Sustainable Soil Management for Climate Resilience: Long-Term Management Effects on Soil Carbon Sequestration and Nitrogen Dynamics in a Semi-Arid Tropical Inceptisol of India

The injudicious use of synthetic agri-inputs has adversely influenced the soil fertility in tropical and subtropical agriculture with depleted reserves of carbon (C) and nitrogen (N) Assessing dynamics of these nutrient elements and their impacts on crop productivity in irrigated semi-arid cropping systems are immensely influenced by the climate induced crop nutrient responses. Therefore, to comprehend the fundamental mechanisms that govern the carbon and nitrogen dynamics in diverse nutrient management systems is crucial for understanding the effects of climate-induced variations in nutrient availability on crop yield. In this study, surface soil (0-15 cm) samples were collected from four different sources: 100% organic sources (T-1), 75% organic + 25% inorganic sources (T-2), 50% organic + 50% inorganic sources (T-3), and 100% inorganic sources (T-4). The samples were then subjected to analysis for C and N dynamics, along with C sequestration potential. The data was collected from the following cropping systems; rice-wheat-sesbania (CS1) and rice-barley-green gram (CS2). The soil potential for C sequestration exhibited a range of 0.18 to 0.02 Mg C ha(- 1) yr(- 1) in CS1 and 0.17 to 0.03 Mg C ha(- 1) yr(- 1) in CS2, respectively, across the soil nutrient treatments. The long-term addition of organic sources in organic ameliorations with or without inorganic fertilizers significantly enhanced active carbon and nitrogen pools compared to 100% inorganic nutrient treatment in both the cropping systems. The ammoniacal and nitrate nitrogen extracted from inorganic nutrient treated soils were higher than that of organic treatments. Subsequently, soils amended with organics had superior biological quality in terms of higher MBC, PmOC and MBN than other treatments. The higher sustainability yield index (similar to 0.79) was recorded in organically amended soil among the cropping systems. The research findings demonstrate that the continuous incorporation of organic amendments for long-term is a beneficial approach for improving the dynamics of soil carbon and nitrogen in tropical soils.