Anaerobic digestion is an optimal way to treat organic waste matter, resulting in biogas and residue. Utilization of the residue as a crop fertilizer should enhance crop yield and soil fertility, promoting closure of the global energy and nutrient cycles. Consequently, the requirement for production of inorganic fertilizers will decrease, in turn saving significant amounts of energy, reducing greenhouse gas emissions to the atmosphere, and indirectly leading to global economic benefits. However, application of this residue to agricultural land requires careful monitoring to detect amendments in soil quality at the early stages.
