The chemical characteristics of composted and vermicomposted cotton residues case study in Sudan

Purpose - The purpose of this paper is to investigate the influence of two decomposition processes, namely, composting and vermicomposting, on the chemical composition of the finished products of a mixture of: cotton residues; soil and cotton residues; farmyard; soil. Design/methodology/approach - Composting experiments were done over six months to prepare four different mixtures as follows: cotton residues+soil (C); cotton residues+soil+earthworms (C+E); cotton residues+soil+farmyard manure (C+F); and cotton residues+soil+farmyard manure+earthworms (C+F+E). Electrical conductivity, pH, nitrate-N, ammonium-N, ash, total phosphorus, total nitrogen, total organic carbon, carbon: nitrogen ratio, total potassium and trace elements (Mn, Fe, Cu and Zn) were determined on monthly-based samples. Findings - Significant differences (p