User capabilities and next generation phosphorus (P) indices


The phosphorus (P) index is the primary approach to identify field management strategies and/or manure application strategies likely to lead to excessive risk of P loss. It has been over 40 years since the first research connecting agronomic P management and water quality and over 20 years since the initial publication defining a P Index.…

Estimation of phosphorus loss from agricultural land in the Heartland region using the APEX model: a first step to evaluating phosphorus indices


Phosphorus (P) indices are a key tool to minimize P loss from agricultural fields but there is insufficient water quality data to fully test them. Our goal is to use the Agricultural Policy/Environmental eXtender Model (APEX), calibrated with existing edge-of-field runoff data, to refine P indices and demonstrate their utility as a field assessment tool capable of protecting water quality.…

Software and Web-Based Resources for Nutrient Management

Why Utilize Tools for Nutrient Planning?

The process of nutrient management planning can be complex and time consuming. Doing a good job requires:

  • collecting and organizing extensive information about a farm;
  • making a diverse series of decisions and calculations about crops, fertilizer and manure management; and
  • communicating the completed plan to a multiple audiences including the farmer.