Land Grant University Fertilizer Recommendations: An Overview and Call to Action.

Land grant university fertilizer recommendations have served as the basis for nutrient applications made to agricultural fields across the US for decades. However, the wide range of fertilizer recommendations for the same crop, yield goal and soil test values from one state to another is almost frightening, as fertilizer costs can more than double by crossing a state line. In addition, very few states provide fertilizer management recommendation options appropriate for both leased and owned land, and these recommendations or guidelines are usually rigid and insensitive to producer goals and resources. How credible is our advice to farmers in the real world? Soil and climate variables do not change abruptly at our state boundaries, so why do our fertilizer recommendations? Is it time to consider alternative and more consistent approaches to making fertilizer recommendations based on something other than state boundaries? In this presentation we will show how different fertilizer recommendations can be and provide a potential framework for improving them.