Impact of integrated nutrient management on physical and chemical properties of soil under the sweet potato-green gram maize cropping system

The research investigation, titled Integrated Nutrient Management in sweet potato-green gram-maize Cropping System, was conducted at the Research Farm of Tirhut College of Agriculture Dr. RPCAU, Dholi, Samastipur (Bihar) over two cropping seasons, from 2023 to 2024. The experiment was set up in a split-plot design with three main plots and three sub-plot treatments. For sweet potato the main plots having chemical fertilizers namely F1: RDF (100%) - (100:60:100 kg N:P2O5:K2O)/ha, F2: RDF (125%) - (125:75:125 kg N:P2O5:K2O)/ha and F3: RDF (75%) - (75:45:75 kg N:P2O5:K2O)/ha. The sub plots having organic manures namely M1: FYM @ 15 t/ha, M2: Vermicompost @ 7.5 t/ha and M3: No organic manure. The treatments were allocated randomly in each plot. Application of inorganic fertilizers at recommended doses did not significantly affect soil bulk density, water holding capacity, penetration resistance, pH, EC, or organic carbon. Among organic nutrient sources, FYM applied at 15 t ha⁻¹ consistently improved soil physical properties by lowering bulk density and penetration resistance while enhancing water holding capacity. Chemical soil properties also benefited from FYM application, as reflected by lower soil pH and EC and higher organic carbon content.