Integrated Nutrient Management in potato based cropping systems for Eastern Indo-Gangatic Plains of India

In order to reduce the use of fertilizers and utilize residual fertility of potato crop, different integrated nutrient management options were examined in two most popular cropping systems viz., rice-potato-onion and maize-potato-green gram of eastern plains at Central Potato Research Station, Patna during 2004_2007. Besides, different recommended dose of fertilizers and 100% organic treatments (farm yard manure to replace recommended dose of N to all crops), other treatments included reduced doses of nutrients to subsequent crops, recycling of crop residue and application of FYM. The maize-potato-green gram sequence gave higher potato yield due to improved soil physical conditions. However, the net return and potato equivalent yield (PEY) was higher in rice-potato-onion system due to higher returns from their component crops. Results indicated the possibility to economize fertilizer in green gram crop but not in onion by replacing 50% NPK through FYM or potato crop residue, when grown on residual fertility of potato. Residue incorporation of leguminous crop had more beneficial effect on subsequent maize crop but same effect of onion residue was not observed on rice. In organic treatment, potato yield was least but steadily increased over the years in both the systems. Soil physical conditions improved in second system as indicated by decreased bulk density and increased organic carbon in sub soil.