ON-FARM EXPERIMENTS ON INTEGRATED NUTRIENT MANAGEMENT IN RICE-WHEAT CROPPING SYSTEMS

Abstract

On-farm experiments were conducted between 1990–91 and 1996–97 in the Indian districts of Jalandhar (Punjab) and Ghazipur (Uttar Pradesh), on rice-wheat cropping systems. The aim was to compare yields and net returns from three treatments: (i) farmers' nutrient management practices; (ii) integrated use of organic manures and fertilizer; and (iii) NPK fertilizer inputs alone. Productivity of the rice-wheat systems, in terms of grain yield per unit area, was greater in Jalandhar district than in Ghazipur district. In Jalandhar, a high productivity zone, greatest yields were achieved with integrated use of green manure and fertilizer NPK inputs, while in Ghazipur, a low productivity zone, yields were highest with inputs of fertilizer NPK alone. Increases in yield due to these improved practices, over farmers' practice, were 6.98% in Jalandhar and 46.6% in Ghazipur. At both locations, net returns were greater with the use of fertilizer NPK alone. However, benefits from NPK alone over farmers' practice were 6.96% in Jalandhar and 79.6% in Ghazipur. After 11 years of a long-term experiment, at Ludhiana (Punjab) and Faizabad (Uttar Pradesh) soil organic-C and available phosphorus contents have increased, and available potassium content decreased compared with the initial levels.