Integrated nutrient management in rice (Oryza sativa)-rice crop sequence

Abstract

A field experiment was conducted during the rainy and winter seasons of 1988, 1989 and 1990 to study the integrated nutrient management through organic and inorganic sources of fertilizer in a rice (Oryza sativa L.)-rice crop sequence. Grain yield of rainy-season rice was higher under 100% recommended dose of NPK fertilizer supplied through either inorganic source alone or 75% through inorganic and 25% through organic source. Application of NPK at suboptimal aose, i.e. 75% and 50% of recommended NPK dose, or following farmers practice reduced the grain yield significantly. The total land productivity in rice-rice crop sequence was higher when both rainy- season and winter-season rice received 100% recommended dose of NPK fertilizer. For the rainy- season rice, the uptake of the nutrients NPK was more when 75% of the fertilizer were applied as inorganic and 25% as organic sources, whereas in winter s&on maximum uptake of the nutrients by rice was recorded when 100% of NPK was supplied as inorganic source.