Effect of Applied Phosphorus on the Yield and Nutrient Uptake by Soybean Cultivars on Acidic Hill Soil

Abstract

In a three years experiment, conducted on acidic soil, four varieties of soybean [Glycine max (L) Merril] were tested to see their performance under different regimes of applied Phosphorus. The highest number of pods was given by the cultivar Bragg, followed by Punjab-1, Durga and JS-89-21. A similar trend was observed in the number of filled pods. On an average, the cultivar, Punjab-1, gave the maximum harvest index, followed closely by Bragg. Both the cultivars, Durga and JS-89-21, had lower harvest index. The application of P fertilizer significantly increased the harvest index up to 60 kg·P·ha^–1. The Highest yield of grains was given by the variety ‘Bragg’ (1630 kg·ha^–1), followed by Punjab-1, JS-89-21 and Durga, which gave the yields of 1510, 1470 and 880 kg·ha^–1, respectively. Highest N, P and K removal was found by the cultivar Bragg, followed by Punjab-1, JS-89-21 and Durga cultivars. The uptake of nutrients was significantly related to the total biomass produced by a cultivar (r = 0.8125), showing a yield predictability of 66.0%. The increase in uptake of N, P and K, respectively, with the application of 60 kg·P·ha^–1 over no P was; 245.3, 159.4 and 158.3% in case of Bragg, 101.5%, 73.8% and 44.6% in case of Durga, 182.2%, 70.6% and 63.8% in case of JS-89-21 and 164.7%, 80.0% and 97.4% in case of Punjab-1. A significant increase in soil available P was found in the plots where it was applied @ 60 kg·ha^–1 continuously for three years.