Effect of split application of potassium on yield and yield attributes of soybean [Glycine max (L.) Merrill]

A field experiment was conducted at Punjab Agricultural University, Regional Research Station, Gurdaspur (Punjab) during kharif 2016–17, to study the effect of split application of potassium on yield and yield attributes of soybean. The experiment was conducted in randomized complete block design with seven treatments applied at sowing and as split application of potassium T₁: Recommended fertilizer dose (12.5 kg N, 32 kg P₂O₅ and no potassium application), T₂: 15 kg K₂O ha⁻¹(at sowing), T₃: 30 kg K₂O ha⁻¹(at sowing), T₄: 60 kg K₂O ha⁻¹(at sowing), T₅: 7.5 kg K₂O ha⁻¹ (at sowing) + 7.5 kg K₂O ha⁻¹ (at flowering), T₆: 15 kg K₂O ha⁻¹(at sowing) +15 kg K₂O ha⁻¹(at flowering), T₇: 30 kg K₂O ha⁻¹(at sowing) +30 kg K₂O ha⁻¹(at flowering). Results revealed that significantlyhigher grain yield (25.2 q ha⁻¹) wasobtained in T₇ (30 kg K₂O ha⁻¹ (at sowing)+ 30 kg K₂O ha⁻¹ (at flowering) as compared to all other treatments but it was statistically at par with the split application of potassium @ 15 kg K₂O ha⁻¹ (at sowing) + 15 kg K₂O ha⁻¹ (at flowering) (T₆) with grain yield of (22.6 q ha⁻¹). Split application of potassium significantly increased soybean grain yield over the basal application with highest benefit cost ratio (7.1). Among the split application of potassium, grain yield of soybean was increased significantly by 15.6% in T₇ treatment over T₅. Split application of potassium was more beneficial than applying full dose of potassium at the time of sowing due to higher number of pods and pod weight plant⁻¹.