NOVELTY - Process for the recycling of nutrient elements and for the preparation of fertilizers, comprises: (a) anaerobic fermentation in a digester for producing a digested product and biogas; (b) placing in contact in an evaporator a flow of digested product with a recycling gas for extracting ammonia; (c) recycling of the hot digested product to the digester after mixing in a mixer with organic substrates; (d) absorption of the ammonia with a fluid for producing ammonia sulfate/phosphate; and (e) utilization of the biogas in internal combustion engines to produce e.g. electrical energy.    USE - The process is useful for the recycling of nutrient elements and for the preparation of fertilizers from organic substrates from waste coming from the cycle of production and consumption of foods using a digester, an evaporator for the extraction of the ammonia, an absorber of the ammonia and a mixer (claimed). No biological data given.    ADVANTAGE - The process is capable of efficiently producing two fertilizers (i.e. a mixed organic fertilizer and a nitrogen fertilizer) by using the waste coming from the cycle of the production and consumption of foods (organic substrates) in an industrial manner. The process allows the recycling of the nutrient elements removed from agricultural land by harvest on a regional basis, thus solving the health, environmental and logistical problems in an economical manner. The produced fertilizers have high storage stability.    DETAILED DESCRIPTION - Process for the recycling of nutrient elements and for the preparation of fertilizers from organic substrates from waste coming from the cycle of production and consumption of foods using a digester, an evaporator for the extraction of the ammonia, an absorber of ammonia and a mixer, comprises: (a) anaerobic fermentation as a continuous process in the digester at a temperature of 55 degrees C for the production of a digested product (fertilizer 1) and biogas; (b) placing in contact in the evaporator a flow of digested product exiting from the digester with a recycling gas for the extraction of ammonia, supplying the heat necessary for the evaporation; (c) recycling the hot digested product exiting from the evaporator to the digester after mixing in the mixer with the organic substrates fed with the aim of improving the homogenization in the digester and maintaining the temperature of it; (d) absorption of the ammonia with a fluid containing sulfuric/phosphoric acid for the production of ammonia sulfate/phosphate for the production of a fertilizer 2; and (e) utilizing the biogas in internal combustion engines for the production of electrical energy and the heat necessary for the process. An INDEPENDENT CLAIM is included for use of the process in centers for the recovery of the nutrient elements removed by harvesting from agricultural land, where the waste coming from the cycle of production and consumption of foods is collected during the year for the production of a first fertilizer containing stable organic substance, usable before sowing, and a second inorganic ammonium fertilizer usable also after sowing.