EFFECTS OF EARTHWORMS ON LIVESTOCK AND POULTRY MANURE COMPOSTING AND ITS ENVIRONMENTAL AND ECONOMIC SIGNIFICANCE: A META-ANALYSIS

Abstract

The rapid accumulation of organic solid waste, particularly livestock and poultry manure, poses significant environmental challenges. As the need for sustainable waste management grows, composting and vermicomposting have emerged as promising biological treatment methods. This meta-analysis aims to evaluate the role of earthworms in enhancing the composting of livestock and poultry manure, focusing on both the environmental and economic impacts. By examining numerous studies, the analysis highlights the effectiveness of earthworm-assisted composting (vermicomposting) in accelerating the degradation of organic waste, improving nutrient recovery, and reducing harmful emissions. While the composting and vermicomposting processes contribute to greenhouse gas emissions, the presence of earthworms, coupled with proper management practices such as intermittent aeration and the addition of bulking agents, can mitigate these emissions. The economic viability of livestock and poultry manure composting is also assessed, revealing that while the technology is generally economically feasible, its success is influenced by factors such as the market value of organic fertilizers and system-specific costs. Furthermore, the value of organic fertilizers and the availability of carbon offsets for nutrient recycling are crucial in determining the economic sustainability of these processes. This meta-analysis underscores the importance of integrating earthworms into manure composting as a strategy to improve both environmental sustainability and economic returns.