abstract |
Products for the variable controlled release of water soluble agents are disclosed. The products have a core of water soluble agent and a first and second coating. The first coating has a permeability such that the agent can be released at a controlled rate, while the second coating has a relatively low water vapor transmission rate. Variation in the coating thicknesses and coating conditions result in nutrient release profiles which can be tailored to specific plant requirements. After application of the product, release of the agent is negligible, but after a predetermined time, e.g. one month or more, substantial release of the agent from the coated product begins. The product is particularly suitable for delayed, controlled release fertilizers. |