Abstract

Two season trials were conducted in the same field during Kharif (May- Sep.) and Rabi (Oct-Feb) seasons of 1999-2000 at wetland farm of Tamil Nadu Agricultural University, Coimbatore in order to assess the performance of scented rice variety Basmati 370 to organic N source. The experiments involved three nitrogen levels viz., 50 (N,), 75 (N) and 100 (N) kg ha and five source combinations viz., 100% organic N 75% through FYM and 25% through Azolla (C,), 100% organic N-75% . through Sesbania rostrata and 25% through Azolla (C), 100% organic N-75% through FYM and 25% through Azolla + 50 kg P,O, +50 kg K,0 ha (C) 100% organic N-75% through Sesbania rostrata and 25% through Azolla 50 kg P,O,+ 50 kg KO ha (C) and 100% inorganic N, P,O, and K,O (C,). Fifteen treatment combinations were tested in a randomized block design replicated thrice. Required quantities of FYM, Sesbania rostrata and Azolla were incorporated in to the soil one week before transplanting of rice as per the treatments. The results revealed significant improvement in growth characters and yield components with higher N levels that ultimately resulted in higher grain yield. The grain yield increase was to the tune of 25 and 45 per cent for 100 kg N ha over 50 kg N ha in kharif and rabi seasons, respectively. Inorganic NPK application produced higher values for growth and yield attributes. Application of 100 per cent inorganic NPK (C) recorded higher grain yield in both the seasons. However, green manuring with Sesbania rostrata along with Azolla and with or without supplementation of inorganic P and K (C, or C,) registered on par values with C..

Keywords: Basmati 370 rice, organic farming, inorganic, growth and yield)