Response to Letter to the Editor "Comments on "Modelling soil organic carbon storage with RothC in irrigated Vertisols under cotton cropping systems in the sub-tropics" (Nimai Senapati, Nilantha R. Hulugalle, Pete Smith, Brian R. Wilson, Jagadeesh B. Yeluripati, Heiko Daniel, Subhadip Ghosh, Peter Lockwood. Soil & Tillage Research 143 (2014) 38-49)