Studying the relationship between total organic carbon and soil carbon pools under different land management systems of Garo hills, Meghalaya

Abstract

The contribution of land uses in sequestering soil carbon (C) is a key question of research in tropical regions, where C emissions due to land use changes, extreme rainfall events and high temperatures can aggravate the global issue of climate change. In the present study, different pools of soil organic C were assessed, from shifting cultivation lands (jhum), rubber, tea garden and coffee plantations of Tura district in Meghalaya, which is located in Northeastern region (NER) of India. To achieve this goal, different parameters such as bulk density (BD), total organic carbon (TOC) and C pools, viz., very labile (C_VL), labile (C_L), less labile (C_LL) and non-labile (C_NL) were analyzed. The results indicated significant correlations among TOC and C pools in most land uses, except for C_NL pool. Tea gardens showed the highest value of TOC stock (62.75 ± 1.47 t C ha^-1) while the lowest was found in the jhum lands (33.34 ± 5.04 t C ha^-1). Similarly, both the active (12.03 mg g^-1) and passive (4.60 mg g^-1) C pools were highest under tea gardens. C_VL was found to be positively correlated with TOC and active carbon pool (ACP), while C_LL was also positively correlated with passive carbon pool (PCP). This study indicates the potential of tea gardens as a promising C sequestering land use, which can be promoted in jhum lands to mitigate the negative impacts of climate change.

Keywords: Entisols; Northeast himalaya; Shifting cultivation; Soil carbon pools; Tea garden.