abstract |
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. |