Enhancing organic waste decomposition with addition of phosphorus and calcium through different sources

Purpose This study assessed the constituent element in rock phosphate (RP) that is responsible for enhancing quick decompositionof cow dung–waste paper mixtures during vermicomposting.Method Feedstock weighing 5 kg was achieved by mixing 2.16 kg shredded waste paper together with 2.84 kg cow dungsprinkled with water and then enriched with (1% P) as RP from triple superphosphate (TSP), phosphoric acid (PHA) andCa in the form of CaCl2at the level supplied by RP. After mixing, they were loaded into vermireactors and inoculated withmatured earthworms at a stocking density of 12.5 g worms/kg feed for the entire 56 days. The decomposition of the mixtureswas then monitored by measuring maturity parameters, a germination test for phyto-toxicity and morphological propertieswas assessed using scanning electron microscopy (SEM).Result Results revealed that rapid decomposition of waste was recorded where TSP was applied than RP whereas Ca-sourcehad the least effect. A C:N ratio of 12 was achieved within 28 days where TSP was added, while RP, PHA and CaCl2needed42, 56 and more than 56 days, respectively.Conclusion It was evidently revealed from the results that P was basically the cause of the improved decomposition of thewaste mixtures. To achieve quicker and well-humified enriched vermicompost with a C:N ratio of 10 within 20 days ofvermicomposting, add water-soluble P sources.