Prediction of soil organic carbon increase in the transition from shifting cultivation to agroforestry in the Indian East Himalayas

Abstract

Agroforestry practices managed by indigenous communities have been identified as viable alternatives to monoculture practices in the transition from shifting cultivation to sedentary agricultural systems. Nonetheless, the long‐term effects of such transitions on the dynamics of soil organic carbon (SOC) are not fully understood. In this study, we predict changes in SOC stock across a chronosequence of a natural forest stand and pineapple agroforestry systems (PAFSs) using an ensemble of models with four shared socioeconomic pathway scenarios. There was a strong agreement between the simulated and observed SOC stocks. Simulated SOC stocks with the Rothamsted Carbon (RothC) model in 15‐year‐old PAFS (83.2 Mg C ha ⁻¹ ) did not significantly differ from the value (90.4 Mg C ha ⁻¹ ) simulated for the natural forest. Simulations further revealed that average SOC stocks in 15‐year‐old PAFS would increase by 1.6 Mg C ha ⁻¹ , while SOC stocks would decrease by 5.4 Mg C ha ⁻¹ in natural forests under climate change scenarios by 2060. It is concluded that traditional agroforestry practices such as PAFS can restore degraded land under shifting cultivation in the mountainous regions of the Indian East Himalayas and contribute to achieving carbon neutrality.