Screening of fertilization combination for alfalfa in Beijing area

The orthogonal experimental was designed to screen the best fertilizer combination and recommend fertilizer rate of nitrogen, phosphorus, potassium fertilizer for alfalfa in Beijing area. The results showed that the forage yield, growth rate and regeneration rate of alfalfa significantly increased using nitrogen, phosphorus and potassium fertilizers in the areas with shortage of nitrogen and phosphorus fertilizers. The growth rate and regeneration rate of alfalfa with fertilization treatments were significantly higher than that without fertilization treatment (P0.05). The forage yield increased by 17.31% to 29.28% which showed the significant effects of fertilization. The fertilization combination with the highest yield increase rate as N 50 kg·ha-1＋P 140 kg·ha-1＋K 160 kg·ha-1. However, the orthogonal analysis results showed that the fertilization combination with the highest yield increase rate was N 100 kg·ha-1＋P 140 kg·ha-1＋K 160 kg·ha-1. After comprehensive analysis, the recommendation fertilizer rate was N 50～100 kg·ha-1, P 140 kg·ha-1 K, and 160 kg·ha-1 which had the highest forage yield of alfalfa on those areas with shortage of nitrogen and phosphorus fertilizers.