A variable rate nitrogen applicator based on optical reflectance measurements was developed to increase profits in wheat production by reducing the cost of production or by increasing grain yield. This paper determines if yields and profits from the variable rate treatments are significantly...

Past research about the efficiency of nitrogen application in winter wheat (Triticum aestivum L.) based on source and timing has produced inconsistent results. The majority of the literature used data from few locations over short time periods. This study used a unique data set of yields and...