Effect of row spacing and planting density on the yield and quality of Medicago sativa

This report describes the effects of seed sowing rate and row spacing on yield, stem∶leaf ratio and nutrient composition of Medicago sativa cv. Gannong No. 3 grown in the arid desert region of Gansu. Total yield was the highest when row spacing was 20 cm, which was significantly higher than other spacing of 15, 10 cm, and two kinds of wide and narrow row spacing of planting rows. Total yield was also significantly higher at a seeding rate of 16 kg·ha-1 compared to other seeding rates of 20, 24 and 12 kg·ha-1. Crude protein, crude fat, neutral detergent fibre, acid detergent fibre, calcium, and phosphorus contents were 21.89%, 3.59%, 33.69%, 30.98%, 1.34%, and 0.11% at early flowering stage, respectively. Total yield was 3.28 t·ha-1 and the total crude protein content was 21.89%, and both these were significantly higher at 16 kg·ha-1 seeding rate and 20 cm row spacing compared to all other treatments. Therefore, this may be the optimal combination, as it scored the highest in grey relational analysis on the comprehensive evaluation of major nutrients. These results offer valuable guidance for cultivation and management of alfalfa.