Acidic biochar fertilizer suitable for saline-alkali soil and preparation method thereof

Abstract

The invention discloses an acidic biochar fertilizer suitable for saline-alkali soil and a preparation method thereof. The acidic biochar fertilizer comprises biochar as a raw material. The method comprises the following steps: drying yak manure, crushing and sieving the manure; mixing the sieved yak manure with deionized water, putting the mixture into a hydrothermal reaction kettle, and carryingout a hydrothermal reaction; washing the hydrothermal solution obtained after the reaction is finished with absolute ethyl alcohol until the hydrothermal solution is colorless; washing the hydrothermal solution with distilled water until the hydrothermal solution is neutral, then carrying out suction filtration, and drying the solid product to obtain biochar; mixing the biochar with a nitric acidsolution, oscillating the mixture, washing the mixture with deionized water, regulating the pH value, carrying out suction filtration, drying, sieving to obtain acidic biochar, granulating the acidicbiochar with a disc granulator, and drying to obtain the acidic biochar fertilizer. The method is simple, controllable and easy to implement; the acidic biochar fertilizer prepared by the invention can reduce the pH of saline-alkali soil and improve the quality of cultivated land; the biomass resource utilization efficiency is improved, and the solid waste environmental pollution is reduced.

Description

technical field [0001] The invention relates to the technical field of fertilizers, in particular to an acidic biochar fertilizer suitable for saline-alkali soil and a preparation method thereof. Background technique [0002] The area of ​​saline-alkali land in my country is large, about 3.5×10 8 hm 2 , accounting for 36% of the country's cultivated land, widely distributed and of various types. The low soil productivity, microbial diversity and organic matter content caused by soil salinization have exacerbated the deterioration of the ecological environment and hindered the development of agricultural production, and the application of traditional fertilizers often aggravates the degree of soil salinization. The annual output of yak manure in my country is large, and the problem of its resource utilization needs to be solved urgently. Under the current requirements of environmental protection and circular economy, it is an important research to develop a fertilizer and p...

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Problems solved by technology

Chinese patent application CN104211545A discloses a special biochar-based organic-inorganic compound fertilizer for acidic soil and its preparation method. The method utilizes the alkaline characteristics of traditional biochar and uses it as a controlled-release material and adsorption material together with urea and phosphoric acid. Combining ammonium and other substances to prepare compound fertilizer can increase soil pH and effectively improve acidic soil, but it is limited in saline-alkali soil due to its alkaline characteristics

Chinese patent application CN 105542785A discloses an alkaline soil improver and its preparation method. The method is made of phosphoric acid, furfural residue, wheat flour and ammonium phosphate in specific proportions. It has the advantage of simple preparation, but it cannot Significantly lowers the pH of the soil and does not provide enough organic matter for saline-alkali soils

At the same time, hydrothermal carbon itself will have a small amount of acidic functional groups to reduce the pH of alkaline soils, but the ability to reduce soil pH is limited, and after being applied to the soil, it will slowly become alkaline over time, and cannot achieve long-term improvement.

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