Indian Journal of Agricultural Research

A field experiment was conducted on rice (Oryza sativa L.) for three consecutive rabi seasons of 2007, 2008 and 2009 on Godavari alluvials (Vertic chromusters) at Andhra Pradesh Rice Research Institute, Maruteru, with an objective to revise the existing fertilizer doses of major nutrients for rabi rice in Krishna Godavari delta regions of Andhra Pradesh. Grain yield was increased by 11.5% and 6.3% due to increase in recommended dose of N from 100% (120 kg ha⁻¹) to 125% and 150%. Increase in P & K doses from 100 to 125% (P from 60 to 75 and K from 40 to 50 kg ha⁻¹) also improved grain yield significantly. Agronomic efficiency of N P and K was progressively increased with incremental doses of respective nutrients. Energy use efficiency of K is remarkably high particularly with first increment (4.87) followed by P and N. Highest gross returns, net returns and rupee per rupee invested were recorded with application of NPK @ 210-60-40 kg ha⁻¹. Incremental doses of N, P and K over the recommended dose recorded significant improvement in uptake of respective nutrients. Grain quality, milling characters were significantly influenced by incremental doses of N P & K. While considering the economics, nutrient depletion and quality parameters, application of N @ 180-90-60 kg ha⁻¹ appears to be the most optimum dose for rabi rice in deltaic alluvial soils of Andhra Pradesh.