A method for preparing a multifunctional slow-release fertilizer

Abstract

This invention discloses a method for preparing a multifunctional slow-release fertilizer. First, a porous carrier is prepared by co-precipitation and calcination of iron tailings acid leaching solution and aluminum salts. Nutrient solution is loaded onto the carrier, dried, and granulated to obtain fertilizer particles. A bio-based composite coating precursor solution is prepared by mixing nanocellulose whiskers, sodium alginate, polyacrylic acid, and fumed silica, and a calcium chloride-chitosan solution is used as a crosslinking agent to obtain fertilizer particles. Finally, fluidized bed coating technology is used to sequentially spray the coating precursor solution and crosslinking agent solution onto the surface of the fertilizer particles. After two coating processes and drying, a multifunctional slow-release fertilizer is obtained. This invention combines the preparation of an industrial solid waste resource utilization carrier, the construction of a bio-based composite coating, and a rhizosphere-responsive slow-release design to prepare a multifunctional slow-release fertilizer. This fertilizer not only has low preparation cost but is also rich in nutrients, has good slow-release performance, and excellent mechanical stability.

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