Method for producing fertilizer, fertilizer

A low water content, low chlorine, low potassium fertilizer is provided. A method for producing a fertilizer that is hygienic and safe and can be produced at low cost. Water is added to livestock excrement and mixed to form an organic waste slurry (S1). The slurry is put into the dehydrator 11 and dehydrated until a predetermined moisture content is obtained. The desalted organic waste is put into a drier, heated to at least 60 ° C. with hot air or the like, and dried (S3). The desalted organic waste has a water content of 5% by mass or more and 20% by mass or less. For example, exhaust heat generated in a cement kiln in a cement manufacturing process (factory) may be used as exhaust heat serving as a heat source for the dryer. [Selection] Figure 1