Preparation method of biodegradable nitrogen and phosphorus slow-release fertilizer

Abstract

The invention discloses a preparation method of a biodegradable nitrogen and phosphorus slow-release fertilizer and belongs to the field of fertilizer preparation technology. The preparation method comprises the following steps: a) mixing carrageenan, soyabean lecithin, rapeseed oil, a potassium dihydrogen phosphate solution, expanded vermiculite, fish protein powder and sodium stearate, and carrying out ultrasonic dispersion; b) coating a fertilizer master batch A with the mixed liquor, drying and cooling to room temperature so as to prepare fertilizer granules; c) mixing a fertilizer master batch B, expanded corn flour and the fertilizer granules so as to prepare compound fertilizer granules; and d) obtaining beta-cyclodextrin and a potassium nitrate solution, adding the compound fertilizer granules, stirring, drying and cooling to room temperature so as to prepare the biodegradable nitrogen and phosphorus slow-release fertilizer. The method is suitable for preparation of a water-soluble slow-release fertilizer. The coating material is a degradable material and is pollution-free to soil. The technology of the invention is simple and convenient to operate, has short technological cycle, causes no wastes, accords with the ideal of atom economy and environmental protection, and is beneficial to industrial promotion and application.

Description

technical field [0001] The invention relates to the technical field of chemical fertilizer manufacturing, in particular to a preparation method of a biodegradable nitrogen and phosphorus slow-release chemical fertilizer. Background technique [0002] Chemical fertilizers play a pivotal role in agricultural production. As a large agricultural country, my country has a high demand for chemical fertilizers in agricultural production. According to statistics, chemical fertilizers have become the largest material investment in agricultural production, accounting for about 50% of all productive expenditures. The production and usage of chemical fertilizers in my country ranks first in the world, and the output accounts for about 20% of the world's chemical fertilizer production, and the usage has accounted for 28% of the world's chemical fertilizer consumption; however, due to the nature of chemical fertilizers and the requirements for the soil environment, resulting The physical ...

AI Technical Summary

Problems solved by technology

[0003] Slow-release chemical fertilizers have the following advantages: 1) reduce nutrient loss and improve fertilizer utilization, 2) reduce chemical and biological fixation in the soil that causes plants to be unusable, 3) reduce denitrification and nitrogen nitrification Nitrogen loss; however, the existing slow-release fertilizers have the following problems: 1) The film-forming materials of the coating layer are mostly synthetic polymers, which are not easy to biodegrade; 2) Direct use of pure starch or various plant straw powders plus chemical bonding The sustained release period is short or the sustained release rate is difficult to control; 3) The coating materials used are expensive, such as coupling agents such as silane, titanate or aluminate, and the high cost is not conducive to large-scale application