Physicochemical transformations of soil under different rice establishment methods and residue management practices in rice-rice system

Mechanized harvesting often leads to residue burning due to narrow sowing windows, which harms both soil health and air quality. While alternatives exist, their impact under different rice establishment methods is not well understood. The experiment followed a split-plot design with four rice establishment methods and three replications. The establishment methods were M1: Wet Direct Seeded Rice (WDSR), M2: Modified System of Rice Intensification (MSRI), M3: mechanical transplanting and M4: manual line transplanting in main plots and the residue management practices were S1: straw removal, S2: open burning, S3: in-situ incorporation, S4: rice straw biochar application and S5: FYM application @ 5 t ha-1 in subplots. Cv. Swarna and Improved Lalat were used in Kharif and Rabi, respectively. A fertilizer dose of 80:40:40 kg ha-1 for Kharif and 60:30:30 kg ha-1 for Rabi rice was applied based on STBFR for medium N and low P and K soils. In MSRI, 50 % of N came from FYM (0.54 % N). Biochar addition improved bulk density, infiltration rate and water holding capacity. The MSRI method was very effective in improving the pH, EC, SOC and micronutrient status of the soil. Manual line planting was effective in maintaining the macronutrient (N, P and K) status of the soil. Straw incorporation was very effective in maintaining the overall soil health, including SOC, macronutrients and micronutrients. For improving the physical and chemical status of soil, modified SRI and FYM were the best practices.