2012-2015 2000 1500 1000 y = -0.0072x 2 + 3.85x + 1418.6 R² = 0.2875 500 0 0 50 100 150 200 250 300 350 400 Total Known Available N, pounds per acre
Normalized Average Yield, pounds per acre 2500 Eastern Conventional Till Confection Sunflower Normalized Yield with Total Known Available N 2000 1500 1000 500 y = -0.0087x 2 + 5.1915x + 1279.7 R² = 0.4056 0 0 50 100 150 200 250 300 350 400 450 Total Known Available N, pounds per acre
Normalized Average Yield, pounds per acre 2500 Western No-Till Oil-Seed Sunflower Normalized Yields Within Each Site, Response to Total Known Available N 2000 1500 1000 y = -0.0098x 2 + 5.1885x + 1370.3 R² = 0.574 500 0 0 50 100 150 200 250 300 350 Total Known Available N, pounds per acre
Percent Sunflower Lodging 100 90 80 70 60 50 40 30 20 10 0 Percent Sunflower Lodging with N Rate, Bottineau, North Dakota, 2015 0 50 100 150 200 250 300 Total Known Available N, pounds per acre
Western Sunflower N rate, long-term no-till, oil-seed Sunflower Seed Price $ per pound 0.2 0 N cost, $ per pound 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 Total Known Available N, pounds per acre* 0.09 126 77 31 0 0 0 0 0 0 0.12 150 115 77 43 0 0 0 0 0 0.15 150 135 106 77 50 22 0 0 0 0.18 150 150 126 101 78 54 31 9 0 0.21 150 150 140 119 98 78 58 38 19 0.24 150 150 150 132 113 95 78 60 43 0.27 150 150 150 142 125 109 93 78 62 0.30 150 150 150 150 135 121 106 92 78 * Total known available N includes soil test N to 2 feet, previous crop credit and fertilizer amendment N rate.
There were several sites where 0 N plots had less than 40% oil. This is only possible with high N subsoil All of these sites were 1 st year sunflower, or sunflower grown with at least a 5 year gap between the sunflower crop and another deep-rooted crop.
Considerations for 1 st year sunflower or many years in between sunflower crops-
Pioneer- 8 state similar protocol 2 sites per state Objective- determine best side-dress predictive tools for the NC region- results into Encirca Program Missouri Illinois Iowa Indiana Minnesota Nebraska Wisconsin North Dakota
2014- rained all through May and into June Protocol was to apply side-dress V9- too late for us. Corn suffered until side-dress- hurt yields.
Amenia, 7/10, week after side-dress. Check plot
Amenia 2014 TREATMENT YIELD Check 70.9 40 pp 108.5 80 pp 131.3 120 pp 152.9 160 pp 152.1 200 pp 168.3* 240 pp 152.6 280 pp 167.2* 40 pp 40 sd 136.2 40 pp 80 sd 147.0 40 pp 120 sd 156.1 40 pp 160 sd 150.5 40 pp 200 sd 169.4* 40 pp 240 sd 157.8 80 pp 80 sd 165.7* 80 pp 160 sd 176* LSD 5% 24.5
Durbin 2014 TREATMENT YIELD Check 34.0 40 pp 58.1 80 pp 76.7 120 pp 93.6 160 pp 106.2* 200 pp 102.6 240 pp 91.8 280 pp 103.3 40 pp 40 sd 73.9 40 pp 80 sd 76.7 40 pp 120 sd 100.1 40 pp 160 sd 106.0* 40 pp 200 sd 96.3 40 pp 240 sd 89.0 80 pp 80 sd 102.4 80 pp 160 sd 104.3* LSD 5% 29.5
2015- rained all May. Side-dress applied V5-V6. Amenia Durbin
Amenia 2015 Treatment Yield, bushels per acre Check 81 40 pp 118 80 pp 142 120 pp 160 160 pp 161 200 pp 180* 240 pp 159 280 pp 178* 40/40 153 40/80 177* 40/120 178* 40/160 175* 40/200 165 40/240 177* 80/80 161 80/160 183* LSD 31
Durbin 2015 Treatment Yield, bushels per acre Check 67 40 pp 123 80 pp 172* 120 pp 147 160 pp 165 200 pp 171* 240 pp 185* 280 pp 139 40/40 131 40/80 166 40/120 173* 40/160 158 40/200 147 40/240 140 80/80 165 80/160 159 LSD 28
Proper timing propelled Durbin yields over 180 bu/a for the first time. Need enough N to keep the corn healthy, and apply the N by V8. Study will continue in 2016.