Chemical study of vermicomposted agroindustrial wastes

Purpose The disposal of solid waste is a serious environmentalproblem for humanity. Vermicomposting is usedas one of the methods for recycling of organic waste,resulting in a humified material of great agronomicpotential which promotes carbon sequestration whenapplied to the soil. The aim of this study was to evaluatethe chemical characteristics of vermicomposts from cattlemanure (CM), orange peel (OP) and filter cake (FC).Methods Three compost piles were set up, 2:1 OP CM,3:1 FC CM and CM. The piles were initially compostedfor 60 days. Thereafter, earthworms were added to thepiles to initiate the vermicomposting process.Results The pH and the organic carbon contents wereabove the minimum recommended values for organic fertilizers.The N content was below the minimum value butthe C/N ratio was in the required range. The C/N valueswhere lower in OP CM and FC CM than in CM.Further, the N contents of treatments were different withOP CM having the highest value. The C/N ratios of thepiles were 9.52, 9.62 and 11.03 for OP CM, FC CMand CM, respectively, and were lower than the maximumrecommended value by the Ministry of Agriculture, Livestockand Food (Ministry of Agriculture 2009).Conclusion Thus, co-vermicomposting of filter cake andorange peel with cattle manure has the potential forapplication sustainable agriculture.