Soil and Alfalfa Plant Characteristics as Affected by a Decade of Fertilization¹

Abstract

Abstract The 10‐year field study indicates annual top‐dressings of K are needed to maintain a dense stand for high yields of quality alfalfa on sloping Port Byron silt loam. Total yield increases were related to total quantities of P or PK applied, with largest increases obtained from annual K with P top‐dressings. Contents of P and K in 10‐year‐old alfalfa were related to quantities of these elements applied. The P and K concentrations generally were highest in the third cutting and lowest in the second. There appeared to be little movement of P below the surface 3 inches and little movement of K below 6 inches in Port Byron silt loam during the ten years of the experiment.