1. Analysis of 10 Years of N Rate and Timing Work in Oklahoma Winter Wheat

This study was conducted to determine optimum top-dress nitrogen fertilizer rate by location and environment so it may be reproduced in following years. Winter wheat was planted in different locations each year starting in 2009. Each location had a treatment structure consisting of Preplant nitrogen rates ranging from 28.02kg/ac to 224.17kg/ac and top-dress nitrogen rates ranging from 28.02kg/ac to 140.11kg/ac. When top-dressing occurred there was two plots that had sensor based rates that used... S.G. Akin, B. Arnall