Coated sustained-release agent for saline-alkali soil and preparation method thereof

Abstract

The invention discloses a coated sustained-release agent for saline-alkali soil and a preparation method thereof. The coated sustained-release agent comprises the following raw materials by weight: 60to 75 parts of ultrafine powder of mineral-derived humus, 0.1 to 0.4 part of biodegradable plastic, 1 to 5 parts of a soil moisture conservation agent, 8 to 15 parts of monoammonium phosphate, 8 to 16 parts of potassium chloride and 8 to 18 parts of urea. The coated sustained-release agent has long fertilizer effect and fixed degradation time of a coating, solves the trouble of repeated fertilization, is low in cost and capable of improving a soil environment, and has obvious improvement effect on saline-alkali soil.

Description

technical field [0001] The invention relates to a soil conditioner, in particular to a saline-alkali soil coating slow-release agent and a preparation method thereof. Background technique [0002] Inorganic fertilizers are mineral fertilizers, also called chemical fertilizers, or chemical fertilizers for short. It has the characteristics of simple ingredients, high content of active ingredients, easily soluble in water, fast decomposition, and easy absorption by roots, so it is called "quick-acting fertilizer". Common chemical fertilizers are "inorganic fertilizers". Inorganic fertilizers refer to fertilizers produced by chemical synthesis methods, including nitrogen, phosphorus, and potassium compound fertilizers. [0003] The utilization rate of chemical fertilizers in China is not high, and the utilization rate of nitrogen fertilizer in the current season is only 35%. The fertilizer effect of inorganic fertilizers is generally about two months, and there are also slow-r...

AI Technical Summary

Problems solved by technology

The solvent-based coating used in the past has insufficient solvent recovery, and the film is made of discarded plastics, so the degradation is poor, the environment is polluted, and there is a fatal problem of unstable fertilizer release. The initial release is very fast (caused by surface defects), and the later release is slow. Very slow, the resulting curve is fast first and then slow, just the opposite of the S-curve that plants like

The main problem of sulfur-coated urea using sulfur is that sulfur is easy to be brittle. Once broken, it is as if it is not coated; if it is not broken, nutrients will not be released. The shortest release period is 7 days, and the release period can reach 180 days through modification. Technology and materials The requirements are high, so the price is expensive, and it is difficult to promote and apply at home and abroad

Resin coatings, such as polyurethane materials, alkyd resins, epoxy resin materials, etc., can achieve sustained release without being affected by soil moisture. The release rate of the day and night is less than 15%, and the release rate of one month is less than 75%. The release rate during the growth period is not less than 80%; but the disadvantage is that the price is high and the degradation is poor. Generally, the market price is 20,000-30,000 yuan per ton

In addition, the soil produced by long-term application of resin coating still has certain ecological risks; The surrounding accumulation affects the absorption of other elements by plants. In addition, the degradation time of the cellulose coating is uncertain, which makes it difficult to control the fertilizer effect time

Therefore, the common disadvantages of several commonly used coated fertilizers are high cost and difficulty in controlling the release rate, which limits their large-scale promotion and has no effect on improving the soil environment.

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