Effect of different nutrient management practices on soil available macronutrients (NPK) in rice-wheat cropping system

Rice-wheat system has played a major role for raising food grain production to make the country self-sufficient. However, its sustainability has been questioned in view of decline in crop yields and factor productivity of fertilizers. Soils of Trans-Gangetic Plains (representing Punjab and Haryana) and Upper Gangetic Plains (representing Delhi and Western UP) plain suffering from production fatigue manifesting in terms of declining soil organic matter, multi-nutrient deficiencies and diminishing factor productivity. The excess mining of nutrients by the crops is more than their replenishment with fertilizer. The field experiment under rice and wheat crop was established at CCS HAU, College of Agriculture, Kaul farm during 2021-22 and 2022-23. The experiment was planned in a split-plot design. The study included four main plot treatments and four sub plot treatments. The grain yield of wheat and rice was observed highest for 125% RDF, followed by 100% RDF, 75% RDF and lower in control under rice-wheat cropping system. Among main plot treatments, it was found that FYM+FYM showed lower grain yield of wheat and rice crop, followed by RDF (B)+GM, RS+RDF (B) and maximum was in RDF+RDF treatment. It was observed that the available nitrogen was increased by 5.19 to 16.6% in organic treatments, 7.5 to 16.2% in fertilizer treatments over the initial value of available nitrogen (138.57 kg ha^-1). The data revealed that organic carbon fraction increased where organic source was applied with RDF of N, P and K fertilizer.