Organic carbon stock in Indian soils and their geographical distribution

The first ever estimate of organic carbon (OC) stock in Indian soils was 24 .3 Pg (1 Pg = 10(15) g) based on 48 soil series taking into account of a fe w major soils. The present OC stock has been estimated as 63 Pg in the firs t 150 cm depth of soils. Soils with their geographical distribution through the country were used for computing soil organic carbon (SOC) stock in dif ferent depths in various physiographic regions. To sustain the quality and productivity of soils, the knowledge of OC in terms of its amount and quali ty in soils is essential. This has more relevance in soils of the tropical and subtropical parts of the globe, including the Indian sub-continent. SOC stock appears to be a single parameter that can help effectively in priori tizing the area for restoring soil health.