Integration of Fertilizer Nitrogen, Farmyard Manure and Multi-strain Microorganisms for Sustainable Production of Rice-Wheat System

Use of high rates of commercial nitrogen (N) fertilizers over the years has resulted in adverse effects on soil and environment health. Integrated use of fertilizer N and organic N sources is expected to reduce the N losses and improve N use efficiency. The present field experiment was conducted for two years to evaluate the effects of commercially available multi-strain inoculant ‘Fertimine’ and farmyard manure (FYM) applied at variable rates of fertilizer N on the nutrition of rice-wheat system. Four treatment combinations of FYM (15 t ha⁻¹, fresh weight) and fertimine were applied to main-plots and four N levels to sub-plots in factorial split-plot design. In the absence of fertimine and FYM, significant increase in rice yield was observed up to 120 kg N ha⁻¹ during first season and 80 kg N ha⁻¹ during second season. The application of FYM and fertimine significantly increased mean grain yield of rice by 12 and 5 per cent over no FYM and fertimine, respectively. Significant interaction effect of fertimine and fertilizer N observed on rice grain yield suggested that fertimine significantly increased the rice yield at low rates of fertilizer N. While fertilizer N and FYM caused significant increase in the total uptake of N, P and K in rice, fertimine showed significant increase in total P uptake only. The FYM applied to rice showed significant residual effect on the yield and total N, P and K uptake in the subsequent wheat. Application of FYM significantly improved the soil chemical and biological properties after two cycles of rice-wheat rotation.