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Soil organic carbon (SOC) content in Indian soils has been reported as low, which is in tune with the fact that nearly 60% of the area in India represents the typical tropical climate, which does not permit SOC accumulation. Recent evaluation with the help of more soil and site data, model approaches and long-term fertilizer experiments (LTFEs) show an increasing trend of SOC, as detailed in this chapter through different case studies in two important food growing zones of India, namely the Indo-Gangetic Plains (IGP) and the black soil region (BSR). The study shows the evaluation of Century, RothC and InfoCrop models in LTFEs with contrasting bioclimate in the IGP and the BSR. The Century model experience necessitates the modification of crop information to suit the tropical conditions found in India. The RothC output has been found to be useful to arrive at the threshold limit of the mean annual rainfall as an indicator of organic carbon storage in soil. The InfoCrop cotton model in the BSR indicated that the interaction of increased temperature and CO2 concentration had a compensatory effect on crop yield. A methane emission study on Indian agricultural soils has been computed as 2.54 Tg C-CH4 year(-1) and constitutes 0.23% of global warming. However, although an increase of SOC has been found in IGP and BSR soils, even in arid and semi-arid environments, the status of soil inorganic carbon will require attention by planners and resource managers in view of soil degradation.