Abstract: The invention relates to a method and a system for producing biofertilizers, from sludge that are stabilized, dried, and rich in fertilizing matters originating from high load effluent treatment method. Such solution may be integrated into an already existing treatment facility for industrial, municipal, or agronomical organic effluents (100), and is based on recovering the thermal energy created during the treatment steps of such system in bioreactors (120), air suppression units (122), biodrying units (500), drying units (600), and other units. Such recovery of energy creates a synergy that allows the increase of efficacy and yield of bioreactors (120) due to a greater stability from the temperature regulation, thus ensuring an important energy saving for the final drying step in producing biofertilizers.