Developing an N Management Assessment Tool.

Efficient use of agricultural N requires site-specific application of N management principles to the unique soil-crop-livestock settings of a farm, as influenced by climate.  With concern about N effects on surface, ground and even gulf waters, managing and assessing N effects compared to P is complicated.  The dynamic nature of N with its many loss mechanisms (immobilization, leaching, volatilization and denitrification) greatly complicates assessing effects and  management compared to P which is a primary concern for surface water. Over time agricultural scientists have developed many specific tools and approaches to improve N use efficiency across a wide array of soil resources, cropping systems, tillage regimes, climatic regions and water management systems (rain-fed to irrigated).  Assessing such a wide array of site-specific conditions is further complicated by the required inclusion of large livestock production systems in different regions of the country.  Nutrient inputs from manure needs to be addressed with commercial N sources.  Changes in feed sources, manure management systems, and varying land application practices require assessment.  However, the tools and approaches for efficient N management all share one common theme: improving N efficiency should focus on management, i.e. educating and training the producer. A N management assessment program (NMAP) will be described that seeks to inventory current N management practices on a site-specific basis and compares them to current accepted practices of good N management. This tool is intended to be a simple producer inventory (possibly similar to Farm-A-Syst)  that can be used to identify areas within a farm or on a whole-farm basis that could benefit from enhanced N management.  An end product would also suggest site-specific techniques to improve N use efficiency on individual N management units.