Productivity, nutrient uptake, energy indices and profitability of soybean (Glycine max) as influenced by planting methods, Bradyrhizobium and plant growth promoting rhizobacteria

A field experiment was conducted during rainy season (kharif) of 2014 and 2015 at Punjab Agricultural University, Ludhiana, Punjab to study the effect of planting methods, viz. Happy seeder sowing, straw chopper + zero tillage sowing and conventional sowing and biofertilizers, viz. Bradyrhizobium, plant growth promoting rhizobacteria (PGPR) and Bradyrhizobium + PGPR on nutrient uptake, energy indices, productivity and profitability of soybean [Glycine max (L.) Merrill). Results showed significantly higher seed yield, gross returns, net returns and benefit: cost ratio with happy seeder sowing as compared to straw chopper + zero tillage sowing and conventional sowing. N, P and K uptake by seed and straw were significantly higher in happy seeder sowing than straw chopper + zero tillage sowing and conventional sowing. Happy seeder sowing recorded the lowest energy input and the highest energy-output, net energy, energy-use efficiency and energy productivity. Seed inoculation with Bradyrhizobium and/or PGPR did not influence N, P and K uptake by seed and straw and energy indices significantly. However, combined inoculation of Bradyrhizobium and PGPR recorded the highest gross returns, net returns and benefit: cost ratio. Zero tillage with happy seeder sowing was found promising with the highest net returns and energy-use efficiency.