Carbon sequestration potential of agroforestry systems in Indian agricultural landscape: A Meta-Analysis

Agroforestry (AF) systems offer numerous ecosystem services and environmental benefits to humanity. Compared to conventional agricultural practices, these systems have the potential to address the impacts of climate change through carbon (C) sequestration. We examined the impacts of four dominant AF systems, viz., agrisilviculture, silvipasture, agrihortisilviculture, and agrihorticulture, on soil C sequestration and the influencing factors as well as associated benefits. Results revealed that conversion to agroforestry systems resulted in a considerably higher C sequestration (+25.34%) compared to non-agroforestry systems. The highest mean soil C stock was found in agrihorticulture (38.11 Mg C ha-1), which is + 31.64% higher in comparison with conventional systems. The transformation from grasslands to agroforestry systems resulted in the highest carbon sequestration, with an increase of + 36.94%. In contrast, the transition from forest to agroforestry systems resulted in a decline in soil C sequestration (-23.42%), implying its sequestration potential outside the forest rather than the substitute of forests. AF in semi-arid subtropical regions showed higher sequestration potential compared to other regions. Further, higher C sequestration was observed in younger trees (+39.51%) and in the upper soil layers (upto30cm) of AF systems. Factors such as previous land use, system type, age, and rainfall were the major drivers of soil C sequestration in AF systems. Our findings also indicated that all the AF systems considered are technically feasible and economically profitable in the Indian agricultural landscape. Reorienting and extending incentives for agroforestry, improving certification standards for agroforestry products, and strengthening the AF extension system will be crucial in enhancing ecosystem services and supporting India's efforts toward achieving its net zero emission target.