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CN-122012112-A - Preparation method and application of calcium-phosphorus-loaded hydrothermal humic carbon-based soda saline-alkali soil slow-release conditioner

CN122012112ACN 122012112 ACN122012112 ACN 122012112ACN-122012112-A

Abstract

A preparation method and application of a calcium-phosphorus-loaded hydrothermal humic carbon-based soda saline-alkali soil slow-release conditioner belong to the technical field of soda saline-alkali soil restoration and fertilizer. The invention aims to solve the problems that the modifier used in the existing soda saline-alkali soil modification technology has short effective period, is inconvenient to transport and apply, can possibly cause secondary environmental risks and can not cooperate to continuously provide nutrients such as phosphorus for soil. The method comprises the steps of preparing phosphorus-rich hydrothermal humic carbon, preparing sepiolite modified phosphorus-rich hydrothermal humic carbon, and preparing a crosslinked protective layer. The invention breaks through the limitation of single function of the traditional saline-alkali soil restoration technology, develops the soda saline-alkali soil conditioner which is green, low in cost, easy to apply, high in stability, high in Na + , high in pH and capable of responding to multiple environments of 'phosphorus starvation', solves the problem of 'phosphorus starvation' of the restored soil while reducing the saline-alkali hazard of the soil, and provides a green sustainable solution for soda saline-alkali soil treatment.

Inventors

  • GAI SHUANG
  • YANG FAN
  • XU XINRU
  • BAI XUECHEN
  • Lou Fangjun

Assignees

  • 东北农业大学

Dates

Publication Date
20260512
Application Date
20260224

Claims (10)

  1. 1. The preparation method of the calcium-phosphorus-loaded hydrothermal humic carbon-based soda saline-alkali soil slow-release conditioner is characterized by comprising the following steps of: 1. Mixing straw powder, an alkaline activator and deionized water, transferring the mixture into a high-pressure reaction kettle for hydrothermal humification reaction, filtering the mixture after the reaction is finished, collecting a solid product, drying and grinding the solid product to obtain hydrothermal humic carbon; 2. Compounding sepiolite and acetic acid solution by an impregnation method, filtering after the reaction is finished, collecting a solid product, washing and drying the solid product to obtain activated sepiolite, and performing ball milling reaction on the phosphorus-rich hydrothermal humic carbon and the activated sepiolite to obtain sepiolite modified phosphorus-rich hydrothermal humic carbon; 3. crosslinking the sepiolite modified phosphorus-rich hydrothermal humic carbon, alginate and Ca 2+ solution, continuously stirring at room temperature for reaction, filtering, washing and drying to obtain the calcium-phosphorus-loaded hydrothermal humic carbon-based soda saline-alkali soil slow-release conditioner.
  2. 2. The method for preparing the calcium-phosphorus-loaded hydrothermal humic carbon-based soda saline-alkali soil slow-release conditioner according to claim 1, wherein the alkaline activator in the step one is calcium hydroxide.
  3. 3. The preparation method of the calcium-phosphorus-loaded hydrothermal humic carbon-based soda saline-alkali soil slow-release conditioner is characterized in that the volume ratio of the mass of calcium superphosphate to deionized water in the aqueous solution of the calcium superphosphate in the first step is (2 g-5 g) (10 mL-20 mL).
  4. 4. The preparation method of the calcium-phosphorus-loaded hydrothermal humic carbon-based soda saline-alkali soil slow-release conditioner is characterized in that the volume ratio of the mass of the hydrothermal humic carbon to the volume of the aqueous solution of superphosphate in the first step is (9 g-20 g) (10 mL-20 mL).
  5. 5. The preparation method of the calcium-phosphorus-loaded hydrothermal humic carbon-based soda saline-alkali soil slow-release conditioner is characterized in that the mass ratio of the phosphorus-rich hydrothermal humic carbon to the activated sepiolite in the second step is (1-2) (1-6).
  6. 6. The preparation method of the calcium-phosphorus-loaded hydrothermal humic carbon-based soda saline-alkali soil slow-release conditioner is characterized in that in the second step, the rotational speed of ball milling reaction of the phosphorus-rich hydrothermal humic carbon and activated sepiolite is 200 r/min-500 r/min, and the time is 1 h-5 h.
  7. 7. The preparation method of the calcium-phosphorus-loaded hydrothermal humic carbon-based soda saline-alkali soil slow-release conditioner is characterized in that the Ca 2+ solution in the step three is one or more of a calcium sulfate solution, a calcium chloride solution and a calcium nitrate solution, and the concentration is 0.04 mol/L-0.08 mol/L.
  8. 8. The preparation method of the calcium-phosphorus-loaded hydrothermal humic carbon-based soda saline-alkali soil slow-release conditioner is characterized in that the mass volume ratio of sepiolite modified phosphorus-rich hydrothermal humic carbon to alginate to Ca 2+ solution in the step three is (3 g-5 g) (0.3 g-0.6 g) (100 mL-200 mL).
  9. 9. The preparation method of the calcium-phosphorus-loaded hydrothermal humic carbon-based soda saline-alkali soil slow-release conditioner is characterized in that the continuous stirring reaction time at room temperature in the step three is 0.3-0.5 h.
  10. 10. The application of the calcium-phosphorus-loaded hydrothermal humic carbon-based soda saline-alkali soil slow-release conditioner prepared by the preparation method of any one of claims 1-9, which is characterized in that the conditioner is used for repairing soda saline-alkali soil.

Description

Preparation method and application of calcium-phosphorus-loaded hydrothermal humic carbon-based soda saline-alkali soil slow-release conditioner Technical Field The invention belongs to the technical field of soda saline-alkali soil restoration and fertilizer, and particularly relates to a preparation method and application of a calcium-phosphorus-loaded hydrothermal humic carbon-based soda saline-alkali soil slow-release conditioner. Background Soda saline-alkali soil belongs to a typical ecological fragile soil, and the formation of the soil is combined by groundwater salt migration and strong evaporation, and is mainly distributed in arid and semiarid regions worldwide. The soil is rich in sodium carbonate and sodium bicarbonate, and has the characteristics of strong alkalinity, dispersion of soil colloid, weak water permeability, hardening of plough layers and the like, so that the problems of plant root system development resistance, soil nutrient imbalance, microbial activity inhibition and the like are caused. However, although the traditional calcium-based restoration agent (such as gypsum, desulfurized gypsum and the like) can reduce the pH and sodium adsorption ratio of soil through ion exchange, phosphorus fixation is easy to occur in the implementation process, and a large amount of introduced calcium ions are combined with quick-acting phosphate fertilizer in an alkaline environment to form insoluble calcium phosphate precipitation, so that the effective phosphorus content of the soil is rapidly reduced, secondary nutrition disorder is caused, the problem of phosphorus starvation is generally caused in the saline-alkali soil, and the normal growth of crops after the saline-alkali soil is seriously restricted. In addition, the traditional modifier has single function, the action mechanism is passive and fixed, and the slow release and dynamic regulation and control functions on key ions such as calcium, phosphorus and the like are lacked, so that the improvement on the soil structure and nutrient holding capacity is limited, and the improvement effect is difficult to last. Under the background, developing an intelligent soda saline-alkali soil conditioner which is green, efficient, low in cost, easy to apply, high in stability and capable of responding to multiple environments of high Na +, high pH and 'phosphorus starvation' has become a research hot spot in the current saline-alkali soil treatment field. Disclosure of Invention The invention aims to solve the problems that the modifier used in the existing soda saline-alkali soil modification technology has short effective period, is inconvenient to transport and apply, possibly causes secondary environmental risks and can not cooperate to continuously provide nutrients such as phosphorus for soil, and provides a preparation method and application of a calcium-phosphorus-loaded hydrothermal humic carbon-based soda saline-alkali soil slow-release conditioner. The invention creatively compounds specific modified natural minerals, organic active components and phosphorus activation carriers to obtain the granular intelligent soda saline-alkali soil slow-release conditioner which has the functions of alkali reduction, water retention, ion slow release and phosphorus fertilizer activation, promotes the formation of soil aggregate structures through a synergistic action mechanism, effectively breaks hardening, effectively reduces the process of soil salinization, can synchronously regulate and control the conversion path of phosphorus, slows down the fixing rate of the phosphorus to indissolvable calcium phosphate, thereby obviously improving the utilization efficiency and sustainability of phosphorus and providing a new path for sustainable treatment of soda saline-alkali soil. The preparation method of the calcium-phosphorus-loaded hydrothermal humic carbon-based soda saline-alkali soil slow-release conditioner is completed according to the following steps: 1. Mixing straw powder, an alkaline activator and deionized water, transferring the mixture into a high-pressure reaction kettle for hydrothermal humification reaction, filtering the mixture after the reaction is finished, collecting a solid product, drying and grinding the solid product to obtain hydrothermal humic carbon; 2. Compounding sepiolite and acetic acid solution by an impregnation method, filtering after the reaction is finished, collecting a solid product, washing and drying the solid product to obtain activated sepiolite, and performing ball milling reaction on the phosphorus-rich hydrothermal humic carbon and the activated sepiolite to obtain sepiolite modified phosphorus-rich hydrothermal humic carbon; 3. crosslinking the sepiolite modified phosphorus-rich hydrothermal humic carbon, alginate and Ca 2+ solution, continuously stirring at room temperature for reaction, filtering, washing and drying to obtain the calcium-phosphorus-loaded hydrothermal humic carbon-based soda saline-a