A plant (10) for treating poultry manure comprises:—an apparatus for the first treatment (11) of the poultry manure, configured to carry out dilution, homogenization and hot, damp alkaline hydrolysis of the diluted poultry manure and to supply at exit a stream of inert materials (18) and a stream of hydrolyzed poultry manure (19) —a second treatment unit (20) configured to carry out a flocculation of the stream of hydrolyzed poultry manure (19) and to supply a hydrolyzed and flocculated stream of poultry manure (22)—a solid-liquid separation unit (24) configured to separate the stream of hydrolyzed and flocculated poultry manure (22) into a solid fraction (26) suitable for anaerobic digestion and a liquid fraction (28)—a liquid post-treatment unit (30) of the liquid fraction (28) supplied by the solid-liquid separation unit (24) configured to recover water (32, 60), ammonium sulfate (31, 56) and salts (34, 54, 54a) from the liquid fraction (28).
