The non-commercial energy sources such as cattle dung, crop residue, forest waste and firewood contributed more than 89 per cent of energy consumed in rural households with extremely poor heat conversion efficiency of about 8-10%. This ultimately leads to atmospheric pollution during its burning and on the other side, high dependence on firewood may pave the way for deforestation. The biogas produced through anaerobic digestion of biowastes by micro-organisms offers an appropriate technique to convert non-conventional energy into conventional energy. In particular, the biogas produced is clean, combustible and pollution-free. The technology is simple and appropriate for both rural and urban areas. The utilization of biogas in a farming system may reduce the greenhouse gas, which is responsible for global warming that leads to climate change. In addition, the bio-digested slurry (BDS) can be recommended under organic agriculture. On a large scale, biogas systems may reduce the demand on fossil fuel energy resources and fertilizer cost. The paper reviews the role of biomass anaerobic digestion technology in utilization of biogas as fuel, BDS as fertilizer and other applications in organic agriculture.

Keywords:
Anaerobic digestion, Biogas, Biofertilizer, Energy, Sustainable agriculture