pH-sensitive coated slow-release phosphate fertilizer and preparation method thereof

Abstract

The invention provides pH-sensitive coated slow-release phosphate fertilizer and a preparation method thereof. The pH-sensitive coated slow-release phosphate fertilizer is prepared by uniformly spraying a coating layer having pH sensibility on surfaces of phosphate fertilizer-phosphate solubilizing microbial inoculum mixture particles. Crops lack of phosphor secretes a large amount of organic acid so that a pH value around the roots is reduced, and aiming at solving the above mechanism, the pH-sensitive coated slow-release phosphate fertilizer can greatly swell according to pH value decreasing so that a large amount of phosphor is released. The pH-sensitive coated slow-release phosphate fertilizer can control release of phosphor according to different phosphor requirement amounts of crops in different growth stages, can timely supply an appropriate amount of phosphor for plants and solves the problem of mismatching of a fertilizer release amount of the existing slow-release fertilizer and crop growth requirements in different stages.

Description

technical field [0001] The invention relates to the field of phosphate fertilizers, in particular to a pH-sensitive coated slow-release phosphate fertilizer and a preparation method thereof. Background technique [0002] Phosphorus is one of the essential nutrients for the growth of crops. The crops have a certain demand for phosphorus throughout the growth cycle. However, after the phosphorus fertilizer is applied to the soil, only a small amount can be absorbed by the crops, while the rest has not been absorbed by the crops. Utilization is lost in vain due to leaching or being fixed by metal ions, resulting in loss of phosphate fertilizer. Develop and apply slow-release phosphate fertilizers to prolong the release time of phosphate fertilizers, so that phosphate fertilizers can gradually provide phosphorus to crops during the slow dissolution process, and prevent adverse consequences such as damage to crop seeds, seedlings or burnt leaves due to excessive local concentrat...

AI Technical Summary

Problems solved by technology

The coated phosphate fertilizer obtained by the invention has a slow release in the early stage, but the release of the phosphate fertilizer is difficult to control after the film layer is broken in the later stage, which is easy to cause waste and loss of phosphate fertilizer

[0006] Chinese Patent Publication No. CN103819278A discloses a high-strength urea-formaldehyde slow-release fertilizer and its preparation method. The slow-release fertilizer is synthesized by combining urea-formaldehyde and phosphate fertilizer, and releases phosphorus through the slow decomposition of chemically synthesized substances. Dissolution, in the process of releasing phosphorus from phosphate fertilizer, the release cycle cannot be guaranteed to be synchronized with the plant growth cycle. Although the purpose of slow release of phosphate fertilizer can be achieved, the effective utilization rate of phosphorus cannot be significantly improved.

After the film layer of ordinary coated phosphate fertilizer dissolves or degrades over time, a large amount of phosphate fertilizer is released, and the absorption of crops is slow, which easily causes phosphate fertilizer to be fixed by the soil and reduces the utilization rate of phosphate fertilizer; chemically synthesized phosphate fertilizer is still slowly dissolved over time , slow release of phosphate fertilizer, cannot supply according to the demand of crops for phosphate fertilizer

At present, although fertilizers suitable for saline-alkali land have been developed, the main purpose is to add acid-base substances to adjust the pH of the soil. However, the change of soil pH has certain fluctuations, and the absorption of phosphate fertilizer by crops is closely related to the pH.