Abstract

A field experiment was conducted to determine the effect of Phosphorus (P) application (0, 8.5, 17.0 and 25.5 kg ha^-1) and Potassium (K) application (0, 37.5, 75.0 and 112.5 kg ha^-1) on growth and yield of soybean (Glycine max (L.) Merr.) in relay strip intercropping system. The plant height, stem diameter, branch number and leaf area increased at first and then decreased with the increment of P application, but the performance of lodging rate showed oppositely. By applying K from 0 to 112.5 kg K ha^-1, plant height, lodging rate, unfilled pod ratio, and 100 seeds weight were significantly reduced, while pods per plant, seeds per pod, and harvest index remarkably increased. The Highest benefit in growth and seed yield was obtained at rates of 17.0 and 112.5 kg ha^-1 for P and K, respectively. Application of 17.0 kg P ha^-1 at the rate of 112.5 kg K ha^-1 gave 18.5, 13.7, and 4.0% higher seed yield than its application at rates of 0, 37.5, and 75 kg K ha^-1, respectively. In conclusion, the findings suggested that the combination of P (17.0 kg ha^-1) and K (112.5 kg ha^-1) can maximize productivity of soybean in the relay strip intercropping system.

Keywords: Phosphorus, potassium, growth, yield, relay strip intercropping soybean.