Improvement of Vermicompost: Influence of Feeding Materials and Inoculation of Nitrogen-Fixing and Phosphate-Solubilising Bacteria

Abstract

Rapid urbanisation, encroachment of fertile area and booming population are leading to generation of massive amount of waste. Vermicompost has been proved as potential technology for converting different organic solid waste including municipal waste and agricultural waste into valuable wealth through a type of biological alchemy of earthworm. The egested cast can be used to improve the fertility and physical characteristics of soil. So definitely the material that ingested by the epigeic earthworm could be one of the source of variation of quality of the ultimate product. The enrichment can also be achieved by inoculating microorganisms at initial stage of decomposition. With these two aims, the present work was carried out to study the effect of different organic wastes, namely water hyacinth, cow dung, green gram, vegetable waste and poultry litter, with microbial inoculants on chemical and biochemical properties of vermicompost. Significant variation with respect to microbial count both at initial stage and final product was observed with exception like total bacterial count at initial stage and total fungal count and Pseudomonas count in final product. Inoculation of microorganisms increased the P content in vermicompost. During the incubation period, the inoculated bacterial strains proliferated rapidly, solubilised added and native phosphate. It was also observed that the percentage increase in microbial population was found maximum in water hyacinth [327.78%]. It is evident from results that the significant increase of total phosphorus and total potassium and significant decrease in TOC, EC and pH in final vermicompost of different animal/agro and kitchen wastes by the use of earthworm Eisenia foetida are due to the vermic activity.