Effect of fertilizer, row spacing and clipping on alfalfa seed

Quick starting of seedlings and better plant survival were the primary results of fertilization for alfalfa seed production, according to three years of trials at the West Side Field Station, Fresno County. Alfalfa seed yields were not influenced by fertilizer applications (singly or in com- binations) of nitrogen, phosphorus, potash, gypsum or minor elements when used on established stands. Plant distribution and density of stands were definitely shown to be factors in alfalfa seed setting. Thinning within the row was found beneficial, and the best three-year average yields were in thinned stands where rows were spaced 24 to 48 inches apart. The indicated dates to cut back stands to start a seed crop were from April 10 to 20 at this location.

Nitrogen and phosphorus (15 to 20 units of each) applied, at or before planting, and slightly below or to one side of the drilled seed, were beneficial in establishing stands, but usually failed to show an increase in yield.