A Consultant's Perspective on Efficiency Improvements with Precision Nutrient Management

Nutrient management, especially regarding nitrogen (N) fertilizer, is among the most inexact and costly agronomic decisions that growers face in modern corn production.  Because soil N varies dynamically in response to interactions between soils, weather and crop use, the optimal N application rate for any year or location can vary widely. As a result, N is often unintentionally over and under applied at any given location or in any given year, reducing profitability and in some cases leading to environmental issues.  The major managerial causes for inefficient N management include: (1) poor synchrony between timing of large doses of pre-plant N application and crop demand, (2) field-uniform applications to spatially variable landscapes that commonly vary in crop N need, and (3) failure to account for year to year influences on crop N needs. The key to optimizing tradeoffs amongst yield and profit is less reliance on preplant significant applications of N at field uniform rates and greater dependence on in-season applications of spatially variable N rates. This will achieve better synchrony between soil N supply and crop demand and more optimal utilization of applied fertilizer.  This presentation will provide a brief overview of commercial precision technologies for improving N management, some personal experiences with the tools, and some perceived challenges to their adoption.