Soil organic carbon stock of different land uses of Mizoram, Northeast India

Abstract

The study was conducted to assess soil organic carbon (SOC) concentration and stock under eight major land uses: shifting cultivation, wet rice cultivation, homegardens, forest (natural), grassland, bamboo plantation, oil palm plantation and teak plantation of Mizoram, Northeast India. Soil samples at different depths (0–15, 15–30 and 30–45 cm) were collected from each of the land uses under study to estimate SOC content in the laboratory. Forest recorded the highest mean SOC concentration with 2.74% at 0–45cm depth and lowest in the bamboo plantation (1.09%). Mean SOC stock for 0–45 cm soil depth ranged from 27.68 to 52.74 Mg C ha−1 in grassland and forest respectively. Both SOC concentration and SOC stock decreased with increasing soil depth. Soil bulk density of fine soil (<2 mm) was significantly negatively correlated with SOC concentration and positive with SOC stock. SOC stock loss estimated following its conversion from forest was maximum with shifting cultivation (−5.74 Mg C ha−1 yr−1) followed by oil palm plantation (−2.29 Mg C ha−1 yr−1), bamboo plantation (−1.56 Mg C ha−1 yr−1) and the least in homegardens (−0.14 Mg C ha−1 yr−1). The study results indicate the importance of SOC stocks in different land uses which may help devise appropriate management practices to increase the soil carbon sequestration potential in the wake of mitigating climate change.

Keywords

• land use types| bulk density| SOC stock| soil carbon sequestration