Recycling effect of crop residues with chemical fertilizers on physico-chemical properties of soil and rice (Oryza sativa) yield

A field experiment was conducted at the Assam Agricultural University, Jorhat, during the rainy season of 1997 and 1998, to study the recycling effect of crop residues along with chemical fertilizers on physico-chemical properties of soil at harvest and on yield of rice (Oryza sativa L.). Incorporation of crop residues like wheat (Triticum aestivum L emend Fiori & Paol) straw (5 tonnes/ha) or rice straw (5 tonnes/ha) decreased the bulk density and increased the organic matter, cation-exchange capacity, hydraulic conductivity, water-holding capacity of soil than the initial values after 2 years of study and also increased the grain and straw yields of rice Rice straw-incorporated treatment did not show significant difference with wheat straw-incorporated treatment. Increasing levels of NPK applied in rice increased grain and straw yields and did not show any significant effect on soil physico-chemical properties.