Nutrient uptake, nitrogen use efficiencies, and energy indices in soybean under various tillage systems with crop residue and nitrogen levels after combine harvested wheat

Abstract

A field study was conducted during kharif (rainy season) to study nutrient uptake, nitrogen use efficiencies, and energy indices in soybean under various tillage systems with crop residue and nitrogen levels after combine harvested wheat for two consecutive years. The treatments included three planting methods (Happy Seeder sowing, Straw Chopper + Zero Tillage sowing and Conventional sowing) and four nitrogen levels (0, 75, 100, and 125% recommended nitrogen). Nitrogen (N), phosphorus (P), and potassium (K) uptake by seed and straw were significantly higher in Happy Seeder sowing than Straw Chopper + Zero Tillage sowing and conventional sowing. Agronomic efficiency, physiological efficiency, and apparent recovery were not influenced significantly by different planting methods whereas partial factor productivity, energy output, net energy, energy use efficiency, and energy productivity were significantly higher in Happy Seeder sowing than Straw Chopper + Zero Tillage sowing and conventional sowing. N and P uptake by seed and straw increased significantly from 0 to 75 and 75 to 100% recommended N and similar trend was found in K uptake by seed and straw. Agronomic efficiency, apparent recovery and energy output were increased up to 100% recommended N. However, partial factor productivity was decreased significantly with increase in N levels and physiological efficiency was not influenced significantly by different N levels.