USE OF ORGANIC MANURE AND FERTILIZER IN RICE (ORYZA-SATIVA) WHEAT (TRITICUM-AESTIVUM) CROPPING SYSTEM FOR SUSTAINABILITY

A long-term field experiment was initiated in 1984 on a sodic soil (pH 8.8 and exchangeable sodium 27%) to study the effect of organic manur es, fertilizers and their integrated use in rice (Oryza sativa L.)-whe at (Triticum aestivum L. emend. Fiori & Paol.) cropping system. During initial years (1984-87) 25-50%, substitution of fertilizers through o rganic sources (Farmyard manure, green-manure and wheat straw) reduced the lice yield by 6-23% compared with 100% fertilizers alone. In the following years, 25-50% N through farmyard manure or prickly sesban [S esbania aculeata (Retz.) Pers.; syn S. cannabina Pers. var cannabina B aker] green-manure along with 50-75% fertilizers to rice gave either e qual or more yield compared with 100% NPK fertilizers (120 kg N/ha, 26 .2 kg P/ha, 33.2 kg K/ha) alone. Farmyard manure and green-manure of p rickly sesban were found superior to wheat straw for grain yield and N PK uptake. The organic source with fertilizers decreased the soil pH, electrical conductivity and exchangeable sodium (%) at lister rate and depleted micronutrient cations (Cu, Mn, Zn, Fe) at slower rate than i norganic fertilizers alone.