Scenarios to Attain the Goals of the Illinois Nutrient Loss Reduction Strategy.

In the Illinois Nutrient Loss Reduction Strategy (NLRS), the IL Environmental Protection Agency calls for a 45% reduction in both nitrate-N (NO3-N) and phosphorus (P) loads leaving the state of IL; additionally, there is a 2025 interim load reduction goal of 15% for NO3-N and 25% for P.  The NLRS clearly demonstrates that meeting the NO3-N and P reduction goals will require near-wholesale adoption of nutrient management practices on agricultural lands across the state of IL.  Following the release of the IL NLRS document - and using the science assessment portion of the strategy as the basis for our analysis - we created 3 interim-goal scenarios and 2 final-goal scenarios that utilized a simpler, more farmer-focused geographic organization and emphasized those practices with the greatest chance of adoption by farmers in IL.  The farmer-guided development of scenarios is a critical first step in understanding the scope of adoption requirements.  Developing scenarios also demonstrates the need to target specific practices to areas of greatest impact, ensuring that practice adoption is most effective.  Focusing on in-field practices and using edge-of-field practices as needed to meet goals, this study demonstrates the importance of cover crops as a primary tool for attaining the NO3-N and P loss reduction goals as well as the value of other in-field and edge-of-field practices.