Investigation of Small Grain Response to Various Applications of Nitrogen, Phosphorus, and Potassium on Several Kansas Soils

Abstract

AbstractFour wheat and three oat fertilizer experiments were established at various locations in the eastern half of Kansas for the crop year 1950–51. Objectives of these experiments were to obtain information (1) relative to the best time, rate, and method of applying nitrogenous fertilizers to wheat and oats, and (2) concerning the use of phosphorus and potassium in combination with various rates of nitrogen.Each experiment consisted of four factorially designed randomized blocks. Rates of nitrogen used were 0, 25, 50, and 100 pounds per acre; rates of available phosphoric acid were 0 and 50 pounds per acre; and rates of potash were 0 and 25 pounds per acre. Chemical analyses of the soils were made. Yield data were analyzed statistically and comparisons were made. Significant yield differences between treatments were obtained for each experiment.Greatest increases in yield of wheat accompanied the heaviest applications of nitrogen with the single exception of one location which recently had been in alfalfa. The application of both phosphorus and potassium increased the yield of wheat appreciably at this location, most of the increase being due to phosphorus. The application of potash increased the yield appreciably where no ammonium nitrate was supplied.Significant increases in yield of oats were obtained at each location following the application of 50 pounds per acre of nitrogen. The inclusion of phosphorus and potassium in the fertilizer did not affect oat yields very much.The time of application of nitrogen generally had little influence on yields of either wheat or oats. From an economical standpoint, application of all the nitrogen at seeding time might be preferable.