Pre-seeding fertilizer tips for farmers
Clain Jones, MSU Extension Soil Fertility Specialist Presented at the Montana Agricultural Business Association last winter in Great Falls. The majority of the presentation contained a variety of fertilizer tips to help producers prepare for the upcoming seeding season. In addition, information for this article was taken from the Fertilizer Guidelines for Montana Crops (EB161), which is available at the Chouteau County Extension office.
• MSU Extension has an on-line tool designed to assist producers in determining the optimal N rate. The online-tool is located at http://www.sarc.montana.edu/php/soiltest/.
• South Dakota State University has an on-line tool designed to assist producers in determining safe seed-placed rates. The on-line tool is located at http://seed-damage-calculator.herokuapp.com/.
• Fall soil tests can lead to over or under fertilized fields because soil nitrate can increase or decrease from November to April.
• The historical average available N rate guideline at 2% soil organic matter for dryland winter wheat is 2.6 pounds of N/bushel @ 12.5 protein. If soil organic matter is less than 1%, add 15-20 pounds of Nitrogen per acre. If soil organic matter is greater than 3%, reduce the Nitrogen rate 15-20 pounds per acre.
• For producers who are practicing variable rates of Nitrogen in the field, the simplest process is to divide the field into low, medium and high productivity.
• An annual legume like a pulse crop will contribute around 10 pounds of available Nitrogen per acre to the soil. Producers are advised to adjust fertilizer rate down 10 pounds.
• Stubble has a high carbon to Nitrogen ratio. As a result, Nitrogen rates need to be increased in heavy stubble areas.
• When using row spacing wider than 7 inches, do not apply any urea with the seed.
• A 30 bushel per acre yield potential requires 78 pounds per acre of available Nitrogen.
• A 40 bushel per acre yield potential requires 104 pounds per acre of available Nitrogen.
• A 50 bushel per acre yield potential requires 130 pounds per acre of available Nitrogen.
• A 60 bushel per acre yield potential requires 156 pounds per acre of available Nitrogen.
• A 70 bushel per acre yield potential requires 182 pounds per acre of available Nitrogen.
• An 80 bushel per acre yield potential requires 201 pounds per acre of available Nitrogen.
• A 90 bushel per acre yield potential requires 234 pounds per acre of available Nitrogen.
