Direct and residual effects of fertilizers and biofertilizers on yield, nutrient uptake and economics of groundnut (Arachis hypogaea)-rice (Oryza sativa) cropping system

摘要

A two-year field experiment was conducted during the winter (rabi) and rainy {kharif) seasons of 2010-12 at Deodhe, Ratnagiri (IViaharashtra), to study the direct and residual effects of different doses of fertilizers and biofertilizers on yield, nutrient uptake and economics of groundnut {Arachis hypogaea L.)-rice (Oryza sativa L.) cropping system. Increasing dose of fertilizers up to 125% recommended dose of fertilizers (RDF) significantly increased pod yield by 79.7% and haulm yield by 63.3% of groundnut over the control. Uptake of N, P and K by groundnut also improved significantly with successive increase in doses of fertilizers up to 125% RDF. Succeeding rice showed significant response to residual fertilizer levels up to 100% RDF in grain yield and up to 125% in straw yield and registered 16.9 and 25.4% increase over the control, respectively The N, P and K uptake by succeeding rice and total NPK uptake, rice-grain equivalent yield, production efficiency, net returns and benefit: cost ratioin groundnut-rice cropping system also improved significantly with increase in doses of fertilizers up to 125% RDF applied to groundnut. The crop inoculated with biofertilizers (Rteo>/um+phosphate-solubilizing bacteria) recorded significantly higher pod(1.74 t/ha) and haulm yields (3.64 t/ha) of groundnut and grain (5.34 t/ha) and straw yields (5.52 t/ha) of succeeding rice over the control. Inoculation of groundnut with biofertilizers significantly increased N, P, K uptake by groundnut and succeedingrice (except N uptake by rice straw) as well as total N, P and K uptake (393.1 kg/ha), rice-grain equivalent yield (9.92 t/ha), net returns (66.8x10~3/ha) and benefit: cost ratio (2.01) in groundnut-rice cropping system over no inoculation. This treatment also recorded the maximum production efficiency of the system (38.8 kg/ha/day). Rice crop responded significantly to each higher level of fertilizer up to 125% RDF (direct) in terms of grain and straw yields as well as N, P and K uptake. Application of125% RDF to rice recorded significantly higher total N, P and K uptake (447.1 kg/ha), rice-grain equivalent yield (10.89 t/ha), production efficiency (42.6 kg/ha/day), net returns (78.3x107ha) and benefit: cost ratio (2.17) in groundnut-rice cropping system.