Agricultural and forestry waste carbon-based slow release filter and preparation method thereof

Abstract

The invention discloses an agricultural and forestry waste carbon-based slow release filter and a preparation method thereof. The preparation method comprises the following steps: crushing agricultural and forestry waste into biomass particles, carrying out pyrolysis to prepare charcoal, dissolving monoammonium phosphate and monopotassium phosphate in water to prepare a saturated water solution of monoammonium phosphate and a saturated water solution of monopotassium phosphate, soaking charcoal prepared in step a in the saturated water solution of monoammonium phosphate and the saturated water solution of monopotassium phosphate so that adsorption capacity of charcoal to phosphate radical ions, ammonium ions and potassium ions is up to 80-90% of balanced adsorption capacity, then taking out charcoal, and drying at the drying temperature of 100-105 DEG C until the moisture content of the slow release filter is less than 5%, thus the agricultural and forestry waste carbon-based slow release filter is obtained. The agricultural and forestry waste carbon-based slow release filter disclosed by the invention is low in cost, long in slow release time and good in slow release effect, can be used for long term and can maintain soil fertility for a long time.

Description

Technical field: [0001] The invention relates to a fertilizer and a preparation method thereof, in particular to an agricultural and forestry waste carbon-based slow-release fertilizer and a preparation method thereof. Background technique: [0002] The earliest slow-release fertilizers were slightly soluble fertilizers, such as urea-formaldehyde and other urea-formaldehyde condensates and compounds that were mainly chemically degraded (such as isobutylene cyclic diurea). Slightly soluble fertilizers are mainly slightly soluble organic nitrogen compounds, which mainly provide nitrogen nutrients. The proportion of nitrogen provided by the low-molecular-weight urea-formaldehyde part exceeds the amount required by the crops in the early stage of crop growth. However, the high-molecular-weight part provides nitrogen too slowly. The release characteristics are not well suited to the needs of crop growth. Subsequently, a kind of physical barrier control fertilizer was developed, ...

AI Technical Summary

Problems solved by technology

Slightly soluble fertilizers are mainly slightly soluble organic nitrogen compounds, which mainly provide nitrogen nutrients. The proportion of nitrogen provided by the low-molecular-weight urea-formaldehyde part exceeds the amount required by the crops in the early stage of crop growth. However, the high-molecular-weight part provides nitrogen too slowly. Release characteristics are not well suited to crop growth needs

Subsequently, a kind of physical barrier control fertilizer was developed, such as coated granular fertilizer and matrix compound fertilizer. However, the coating material of this kind of fertilizer is made of non-degradable polymer, which is easy to remain in the soil and cause pollution and soil degradation.