Using Adapt-N On-farm strip trials on Long Island, NY: Above: A = 93 lb N, G = 159 lb N Below: A = 132 lb N, G = 175 lb N AG AG Incorporating Local Weather and Soil Variation in Adaptive Nitrogen Management: in Adaptive Nitrogen Management: Validating the Adapt-N Tool for On-Farm Sidedress Recommendations Validating the Adapt-N Tool for On-Farm Sidedress Recommendations Bianca N. Moebius-Clune *, Harold M. van Es, Jeff M. Melkonian, Art DeGaetano, Laura Joseph, Robert R. Schindelbeck, Shannon Gomes * Department of Crop and Soil Sciences, Ithaca, NY, Cornell University Concerns with Nitrogen in Corn Corn is the largest consumer of N in US (~ $5 Billion/yr) N use efficiency is often less than 50% Current predictions of annual corn N fertilizer needs are generalized and imprecise (+ or - 40%) due to dynamic, complex and locally- specific interactions among weather, soil and management variables Large NO 3 - leaching losses contribute to hypoxia in estuaries N 2 O from denitrification makes up largest fraction of greenhouse gas emissions associated with U.S. agriculture Losses occur in wet spring/early summer or following the cropping season if excessive N was applied, or if drought limited crop N uptake Adapt-N: a tool for adaptive N management in corn A computational tool that farmers, crop consultants, and planners can use to develop precise nitrogen recommendations for fields adjusted for local weather, soil characteristics, and management practices. Adapt-N has three important components: 1)Well-validated Precision Nitrogen Management (PNM) dynamic simulation model simulates locally-specific daily soil C and N transformations, water transport and corn N uptake, to calculate in-season N fertilizer needs 2)Uses high resolution climate data (daily precipitation and temperature) on a 4x4 km grid 3)Readily accessible, server-based web-interface allows farmers to define field-specific management and soil test info to run simulations from anywhere with internet access. No software is needed, and the tool even works from tablets and smart-phones. Adapt-N Structure High Resolution Weather Data  Currently available for Northeast & Iowa; entire Eastern US in 2012  Enables field-scale adaptation  Allows for field-scale N management adaptation to climate change Adapt-N Inputs Adapt-N Outputs N deficient N excess for PSNT equivalent, divide by 4 Sample Strip Trial Layout: Spatially Balanced Complete Block Design (after van Es 1993). A = Adapt-N recommended N rate; G = grower practice N rate ‘Results’ page of interface provides in-season N recommendation and graphs of soil, crop and climate simulation: Cumulative N mineralization from organic sources Cumulative N uptake by crop Cumulative total N losses Cumulative N Leaching Losses Nitrate-N in top 12 inches Inorganic N in the full Root Zone Growing Season Daily Rainfall Growing Season Cumulative Rainfall Post-Emergence Growing Degree Days Corn vegetative growth stage Growing season average temperature Preliminary Results of On-Farm Validation  In 45 replicated on-farm strip trials in New York and Iowa, grower applications of N to silage, grain and sweet corn exceeded rates recommended by Adapt- N by lb/acre in almost all cases.  In a few locations where excessive rainfall occurred, Adapt-N recommended higher rates.  Two NY trials with lower Adapt-N rates show no statistically significant differences in yield  A few trials show visible deficiencies due to lower Adapt-N rates.  Harvest data are still being collected.  Strip trial data will be used to further calibrate the model this winter.  A second set of strip trials will be conducted in 2012 Left: On-farm strip trial in IA. A = 100 lb N, G = 150 lb N