The invention discloses a preparation method of an anaerobic self-chelating organic water-soluble
fertilizer, and belongs to the technical field of agricultural organic water-soluble
fertilizer preparation. The method comprises the following steps: crushing and
tempering organic wastes, mixing the organic wastes with a nano confinement carrier with specific pore sizes and surface functional groups, and constructing a
biological membrane in an
anaerobic reactor; then carrying out mineralization reaction, automatically triggering a self-
chelation reconstruction program by monitoring the concentration of short-chain
fatty acid on line, and carrying out directional
chelation and self-
assembly on endogenous metabolites and
nutrient ions in a nano confinement space under the guidance of a carrier; and finally, separating, sterilizing and concentrating to obtain a finished product. On the premise of not depending on an exogenous chelating agent, the organic-inorganic composite nano
fertilizer with the average particle size being 80-150 nm, the proportion of
chelated zinc being larger than or equal to 82% and the proportion of chelated
phosphorus being larger than or equal to 68% is prepared, the 30-day
nitrogen and
phosphorus leaching rates of the organic-inorganic composite nano fertilizer are lower than 17.0% and 11.5% respectively, and the organic-inorganic composite nano fertilizer has good slow release performance and agricultural yield increasing effect and has good application prospects. And a brand new technical approach is provided for high-value
resource utilization of organic wastes.