Growth and yield of soybean as influenced by of graded nitrogen and phosphorus dose or under rainfed situations

Abstract

A field experiment was carried out during kharif 2015 with thirteen ratios of nitrogen and phosphorus fertilizers with constant potassium level (25 kg K2O ha-1) on soybean cultivar DSb 21 at MARS, UAS, Dharwad. The seed yield increased due to increasing N/P ratios up to 0.78. The treatment receiving N/P fertilizer ratio of 0.70 (basal application of 18 kg N, 46 kg P2O5, 25 kg K2O ha-1 + foliar application of nitrogen@7 kg N ha-1 at initiation of flowering and foliar application of nitrogen@7 kg N ha-1 at 15 days after first foliar spray) recorded significantly higher seed yield (3217 kg ha-1), total number of pods plant-1 (47.57), 100 seed weight (15.40 g) and seed weight plant-1 (18.31 g). This treatment also recorded significantly higher leaf area plant-1 (12.62 dm2), leaf area index (4.21) and total dry matter production (34.15 g)