Effect of combinations of organic materials and nitrogen fertilizer on growth, yield and nitrogen uptake of rice

Abstract

SummaryIn a 2-year study, the growth and yield of lowland rice increased significantly with the combined use of organic materials and N fertilizer in an acid-lateritic soil. Application of farmyard manure (FYM) or water hyacinth compost (WHC) at 10 t/ha along with paddy straw (PS) at 2·5 t/ha increased grain yield by 28%, similar to the increase given by 30 kg N/ha as fertilizer. The combination of FYM and WHC with or without PS produced yields equivalent to those using 50–60 kg/ha N as fertilizer urea. Uptake of N increased but the recovery of applied N decreased both with the application of organic materials and with increasing N. Organic materials considerably improved the fertility status of the soil, as measured by % C and available N, after crop harvest, whereas N fertilizer made no impact on fertility build-up.