Integrated nutrient management under hybrid rice-(Oryza sativa) hybrid rice cropping sequence

A field experiment was conducted during both rainy (kharif) (2002 and 2003) and summer (boro) seasons (2003 and 2004) at the Regional Research Station, New Alluvial Zone, to study the effect of organic and inorganic sources of plant nutrients applied singly and in combination on rainy season hybrid rice (Oryza sativa L.) and their residual effect on the succeeding summer season hybrid rice, receiving recommended doses of fertilizers. Growth attributes, yield components and grain yields increased with the increase in doses of chemical fertilizers alone as well as in combination with 5 tonnes FYM/ha in both the rainy seasons. Similar trend of result was observed in boro also. In hybrid rice-hybrid rice cropping system, the application of 125% recommended doses of fertilizer along with 5 tonnes FYM/ha during rainy season followed by 100% recommended doses of fertilizer during summer season gave higher grain yield (12.0 tonnes/ha), net return (Rs 15,848/ha) and return/Re investment (Rs 1.34) compared with that of 100% recommended doses of fertilizer in both the seasons (10.45 tonnes/ha) grain yield, Rs 10,004/ha net return and Rs 1.23 return/Re investment. The status of organic carbon, nitrogen, phosphorus and potassium in the soil increased over the initial values after four consecutive croppings where FYM was applied in the rainy season.