DEVELOPING A WEB-BASED FORECASTING TOOL FOR NUTRIENT MANAGEMENT

US and state nutrient management planning provides strategic guidance that, in the best cases, educates farmers and others involved in nutrient management to make prudent management decisions. The strategic guidance provided by nutrient management plans does not provide the day-to-day support required to make operational decisions, particularly when and where to apply nutrients over the short term. These short-term decisions on when and where to apply nutrients can make the difference between whether the nutrients impact water quality or are efficiently utilized by crops. Infiltrating rainfall events occurring on the heels of broadcast nutrient application are beneficial, as they will wash soluble nutrients into the soil where they are used by crops. Rainfall events that generate runoff shortly after nutrients are broadcast will wash off applied nutrients, producing the largest losses of nutrients possible from that site. Our goal is to develop a research driven support tool for nutrient management, the Fertilizer Forecaster, which identifies the relative probability of runoff or infiltrating events in Pennsylvania (PA) landscapes. This tool will support field specific decisions by farmers on when and where to apply fertilizers and manures over 24, 48 and 72 hour periods. Our objectives are to: (1) monitor agricultural hillslopes in watersheds representing four of the five Physiographic Provinces of the Chesapeake Bay basin; (2) validate a high resolution mapping model that identifies soils prone to runoff; (3) develop an empirically based approach to relate state-of-the-art weather forecast variables to site-specific rainfall infiltration or runoff occurrence; (4) test the empirical forecasting model against alternative approaches to forecasting runoff occurrence; and (5) recruit farmers from the four watersheds to use web-based forecast maps in daily manure and fertilizer application decisions. Data from on-farm trials will be used to assess farmer fertilizer, manure, and tillage management decisions before and after conscientious use of the Fertilizer Forecaster, and will help to understand not only the effectiveness of the tool, but also characteristics of farmers with the greatest potential to benefit from such a tool. Feedback from on-farm trials will be used to refine a final tool for delivery to the PA Conservation Commission. We hope that the Fertilizer Forecaster will serve as the basis for state (PA), regional (Chesapeake Bay), and national changes in nutrient management planning. The proposed project is central to the objectives of AFRI's Management of Agroecosystems program area. Specifically, this project develops an innovative management practice that is designed to enhance the services of aquatic ecosystems by improving water quality and enhance the services of terrestrial ecosystems by increasing the efficiency of nutrient use by targeted crops.