Environmental impact of meat meal fertilizer vs. chemical fertilizer

► Meat meal as fertilizer uses more primary energy than chemical fertilizer. ► Meat meal as fertilizer emits less greenhouse gases than chemical fertilizer. ► Meat meal as fertilizer has a lower acidifying potential than chemical fertilizer. ► Meat meal as fertilizer has a higher acidifying potential than chemical fertilizer. ► Environmental impact from using meat meal as fertilizer depends on fuels replaced. Animal by-products (ABP) are rich in nutrients and energy. This LCA study assessed and compared the environmental impact of using meat meal as fertilizer with that of using chemical fertilizer. In one system the nutrient content of ABP Category 2 was recovered and used as a meat meal fertilizer on arable land, replacing chemical fertilizers. In the other system a chemical fertilizer was used and the energy content of the ABP material recovered. The functional unit consisted of one kg of harvested spring wheat and treatment of 0.59 kg of ABP Category 2. The system for nutrient recovery and chemical fertilizer replacement had lower emissions of greenhouse gases and acidification than the energy recovery system, but had higher total use of energy and eutrophying emissions. Overall, the results of the study greatly depended on the fuels replaced.