Soil Organic Carbon Storage in Different Landforms of South Deccan Plateau of Andhra Pradesh

Thirty-two soil profiles and 44 sutface soil-sites in the cultivated areas representing five landforms in South Deccan Plateau of Andhra Pradesh were studied for estimating the soil organic carbon (SOC) storage in soils. The study revealed that SOC content in the sutface 0.15 m and up to one m depth varied in different landforms. The content of mean organic carbon in the sutface 0.15 m soils was highest in alluvial landform whereas basalt landform showed the highest in the upper one m depth. Granite-gneiss and sandstone landforms showed the least organic carbon storage in both the upper 0.15 m andup to one m soil depth. The mean SOC storage in the five landforms is in the order of basalt> alluvial> laterite> sandstone> granitegneiss. Parent materials were found to influence the organic carbon storage through its control on soil texture. Drainage played a pivotal role in the distribution and amount of organic carbon especially in granite-gneiss and sandstone landforms. Grouping of soils on the basis of the different soil orders revealed that Vertisols have the highest organic carbon, whereas it was least in Entisols. The ranking of SOC storage in different soil orders was in the order: Vertisols> Inceptisols > Alfisols> Entisols.