Tillage and Manure Induced Changes in Carbon Storage and Carbon Management Index in Soybean–Wheat Cropping System in the Vertisols of Central India

Conservation tillage as part of conservation agriculture is regarded as a potential mitigation strategy to enhance the sink for atmospheric carbon in agriculture. Though, conservation tillage has been tested for its efficacy in other parts of the globe, very few information exists with regard to its C sink potential in Indian context, particularly for Vertisols of central India. Therefore, the present study was undertaken in the Vertisols of Bhopal to assess the effect of conservation tillage with or without application of manure, on carbon sequestration and carbon management index in soybean–wheat cropping system. After 4 year cropping cycle, it was observed that conversion from conventional to conservation tillage with application of manure (2.0 Mg ha −1 FYM-C) every year showed the highest impact on soil carbon sequestration and carbon management index. Under a particular manure treatment, carbon storage was higher under no-tillage in the 0–5 cm soil depth, whereas it was higher under reduced tillage in the 5–15 cm soil layer.