EFFECT OF BROADCAST PHOSPHORUS ON ALFALFA YIELD AND QUALITY

A 3 year old stand of 'Cargo' alfalfa with no previous fertilizer application was evaluated for response to phosphorus and a phosphorus-magnesium mix.;Application was made on February 1, 1986 and yield was measured at approximately 1 month intervals until August 6, 1986. Yield increases of 13% in dry matter production were realized with phosphate application. Average yield for the entire growing season was not significantly different among treatments. The treatments did significantly increase plant tissue concentrations of phosphorus. Broadcast application does appear to be a viable way of supplying the plants with additional phosphorus for plant nutrition. Low soil phosphorus levels were not the critical limiting factor to increased alfalfa yield in this experiment. (Abstract shortened with permission of author.);Treatments consisting of 33 kg/ha of 0-45-0 dry phosphate granules, and a 33 kg/ha of 0-45-0 plus 44 kg/ha Sulfomag combination were broadcast on a growers field in Brawley, California.