Carbon, Nitrogen and Sulphur Mineralisation in a Soil from Three Decomposing Plant Materials of Varying C/N, C /S and N/S Ratios

Department of Agricultural Chemistry and Soil Science, Bidhan Chandra Krishi Vlswa Vidyalaya, Kalyani, West Bengal Manuscript received 17 December 1980, revised 17 August 1981, accepted 10 December 1981 A laboratory incubation study was undertaken to compare the carbon, nitrogen and sulphur mineralisation in a soil from three decomposing plant materials, namely, dhaincha (\(Sesbania\) \(aculeata\)), cowpea (\(Vigna\) \(sinenns\)) and waler-hyacinth (\(Eichorna\) \(crasspipes\)) of varying C/N, C/S and N/S ratios applied at five different levels. Both carbon and nitrogen mineralisation from three different plant materials followed the order : dhaincha≥cowpea≥water-hyaeinth. The extent of carbon mineralisation was found to be a reflection of the organic carbon content of tbe added organic matter. C/N ratio of the added plant material predominantly controls nitrogen mineralisation in soil. While sulphur mineralisation was found not only to depend on the sulphur content of the added plant material but also to their composition in relation to organic carbon and total nitrogen