Influence of Fertilizers on the Crude Protein Yields of Bromegrass Pasture in the Matanuska Valley

Abstract

AbstractCrude protein yields of bromegrass pasture were markedly increased by nitrogen fertilizers. This conclusion is based on field trials in the Matanuska Valley of Alaska during 1949, 1950, and 1951. A split‐plot factorial design was used to compare five rates of nitrogen fertilization, spring versus summer nitrogen applications, and three levels of phosphate‐and‐potash applied in a fixed ratio.Each increment of nitrogen, including the highest level (128 pounds of nitrogen per acre) produced highly significant increases in protein yields. Greatest production amounted to 636 pounds of crude protein per acre as compared to unfertilized plots which produced only 100 pounds. Sixfold increases were obtained from heavy fertilization which is economically feasible under present conditions.Significant nitrogen × phosphate‐potash interactions were observed. Early season protein yields are usually increased by phosphate‐potash applications while later clippings are generally not benefitted.Stage of maturity when grazed also determines crude protein yields which are the greatest during the early flowering stage.