IMPROVING YIELD IN ALFALFA SEED STANDS WITH BALANCED FERTILIZATION

Field experiments were conducted from 2000 to 2007 on three-year or older alfalfa stands grown for seed production at various sites in northeastern Saskatchewan to determine the influence of balanced application of phosphorus (P), sulfur (S), or potassium (K) fertilizers on seed yield and longevity of alfalfa stands. Survey trials were also conducted to determine the possible reasons for low seed yields on some alfalfa seed fields by comparing “bad” (i.e., low alfalfa seed-yielding) and “good” (i.e., high alfalfa seed-yielding) areas within alfalfa seed stands. The results of alfalfa seed field survey trials suggest that poor seed yields in “bad” areas compared to “good” areas in most alfalfa stands were due to nutrient deficiencies and/or a soil fertility imbalance, as evidenced by soil tests for available nutrients. The findings of field research experiments indicated that application of P, K, or S fertilizer nutrients was essential to obtain optimum seed yield in most cases under normal soil moisture c...