Fertilizer Rates when Costs are High (Part 3- specifics for crops) (04/28/22)
Corn- Use N calculator, Starter P important, Use K calculator for K rates https://www.ndsu.edu/pubweb/soils/corn_k/ or download North Dakota K calculator for iPhones and Androids, use sulfate-based S at a rate at least 10 pounds S per acre, use Zn in the starter if soil test DTPA Zn is less than 1 ppm.
Soybean- No N recommended, high residual nitrate-N is not a deterrent, although in IDC-prone areas, a companion cover crop of barley, oats should be seeded when soybean is seeded to reduce IDC severity from higher soil nitrate. Except in the sandiest soils, S should not be required, but if it keeps raining, be alert. P is recommended when soil P test is 7 ppm or less. Broadcast P, not starter. Potassium if soil test is low- see circular for critical value.
Canola- N rate is capped, and the N rate should not be decreased even as high as N costs are today. P should go into the starter, and a starter should always be used. Consult the rate limitations in the canola fertilizer circular. Potassium should not be a problem in most of our soils. Consult your soil tests and the circular. ALWAYS apply sulfate-S. Elemental S is not helpful, even if applied in the fall. No micronutrients are necessary.
Small grains- for spring wheat/durum, use N calculator for rate. Apply at least 10 pounds per acre sulfate-S fertilizer (usually ammonium sulfate). Use a P-based starter. Potassium is generally not necessary. Responses of wheat to chloride (Cl) are small, and due to K prices, probably not cost effective this season. No micronutrients are necessary.
Barley- 2-row malting- new research from NDSU indicates that rate should be 140 pounds total known N for greatest yield, and due to higher prices 120 pounds total known N is probably more profitable. From 120, subtract soil nitrate-N to 2 feet in depth and subtract any previous crop credits. The result will be a profitable 2-row malting barley rate that should result in near maximum yield, with acceptable protein and plump. Always use a P-based starter. Apply potash if chloride is less than 40, but 5 pounds Cl per acre is enough in a band to generate the plump required at harvest. Apply sulfate-S at 10 pounds S per acre. Elemental S is not helpful. No micronutrients are required.
Oats- follow circular for N rate https://www.ndsu.edu/fileadmin/soils.del/pdfs/North_Dakota_Fertilizer_Recommendation_Tables_and_Equations_SF882.pdf starter P is important. Potassium only if soil test is less than 100 ppm. Apply sulfate-S at 10 pounds S/acre. No micronutrients required.
Sugar beet- use circular rate provided in North Dakota publication or Minnesota publication, depending on where your farm is. Do not reduce the rate of N due to higher N prices. Your sugar check will suffer for it.
Sunflower- Use N calculator for rate. Sulfur is not required except in the soils with deep sands, deep water table and lots of fall to spring rains/snow. Potassium is generally not required, consult circular for critical soil test. No P is required. No micronutrients are necessary.
Potato- Fertilizer is required at recommended rates for quality as well as yield. Use the same rates as recommended regardless of fertilizer costs.
Extension Soil Specialist, 701-799-2565
