The circular economy concept application to livestock systems: an agroecological approach

Over the last century, livestock systems have undergone a progressive intensification process, which brought to light many environmental and agronomical issues, mainly related to manure management. An agroecological approach has also been advocated to develop more sustainable systems and ensure a balanced relationship between environmental, social and economic goals. The circular economy (CE) concept was placed next to that of agroecology, and its application to manure management was finalized to reduce the input and use of natural resources, increase sharing of energy and natural resources and reduce pollution. This review comprehensively reports the more interesting opportunities for European Cattle breeding, considering that its waste management plays an important role from the agroecological point of view. Many technologies based on biological and/or thermochemical processes are currently available and different studies on how to improve their efficiency are under way. The biorefinery concept concerns the lignocellulosic fraction exploitation for biofuels, by-products and biochar/hydrochar production. The enhancement of farm nutrient utilization could restore the balance between input and output. The knowledge of the fertilizing/amendment properties of the manure and its by-products could create a synergistic development at landscape scale considering other agricultural production (crops, orchards, vineyards, etc.). Some ecological services such as soil fertility, biological regulations, soil erosion and biological diversity provided by animal farming could be a product of the transition towards circular economy. By adopting an agroecological approach, the enhancement of the energetic, agronomic and biochemical exploitation of manure will be sustainable