Integrated nutrient management and LCC based nitrogen management on soil fertility and yield of rice (Oryza Sativa L.)

The experiment was conducted at lowland series of wet lands, International Rice Research Institute (IRRI) Farm, Los Banos, Laguna, Philippines. The rice variety PSBRc 82 was raised during wet season (June – October), and the experiment was laid out in randomized block design with four replications. There were eleven treatments viz., control, recommended NPK fertilizer, -N, -P, -K, LCC 3, LCC 4, LCC 5, 100% N as fresh rice straw, 50% N through rice straw compost and 50% N as poultry manure and 50% N as combined organic manures (RSC + PM). The P and K were applied to all the treatments except -P and –K treatments, respectively. The fertilizer N @ 90 kg ha -1 , P2O5 @ 40 kg ha -1 and K2O @ 60 kg ha -1 were applied in the form of urea, super phosphate and muriate of potash respectively. The application of N at 90 kg level as 50% through RSC + 50% N as PM registered higher available N, P and K contents of soil during different growth stages as compared to the other treatment combinations including recommended NPK fertilizers. The growth and yield attributes were also found to be improved by the above treatment resulting in more grain and straw yield. With regard to N management, LCC 4 and 5 based N applications recorded higher grain yield as a result of higher soil available nutrients during the critical growth stages.