north dakota spring wheat and durum fertilizer recommendation revisions
DESCRIPTION
Fertilizer recommendations for spring wheat and durum are being revised and revision will be published December 1, 2009. The presentation goes through the revision process and a view of the web interactive recommendation mechanism.TRANSCRIPT
Spring Wheat and Durum Fertilizer Recommendations
Revisions
Dave Franzen
Recommendations that are recent and that I am very confident about:
Canola, Flax, Barley, Sugarbeet, Dry beans
Recommendations that are out-of-date and I am not confident in them as currently written:
Wheat, corn, sunflower, most others
Several at NDSU have been working to update wheat N recommendations for five years.
I gathered all of our modern N calibration data (since 1970) along with recent and ongoing research. Here is what we have learned -
In the old days, we would add a regression line and a sill on the yield response for the state and call it good. The result of this exercise would look like this-
The “Return to N” model-
Developed by John Sawyer, Iowa State and Emerson Nafziger, Illinois (2005, Proc. Ext-Ind Soil Fert. Conf.)
This model is used in several corn-belt states, including Iowa, Illinois, Wisconsin, Minnesota, Ohio, Indiana and Michigan
Steps to implementation of Return to N-
-Generate yield response data -Use regression model from data to predict yield at N rates from 0 to maximum reasonable rate.-Generate gross return from each N rate-Generate cost of N from N rate- Subtract Cost of N from Gross return from N
Steps to implementation of Return to N in Wheat, or crops with quality factor-
-Generate yield response data -Use regression model from data to predict yield at N rates from 0 to maximum reasonable rate.-Generate quality response data-Use regression model to predict quality at N rates-Generate gross return from each N rate-Generate cost of N from N rate- Subtract Cost of N from Gross return from N
Langdon Region-Low = less than 40 bu/acreMedium = 41-60 bu/acreHigh = greater than 60 bu/acre
Eastern Region-Low= less than 40 bu/acreMedium=41-60 bu/acreHigh= greater than 60 bu/acre
Western Region-Low= less than 30 bu/acreMedium=31-50 bu/acreHigh=greater than 50 bu/acre
Effect of Tillage-
No-Till growers insist that after about 5 years, they can reduce their N rates substantially without harm.
Under No-till, the first 5 years it takes extra N (about 20 lb N extra)
After 5 years, can the rate be reduced?
N Costs cents per pound NWheat price 20 30 40 50 60 70 80 90 100
$3.00 100 80 70 60 50 45 40 0 0$4.00 105 95 85 75 65 55 45 30 30$5.00 110 100 90 80 70 60 50 40 60$6.00 115 110 105 100 95 90 85 80 60$7.00 115 110 105 100 95 90 85 80 60$8.00 115 110 105 100 95 90 85 80 60$9.00 115 110 105 100 95 90 85 80 65
$10.00 115 110 105 100 95 90 85 80 60
N rates, Western ND, Low Productivity
N Costs cents per pound N
Wheat price 20 30 40 50 60 70 80 90 100
$3.00 175 170 160 150 140 130 110 0 0$4.00 180 175 170 160 150 140 130 120 100$5.00 185 180 175 170 160 150 140 130 120$6.00 190 185 180 175 170 160 150 145 140$7.00 190 185 180 175 170 160 150 145 140$8.00 190 185 180 175 170 160 150 145 140$9.00 190 185 180 175 170 160 150 145 140
$10.00 190 185 180 175 170 160 150 145 140
N rates, Western ND, High Productivity
N Costs cents per pound NWheat price 20 30 40 50 60 70 80 90 100
$3.00 75 70 60 50 25 0 0 0 0$4.00 80 75 70 60 40 40 30 20 0$5.00 100 90 80 70 60 50 40 30 20$6.00 125 120 115 110 105 100 90 80 70$7.00 140 130 120 115 110 105 95 85 75$8.00 150 140 130 120 115 110 105 100 95$9.00 155 150 145 140 135 130 125 120 115
$10.00 160 155 150 145 140 135 130 125 120
N rates, Eastern ND, Low Productivity
N Costs cents per pound N
Wheat price 20 30 40 50 60 70 80 90 100
$3.00 200 190 175 150 125 60 0 0 0$4.00 250 235 220 200 180 160 120 100 0$5.00 250 235 220 200 190 180 160 140 120$6.00 250 250 225 210 200 190 180 160 150$7.00 250 250 250 240 220 200 190 180 175$8.00 250 250 250 250 225 210 200 190 180$9.00 250 250 250 250 250 220 210 200 190
$10.00 250 250 250 250 250 240 230 220 200
N rates, Eastern ND, High Productivity
There is ample evidence that within a region an organic matter adjustment to make between fields or within fields may be justified.
We are planning a series of experiments state-wide in 2009 that will address that question.
After those experiments are completed, the new recommendations will be formulated.
Other changes- Phosphorus-
Potassium recommendations-Soil test K > 100 ppm, no additional K
required. KCl (0-0-60-50Cl) may be applied
if Cl levels are low.
Soil test K 100 ppm or less, apply 50 lb/acre KCl (25 lb/acre K2O)