Background While the benefits of modern fertilisers are well known, their manufacture has a huge impact on the environment. The fertiliser industry alone accounts for 1.2% of the world’s total energy consumption. Ammonium is the basic component for the production of nitrogen fertilisers, but this process is very energy intensive (36.6 GJ/t NH3) as well as producing high emissions of CO2 (1966.8 kg CO2 eq/kg) and nitrogen oxides. Organic fertilisers obtained from animal waste, however, can partially substitute inorganic fertilisers, but there are some difficulties linked to their variable composition, dosage and application which limit their applicability and give rise to soil, air and water pollution. This problem is enhanced by the intensification in the world production of livestock that has led to the increase in the amount of manure production in the EU to 1 500 million tonnes/year. Objectives The objective of the ‘LIFE MIX_FERTILIZER’ project is to demonstrate an innovative system for the agronomic valorisation of waste from the anaerobic digestion (decomposition without oxygen consumption) of pig manure (digestate) and to improve the associated environmental impacts. As a result of the project actions, a new type of fertiliser will be obtained with a mixed organic/mineral base and with gradual release by the addition of the nitrification inhibitor 3-4 dimethylpyrazole phosphate (DPPP). An aqueous effluent will also be obtained and employed in fertigation. Specific objectives include: Coordinated management of the demonstration plant and optimal integration of the individual steps for treating 120 m3 of digestate per day; Stabilisation of the digestate solid phase by composting; Recovery of the inorganic nitrogen from the liquid phase by stripping for its further use in the new fertilisers replacing the synthetic mineral content; Gradual release of fertilisers will reduce the nitrogen losses by leaching or GHG emissions such as nitrogen oxides; Validation of the advantages of the new fertilisers through their evaluation in field trials with wheat crops, rain fed and irrigated, in two controlled trials covering a total of around 0.7 ha, including control plots; Use of the water obtained as a by-product in the stripping process for the fertigation of sunflower, rain fed and irrigated. Two controlled trials will be conducted on a total of 0.7 ha; Promote compliance with EU legislation in the field of waste management of pig manure, especially regarding nitrates (91/676/EEC); Reduction of the carbon footprint associated with agricultural activities; Increase of awareness of the stakeholders and farmers on environmental pollution associated with their activities and the advantages of the new fertilisers. Expected results: Treatment of 100% of the pig manure digestate and its agronomic valorisation as novel fertilisers, combining environmentally friendly solutions; Pollution reduction from nitrate leaching in at least 20% by proper design and implementation of the gradual-release fertilisers obtained in the project; Reduction in emissions of nitrous oxide (N2O) by 45-50% in the wheat plots where novel fertilisers will be used compared to control plots with conventional products; Reduction in mineral fertiliser consumption by 30% and a dynamic internal market for fertilisers; A reduction of agricultural cost through the use of new fertilisers, as a single application before planting will be possible, leading to similar yields to those with conventional fertilisation; Improvement in overall soil quality and increased agricultural yields after implementation of the new organic-mineral fertilisers in field trials (increased productivity by at least 10%); At least 20 farmers will have tested the new fertilisers, of which 60% will express their satisfaction in surveys.