Cross-linked polyol coated release fertilizers

摘要

A controlled release fertilizer material comprising a particulate plant nutrient surrounded by a coating including a mixture of a cross-linked polyol and an isocyanate, and optionally a wax, is described. In some embodiments, the cross- linked polyol can be cross-linked with sulfur, oxygen, and/or a peroxide cross- linking moiety. In one embodiment the cross-linked polyol is castor oil cross-linked with sulfur.