Crediting Cover Crops and Soil Organic Matter in a Variable Rate Nitrogen Fertilizer Prescription

Crop growth depends on available nitrogen (N) in the soil, much of which comes from mineralization of soil organic matter and other organic residues, such as cover crops. The amount of mineralized N available to a crop depends on several biological and environmental factors such as temperature, moisture, soil texture, the total quantity of organic matter, and the carbon to nitrogen (C:N) ratio of that organic matter.

Because of these factors, mineralized N can vary greatly across different locations and crop management scenarios. Predicting the amount of N mineralization that will occur in any given scenario may allow farmers to make more efficient use of N fertilizer inputs, improving profitability and reducing the environmental cost of excess N fertilization.

This fact sheet describes the process of developing variable rate N credits for cover crops and soil organic matter.

Related Resource

Website: Nitrogen Recommendations for Corn that Credit Cover Crops and Soil Organic Matter

An online web application that allows users to input information about the cover crops and soil at their site and use the equations to develop an N fertilizer recommendation.