Manure Management and Biogas Production in Livestock Farms in South West Nigeria

This study examines manure management practices and evaluates biogas production opportunities in livestock farms in South West Nigeria, assessing both the environmental impacts of current practices and the economic potential of anaerobic digestion systems. Livestock manure mismanagement creates significant environmental pollution risks in South West Nigeria's densely populated agricultural-urban interface, while simultaneously representing an underexploited energy and fertiliser resource. Commercial poultry and pig farms in Lagos, Ogun, and Oyo States generate substantial manure volumes that are mostly surface-disposed with minimal treatment. This study audits manure management systems at 30 commercial livestock farms and conducts biogas potential assessments using biochemical methane potential tests on manure samples from each farm type. Economic modelling estimates the viability of farm-scale biogas systems of varying designs. Regulatory compliance with environmental standards is assessed. Findings reveal that 78 percent of sampled farms dispose of manure through surface land application without composting or treatment, with 22 percent relying on open burning. Methane potential of poultry manure averages 0.34 cubic metres per kilogram volatile solids, significantly higher than swine manure at 0.27. Farm-scale biogas plants with 50 to 100 cubic metre digester volume show payback periods of 3.2 to 5.8 years depending on farm scale and electricity cost savings. Environmental regulation enforcement on livestock farms is minimal. The study recommends a South West Nigeria livestock manure management programme combining environmental compliance incentives with subsidised biogas installation support.

Keywords: manure management, biogas production, livestock farms, South West Nigeria, environmental pollution.