Preparation method of coated controlled-release compound fertilizer

Abstract

The invention relates to a preparation method of a coated controlled-release compound fertilizer, which comprises preparation of a coating solution and coating of compound fertilizer granules. The preparation method comprises the following steps: in combination with common granulation equipment, under specific process conditions, synthesizing a fertilizer coating layer by taking degradable high molecular soil conditioner polyvinyl alcohol, natural high molecular starch and fertilizer sustained release agent as main components; and coating a granular compound fertilizer, thus preparing the coated controlled-release fertilizer integrating the functions of simultaneously realizing controlled release of nitrogen, phosphorus and potassium nutrients, having a degradable coating layer, improving soil and the like. The fertilizer efficiency duration is up to 60-100 days; the single-dose application of the fertilizer can satisfy the requirements of crops for nutrients during the whole growing season; and the loss of the fertilizer is effectively decreased, and the utilization ratio of the fertilizer is increased. The coating layer can be biologically degraded within 100 days; and the degraded components are harmless and non-toxic, and effectively improve the soil structure. Besides, the compound fertilizer is accessible in raw materials, simple in processing technique, low in cost and convenient to produce and use.

Description

technical field [0001] The invention relates to a preparation method of coated fertilizer. Background technique [0002] Chemical fertilizers used in agricultural production are prone to leaching, chemical fixation, and volatilization reactions in the soil, resulting in serious loss of fertilizer nutrients, low utilization rate, and serious environmental pollution, soil caking and other consequences. [0003] In order to improve the utilization rate of fertilizers, our technicians develop and produce coated fertilizers. However, at present, coated fertilizers with a fertilizer effect period of more than 70 days have disadvantages such as a small amount of fertilizer in the early stage, which cannot meet the needs of crop growth, difficult fertilization technology, difficult to control, and difficult to degrade the film material. Contents of the invention [0004] The object of the present invention is to provide a coated controlled-release compound fertilizer which has si...

AI Technical Summary

Problems solved by technology

However, at present, coated fertilizers with a fertilizer effect period of more than 70 days have disadvantages such as low fertilizer supply in the early stage, which cannot meet the growth needs of crops, difficult fertilization technology, difficult to control, and difficult to degrade the film material.