Carbon Sequestration Potential and Soil Carbon Stock Under Diversified Rice-based Cropping Systems in Inceptisols of Eastern India

Abstract

A field experiment was conducted during June, 2023 to May, 2024 at the Central Research Station of Odisha University of Agriculture and Technology, Bhubaneswar, India, under irrigated medium land conditions to evaluate the carbon sequestration potential and soil carbon stock dynamics under diversified rice-based cropping systems in Inceptisols of Eastern India. The study was conducted during the seventh crop cycle of an ongoing field experiment comprising twelve rice-based cropping systems in a randomized block design with three replications. The results showed that diversified rice-based cropping systems significantly improved soil organic carbon, carbon stock and bulk density. The lowest bulk density (1.31 Mg m^-3) and the highest soil organic carbon (8.0 g kg^-1) were recorded under the GM-rice-greengram-cowpea (vegetable) system, followed by GM-rice–cowpea (vegetable)-greengram (7.9 g kg^-1). Soil carbon stock increased at all soil depths (0–15, 15–30 and 30–45 cm), with the highest values (15.65, 8.06 and 5.64 Mg C ha^-1, respectively) recorded under the GM-rice–greengram–cowpea (vegetable) system. This system also recorded the highest carbon sequestration potential (0.51 Mg C ha^-1 yr^-1), followed by GM-rice–cowpea (vegetable)–greengram (0.43 Mg C ha^-1 yr^-1). The findings indicate that rice-based cropping systems incorporating green manure and legumes enhance soil carbon storage and sequestration, contributing to sustainable soil management and climate change mitigation.