Scope of horticultural land-use system in enhancing carbon sequestration in ferruginous soils of the semi-arid tropics

Soil exhaustion is a major concern particularly in ferruginous soils of the tropics and restoration of soil quality through management of soil organic carbon (SOC) is one of the options to combat the situation. To understand the scope of different systems to sequester organic carbon in ferruginous soils (Typic Rhodustalfs), three representative systems, viz. agriculture (40 years), horticulture (20 years) and forestry (several centuries) were selected in a contiguous area under semi-arid tropical climate. The study indicated that the quasi-equilibrium value (QEV) of SOC decreased from 1.78 to 0.68% in the first 30 cm, when the soils are used for agriculture instead of retaining them as forest. A shift from agricultural to horticultural system over 20 years increased the QEV to 0.81% indicating accumulation of SOC. The highest threshold value of SOC is observed in forest system, followed by horticultural and the lowest in agricultural system. The present study indicates that horticultural system is a better option to enhance the SOC if forestry is not feasible in these ferruginous soils.