Effect of the activity of black soldier fly larvae on the quality of compost produced from different organic waste sources at Makerere University Agricultural Research Institute
Abstract
With increased waste accumulation in urban areas as population increases exponentially, over 90% of the waste is attributed to organic origins. Organic wastes can be utilized to address the declining soil fertility for sustainable production if properly decomposed. Potential of black soldier fly larvae rearing in decomposition of organic wastes for manure production provides an entry point for utilization of organic wastes. This potential was evaluated through a complete random design with three replicates and three rates of the Black Soldier Fly Larvae (BSFL). The study aimed at establishing the nutrient of BSFL-composted manures for production and fertility and solving the organic waste accumulation in our urban areas using locally available means. Organic sources assessed were market waste, cow dung and poultry litter. After composting, the manure samples were thoroughly mixed; samples were dried, ground and sieved for various analyses following standard laboratory analytical procedures. Data was analyzed using a one-way analysis of variance (ANOVA) using Genstat14 edition and the selected macro and micro nutrient content generally differed significantly (p<0.05) as the trend in Nitrogen, Organic matter, Calcium and potassium followed the trend of Market waste<Poultry litter<Dung. The pH followed a trend of Dung<poultry litter<Market waste; total phosphorus followed the trend Poultry litter<Dung<Market waste. Market waste had reduced by 71.52%, cow dung by 46. 82% and poultry litter had reduced by 22.23% during the composting period. The rationale of the study was to evaluate the potential of BSFL to compost different materials. The high nutrient composition in market waste makes it the best soil amendment if we are targeting supply of K, Ca, N and O.M with the aim of improving nutrient availability in the highly weathered soils of Uganda. For soils characterized with low pH, I would recommend using BSFL composted manure from cow dung because it will raise the pH making it suitable for crop production which in turn increases crop yields. Furthermore, nutrients such phosphorus deficiency can be addressed by applying BSFL composted manure comprising of poultry litter. Finally, we can incorporate BSFL in the efforts to manage organic waste at the source especially in the urban areas.