Long-Term Organic Amendment Application Improves Soil Fertility Status, Nutrient Accumulation and Crop Productivity Under Rice-Wheat Cropping System

The major issue in modern agriculture is long-term sustainability. Nutrient management by integrating organic manures and inorganic fertilizers may play a vital role in improving and sustaining crop productivity. A long-term field experiment (since 1984) comprising 11 treatments with different combinations of inorganic and organic fertilizers such as farm yard manure (FYM), wheat cut straw (WCS) and Dhaincha (Sesbania aculeata L.) as green manure (GM) was conducted to evaluate their effects on crop yield, nutrient accumulation and soil fertility status under a rice - wheat cropping system. The maximum grain yield of wheat was recorded in T-6, i.e. 50% recommended dose of fertilizers (RDF) + 50% nitrogen through FYM in rice and 100% RDF in wheat (4291 kg ha(-1)) as compared to chemically fertilized plots T-5, i.e. 100% RDF in both rice and wheat (3441 kg ha(-1)). The application of organic manures in combination with chemical fertilizers reduced soil pH and bulk density from 7.40 to 7.23 and 1.49 to 1.37 g cm(-3), respectively. Soil organic carbon (SOC), available soil nutrients and nutrient accumulation by crop were higher in integrated nutrient management-treated plots as compared to control. A positive and significant correlation was observed between SOC and available soil nitrogen (r = 0.987), phosphorus (r = 0.913) and potassium (r = 0.921). The results clearly suggest that integrated use of chemical fertilizers and organic manures on a long-term basis improves soil fertility and crop productivity with the potential to enhance soil sustainability