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Biogas generation; Cattle manure; Renewable energy; Rural sustainability; Waste management; Anaerobic digestion; Livestock farming; Green energy; Organic fertilizer; Environmental impact

Introduction

Livestock farming, while essential for food security and rural livelihoods, generates large volumes of organic waste, particularly cattle manure, which poses significant environmental and health risks if not managed properly. In many rural areas, unmanaged manure contributes to soil and water pollution, greenhouse gas emissions, and the spread of zoonotic pathogens [1-5]. However, through anaerobic digestion, cattle manure can be transformed into biogas, a renewable energy source, and nutrient-rich digestate that can be used as organic fertilizer. This process not only addresses waste disposal challenges but also reduces dependence on firewood and fossil fuels, contributing to energy self-sufficiency in rural communities. This study explores the feasibility and sustainability of small-scale biogas systems using cattle manure as feedstock, with a focus on energy output, environmental benefits, and community adoption in rural settings [6-10].

Discussion

Field data were collected from six rural households in India and Kenya that adopted fixed-dome biogas digesters fueled primarily by cattle manure. The average herd size per household ranged from 5 to 12 cattle. Manure was collected daily and mixed with water in a 1:1 ratio before feeding into the digester. Over a 30-day retention time, methane-rich biogas was produced through microbial breakdown of organic matter in oxygen-free conditions.

On average, a daily input of 25–30 kg of fresh manure yielded 1.2–1.8 cubic meters of biogas, which was sufficient to meet the cooking fuel needs of a family of 5–6 members for a day. The energy output replaced approximately 2 kg of firewood or 1.5 liters of LPG daily, reducing both indoor air pollution and energy expenditure. Households reported substantial savings on fuel costs and less time spent on firewood collection, especially by women and children.

The digestate, a byproduct of the digestion process, was analyzed and found rich in nitrogen, phosphorus, and potassium (NPK), making it an effective organic fertilizer. Farmers reported improved crop yields when digestate was applied to their fields, reducing their reliance on chemical fertilizers.

From an environmental perspective, biogas units helped cut methane emissions from open manure pits and carbon dioxide emissions from burning firewood. The estimated reduction in greenhouse gas emissions was approximately 3.5–4 tons of COâ‚‚ equivalent per household annually.

Barriers to adoption included the initial capital cost of digester construction, lack of technical knowledge, and maintenance challenges. However, support from NGOs and local government subsidies significantly increased uptake. Training in digester maintenance and manure management was provided as part of the community engagement process. In cases where cooperative models were introduced, multiple households shared a centralized digester, which increased efficiency and minimized cost per user.

The long-term success of biogas systems in these communities was linked to regular manure availability, proper digester feeding practices, and community ownership. Integration with other farm activities, such as vermicomposting and kitchen gardens, enhanced the overall benefits of the system.

Conclusion

Biogas production from cattle manure represents a sustainable, low-cost solution for rural livestock waste management. It transforms a pollution hazard into clean energy and valuable fertilizer, addressing multiple rural development goals—sanitation, energy security, income savings, and agricultural productivity. The study highlights that with appropriate training, financing, and institutional support, rural communities can successfully adopt and maintain biogas systems. Scaling up such initiatives can reduce environmental degradation, empower rural households, and contribute to national renewable energy targets. As the world shifts toward circular bioeconomies, small-scale biogas systems offer a practical, decentralized approach to achieving sustainability in livestock-dominated rural landscapes.

References

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