Pedometric mapping of soil organic carbon loss using soil erosion maps of Tripura

Importance of soil organic carbon (SOC) in maintaining soil productivity and natural ecosystem has been a major concern throughout the globe. SOC in the humid tropical climate becomes more important in view of undulating hilly terrain in the northeastern region of India. The major concern in such landscape is soil erosion and the necessary conservation practices. In the present study, we discuss the technique of pedometric mapping to link SOC and soil loss. The best-fit semi-variogram model for SOC was found to be exponential model (R2 = 0.90). The best fit semi-variogram models for soil and SOC losses are spherical (R2 = 0.95) and exponential (R2 = 0.77) respectively. The spatial distribution of SOC, soil and SOC loss was found to be related with topography and different land-use types and showed moderate spatial dependence. With the help of 196 grid observations, the present study shows a threshold limit of 150 kg ha–1 year–1 SOC loss above which the areas are to be considered as susceptible demanding immediate conservation measures. Pedometric mapping using SOC and soil loss can, thus, be a tool to prioritize areas in humid tropical climate for conservation agriculture.