Effect of N, P and K fertilizer combination and application rate on yield of Astragalus sinicus L.
氮磷钾肥用量对紫云英产量效应的研究

The effect of nitrogen, phosphorus and potassium fertilization on the yield of Astragalus sinicus L. was investigated in 3414-design fertilization trial. The results show that comparing with no fertilizer treatment (CK), the thirteen fertilization treatments harvest average 21.1 t·hm-2 higher yield, with a yield increase of 135%. Under the fixed combination rates of P25-K2O at 60-60 kg·hm-2, N-K2O at 75-60 kg·hm-2 and N-P25 at 75-60 kg·hm-2, A. sinicus yield significant increase with respective increase in N (N 0~112.5 kg·hm-2), P (P25 0~90 kg·hm-2), K (K2O 0~90 kg·hm-2) application rates. And the highest yield increment rates caused by N, P, K fertilizers are 65.0%, 27.8% and 44.5% respectively. In view of nutrition efficiency, medium application rates of N (N 75.0 kg·hm-2), P (P25 60 kg·hm-2) and a low rate of K (K2O 30 kg·hm-2) are the best application rates. The results also show beneficial interactions among N, P and K. Medium application rates of N (N 75.0 kg·hm-2), P (P25 60 kg·hm-2) and K (K2O 60 kg·hm-2) have synergetic effects on nutrient and yield. The results therefore imply that fertilization significantly increases yield of A. sinicus and different combination and application rates of N, P and K are important factors that influence A.sinicus yield.