Variation in state based manure nitrogen availability approaches
Channel: Livestock & Poultry Environ. Learning Community
Date: 18/05/2015

The full proceedings paper is at: www.extension.org/72815

The phosphorus (P) index is the primary strategy used in nutrient management planning to identify field management strategies and/or manure application strategies likely to lead to excessive risk of P loss.  Current P Indices were developed primarily as strategic planning tools guiding the development of a nutrient management plan spanning one to five years.  In reality, a nutrient management plan should be viewed more as a process than a result.  After completing the initial strategic plan there are tactical adjustments for new information such as new soil and manure tests and changes in crop selection.  Additional assessments are needed when implementing the plan, determining if current weather and soil conditions are appropriate for application.  Many current P Indices require using the soil erosion program RUSLE2 which is then a barrier to the use of these P Indices by anyone except planners with specialized planning.  Such expertise is never available on some farms and unlikely to be available on most farms during tactical and implement phases of the plan.  There has also been suggestions that more complex strategies such as models should replace existing P Indices; this will lead to more complex P loss assessment tools.  Next generation P Indices will be more effective if we consider the capabilities and training of those likely to be making decisions at each critical juncture.  Instead of "the" P Index we need to design a suite of tools that target key decision points.  In each instance a first step of the development process must be defining who the likely decision maker is and what are their skills and training.  We can only succeed if our tools are accessible to those that need to use them.