A method for producing an organic fertilizer with humic substance properties by oxidizing and ammonifying lignite, wherein the organic fertilizer has a nitrogen content of up to 8 wt.%, based on the dry weight of the fertilizer, and a C/N ratio of 7 to 15, characterized in that the method is carried out as a continuous method and comprises the following steps: a) feeding lignite particles and aqueous ammonia solution as well as optionally recovered product of step b) as starting materials into a dispersing circuit having a dispersing device, a recirculation container, and a circulation pump, and dispersing the starting materials while simultaneously reducing the lignite particles in size until a suspension of lignite particles and aqueous ammonia solution is formed that is taken out of the dispersing circuit and transferred to step b); b) oxidizing the suspension obtained in step a) in an oxidation reactor with an oxygen-containing oxidizing agent at a temperature of <100 °C, thereby forming a product suspension that is completely transferred to step c) or partially to step c) and partially to step a) as starting material; c) drying the product suspension obtained in step b) at a temperature of >50 °C up to a residual moisture content of at most 30 wt.%, based on the total weight of the dried product; d) cooling the dried product obtained in step c). characterized in that the method is carried out as a continuous method and comprises the following steps: a) feeding lignite particles and aqueous ammonia solution as well as optionally recovered product of step b) as starting materials into a dispersing circuit having a dispersing device, a recirculation container, and a circulation pump, and dispersing the starting materials while simultaneously reducing the lignite particles in size until a suspension of lignite particles and aqueous ammonia solution is formed that is taken out of the dispersing circuit and transferred to step b); b) oxidizing the suspension obtained in step a) in an oxidation reactor with an oxygen-containing oxidizing agent at a temperature of <100 °C, thereby forming a product suspension that is completely transferred to step c) or partially to step c) and partially to step a) as starting material; c) drying the product suspension obtained in step b) at a temperature of >50 °C up to a residual moisture content of at most 30 wt.%, based on the total weight of the dried product; d) cooling the dried product obtained in step c). a) feeding lignite particles and aqueous ammonia solution as well as optionally recovered product of step b) as starting materials into a dispersing circuit having a dispersing device, a recirculation container, and a circulation pump, and dispersing the starting materials while simultaneously reducing the lignite particles in size until a suspension of lignite particles and aqueous ammonia solution is formed that is taken out of the dispersing circuit and transferred to step b); b) oxidizing the suspension obtained in step a) in an oxidation reactor with an oxygen-containing oxidizing agent at a temperature of <100 °C, thereby forming a product suspension that is completely transferred to step c) or partially to step c) and partially to step a) as starting material; c) drying the product suspension obtained in step b) at a temperature of >50 °C up to a residual moisture content of at most 30 wt.%, based on the total weight of the dried product; d) cooling the dried product obtained in step c).