An experimental study of vermi-biowaste composting for agricultural soil improvement

Vermitechnology was investigated as a means of reducing organic waste materials. Vermicomposting conditions were optimized to convert the biowastes to nutritious composts for amending agricultural soil. Studies were undertaken to select the most suitable earthworm species for vermicomposting, to enrich vermicompost by inoculation with beneficial microbes, to standardize an economically feasible method of vermicomposting, to achieve nutrient economy through vermicompost application in acid soils (pH 4.5), and to assess the performance of vermicompost as a bioinoculant in cow-pea, banana, and cassava. Earthworm species Eudrillus eugineae, Eisenia foetida, Perionyx sansibaricus, Pontoscolex corethrurus and Megascolex chinensis were compared for their efficiencies in biodegrading organic wastes. E. eugineae was found to be a superb agent. As a bioinoculant, vermicompost increased nitrogen and phosphorous availability by enhancing biological nitrogen fixation and phosphorous solubilisation. Vermicompost-amended acid-agriculture-soil significantly improved the yield, biometric character and quality of banana, cassava and cow-pea. Vermicompost application stimulated root growth, facilitating nutrient absorption and thereby favouring higher yield.