International Journal of Plant & Soil Science

The field experiment was conducted at S.V. Agricultural College Farm, Tirupati during rabi (maize) summer (blackgram) and kharif (groundnut) seasons of 2019-20 with a view to study the direct and residual effects of integrated use of inorganic and organic sources of N and P on performance of maize - blackgram- groundnut cropping sequence in terms of yield. In this experiment, Ten treatments viz. control, fertilizers applied at 50, 75 and 100% of the recommended dose (N240P80K80), N240 only, P80 only, FYM (@ 5 t ha⁻¹) applied alone, and in combination with 100%,75% and 50% recommended NPK were applied to maize. These treatments were evaluated in comparison to no-fertilizer and manure controls. Blackgram was produced after maize without the use of fertilizer or manure. It was allowed to grow till maturity, and after two pickings, the stover was incorporated into the soil. During succeeding rabi season on the same field black gram was grown for which each main plot treatment of RBD was split into three sub plot treatments with three levels of recommended dose of fertilizers viz., S1 (control), S2 (75% RDF) and S3 (50% RDF) resulting in ninety treatment combinations replicated three times in split plot design. The results revealed that the total N and P uptake in maize varies from 56 - 142 kg/ha and 8.28 - 22.12 kg/ha, in blackgram it varies from 86 – 173 kg/ha and 11.1 – 22.7 kg/ha and in groundnut 75.8 – 126.9 and 9.5 -20.0 kg/ha respectively. The maximum nutrient concentration and uptakes in case of all treatments was found in INM treatments and lowest in T₁ (Control).