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Using Adapt-N

On-farm strip trials on Long Island, NY: Above: A = 93 lb N, G = 159 lb NBelow: A = 132 lb N, G = 175 lb NAG

AGIncorporating Local Weather and Soil Variation in Adaptive Nitrogen Management: Validating the Adapt-N Tool for On-Farm Sidedress RecommendationsBianca N. Moebius-Clune*, Harold M. van Es, Jeff M. Melkonian, Art DeGaetano, Laura Joseph, Robert R. Schindelbeck, Shannon Gomes*bnm5@cornell.edu, Department of Crop and Soil Sciences, Ithaca, NY, Cornell UniversityConcerns 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 variablesLarge NO3- leaching losses contribute to hypoxia in estuariesN2O from denitrification makes up largest fraction of greenhouse gas emissions associated with U.S. agricultureLosses occur in wet spring/early summer or following the cropping season if excessive N was applied, or if drought limited crop N uptakeAdapt-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:

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 needsUses high resolution climate data (daily precipitation and temperature) on a 4x4 km gridReadily 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 Structurehttp://adapt-n.cals.cornell.edu

High Resolution Weather DataCurrently available for Northeast & Iowa; entire Eastern US in 2012Enables field-scale adaptationAllows 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 rateResults page of interface provides in-season N recommendation and graphs of soil, crop and climate simulation:Cumulative N mineralization from organic sourcesCumulative N uptake by crop Cumulative total N losses Cumulative N Leaching Losses Nitrate-N in top 12 inches Inorganic N in the full Root ZoneGrowing Season Daily RainfallGrowing Season Cumulative RainfallPost-Emergence Growing Degree DaysCorn vegetative growth stageGrowing season average temperaturePreliminary Results of On-Farm ValidationIn 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 15 - 130lb/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 yieldA 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

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