In his latest update of the Fertilizer Guidelines for Agronomic Crops in Minnesota, Dan Kaiser, University of Minnesota Extension nutrient management specialist, offers valuable insights on maximizing corn crop yields while balancing economic considerations. By tailoring nitrogen application rates and leveraging real-world data, growers can achieve optimal results.
Dan Kaiser advises growers to use the fertilizer rate guidelines as a starting point, acknowledging that fertility requirements can vary significantly within and across fields. The Nitrogen Smart program encourages farmers to adjust rates based on pre-plant nitrate tests (PPNT) and on-farm research to fine-tune nitrogen application.
While many growers focus solely on maximum yield, Dan suggests considering the "marginal return" of each pound of applied nitrogen. The Maximum Return to Nitrogen (MRTN) approach helps determine the point where the cost of nitrogen fertilizer outweighs the additional yield it provides. By utilizing the regional corn N rate calculator, farmers can adapt to changing fertilizer and crop prices to maximize profit.
Despite rising corn yields, nitrogen rates have not kept pace due to varying soil needs. Factors like residue and wet conditions influence nitrogen requirements in corn-following-corn and corn-following-soybean fields. Dan highlights the importance of understanding soil organic matter and its relation to nitrogen needs, while also addressing concerns about water quality and nitrogen loss.
Dan emphasizes nitrogen best management practices, ensuring optimal nitrogen application prevents excess nitrate in soil without sacrificing yield potential. Reducing nitrogen rates below economic optimum doesn't significantly reduce residual soil nitrogen. Farmers must balance profitability and environmental stewardship.
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Categories: Minnesota, Crops, Corn