Coated granular fertilizer capable of controlling the effect of temperature upon dissolution-out rate

摘要

Fertilizers coated with coating layer having a controlled moisture permeability and a controlled temperature dependency of moisture permeability are presented by the production method which comprises ejecting hot drying air to the spout of granular fertilizer and spraying a hot solution of polyolefin type resin, ethylene-vinyl acetate copolymer or vinylidene type resin upon said fertilizer granules and drying said fertilizer granules upon being sprayed with solution having the property capable of forming a solution while it is hot but turning into jelly-like gel when it is cooled but as a most characteristic feature of this method uniformly dispersed fine powder is incorporated in said drying air or in said solution so as to have a coated layer of said resin containing uniformly distributed fine powder.