Slow-release compound fertilizer and preparation method thereof

Abstract

The invention provides a slow-release compound fertilizer. The slow-release compound fertilizer comprises a basic compound fertilizer, chitosan, mineral oil, nano cellulose and a water-retaining agent, wherein the basic compound fertilizer serves as a core and is sequentially coated with a first film layer and a second film layer, the first film layer comprises chitosan and mineral oil, and the second film layer comprises nanocellulose and a water-retaining agent; the slow release effect is achieved, the moisture stability in the soil is maintained and improved, sufficient nutrients in the soil are maintained, the absorption of the plants to the basic compound fertilizer is efficiently promoted, and the growth and development of the plants are promoted; and the release speed of nutrient substances in the soil is reduced, the utilization efficiency of the fertilizer is improved, and the pollution to the surrounding environment is effectively avoided. The preparation method comprises the following steps: firstly, preparing a first film layer coating liquid from chitosan and mineral oil, coating the surface of fertilizer particles with the first film layer coating liquid, and then coating the outer surface with a second film layer coating liquid formed by nano cellulose and a water-retaining agent, thereby preparing the double-layer coated slow-release fertilizer particles.

Description

technical field [0001] The invention relates to the technical field of fertilizers, in particular to a slow-release compound fertilizer and a preparation method thereof. Background technique [0002] Fertilizers are the material guarantee for the sustainable development of agriculture and the basis of agricultural production. Crops often require a variety of nutrients during their growth and development, so fertilizer nutrients play a vital role in plant growth. At present, my country's fertilizer nutrient utilization rate is not high, and a large part of the nutrient elements will enter the external environment from the farmland system, which not only causes fertilizer waste, but also brings farmland pollution. [0003] In the prior art, slow-release compound fertilizers, such as organic polymer-coated slow-release fertilizers, sulfur-coated urea, and urea-formaldehyde slow-release fertilizers, are prepared to solve the problems of excessively fast release of fertilizer nu...

AI Technical Summary

Problems solved by technology

[0006] The Chinese patent with the application number CN201510170410.5 discloses a water-retaining slow-release compound fertilizer and its preparation method. It consists of 60-75 parts of chemical fertilizer, 1-6 parts of water-retaining agent and 19-39 parts of filler. It is made by directly mixing chemical fertilizers, water retaining agents and fillers and granulating them. In this way, on the one hand, water retaining agents and fillers are mixed in fertilizer granules, which slow down the fertilizer nutrients. The release effect is limited; on the other hand, the water-retaining agent will absorb water and swell during the granulation process, which seriously affects the granulation rate and granule strength.

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