Method of producing artificial guano

A process for producing a slow release ammonium magnesium phosphate fertilizer from animal manure comprising

• a forming a mixture of animal manure and calcined soft burned dolomite, the dolomite being added in sufficient amount to raise the temperature of the mixture to above about 100° C. upon hydration and in excess of the amount necessary to react with the phosphate values present in the manure;
• b adding water to said mixture, wherein the calcined dolomite is hydrated and the temperature of the mixture raises to above about 100° C., thereby destroying parasites and undesirable bacteria, while ammonia is released from the mixture;
• c absorbing the ammonia in an aqueous acidic medium, forming an aqueous solution of an ammonium salt:
• d adjusting the pH of the mixture obtain in step b to about between 7.0 and 7.5;
• e inoculating the mixture obtained in step d with an aqueous suspension of natural guano and anaerobically fermenting the mixture to produce said fertilizer.