Manure management in EU for biosecurity increase and livestock farming footprints reduction

The spread of livestock diseases, such as African swine fever (ASF) or the highly pathogenic avian influenza (HPAI), caused by viruses and/or bacteria such as Salmonella spp. and Escherichia coli, are currently reducing biosecurity; as such, EU regulations avoid the use of derived manure for biofertilisation. This is happening in a global context, where the price of food, fertilisers, and energy have a strong correlation. In fact, surges in the cost of these commodities contribute to strong tensions in food-insecure countries, very often resulting in food riots. This review paper addresses the current technologies available in the EU for the treatment of manure, including that derived from livestock affected by the above diseases. Additionally, within the agricultural sector, livestock farming is the major source of greenhouse gas (GHG) emissions, such as methane, nitrogen monoxide, and carbon dioxide, which contribute to global warming and, therefore, climate change. Thus, this paper also discusses manure management technologies aimed at reducing GHG emissions, considered as livestock farming footprints according to EU regulations. The literature review followed a widely implemented method divided into three phases: planning (theoretical background), execution (search strategy), and result analysis. The current technologies available in the EU for manure management are aerobic treatment, composting, anaerobic digestion (AD), decanter centrifuge, VP-HoBe, BENAS AD, Geamix housing system, belt press sieve–reverse osmosis, vibrating reverse osmosis, granulation, gasification, and pyrolysis. RENURE (REcovered Nitrogen from manure), i.e., an organic fertiliser that is partially or totally derived from manure, can replace synthetic chemical/mineral fertilisers, thereby building up a resilient food production chain capable of using locally available resources. This review indicates that pyrolysis and AD are the best suited technologies for processing manure that may be affected by the above diseases, as they have been proven to effectively avoid the spread of those specific pathogens. Moreover, these two technologies can reduce livestock footprints. However, further research will need to assess the selected manure management technologies through the computation of energy balance, in order to maximise energy efficiency.