Soil improvement fertilizer for improving survival rate of vegetation in semi-arid region and preparation method of soil improvement fertilizer

Abstract

The invention provides a soil improvement fertilizer for improving the survival rate of vegetation in a semi-arid region and a preparation method of the soil improvement fertilizer, and belongs to the technical field of improved fertilizers. According to the soil improvement fertilizer provided by the invention, the organic matrix activation material is utilized to quickly supplement soil organic matters, quickly reconstruct a soil aggregate structure and promote microbial proliferation, so that the soil fertility is improved; the water retention composite material integrates an automatic water retention function, and invalid evaporation of soil moisture is reduced; the functional microbial agent can activate the activity of local microorganisms in soil, so that the soil fertility is improved in a short time; sand grains can be rapidly bonded in the mineral conditioner to form aggregates, desertification is relieved, and a loose environment is provided for rapid rooting of vegetation roots in cooperation with the organic matrix activating material and the local functional fungicide; the slow-release nutrient carrier can improve soil fertility in a short time, continuously provides nutrients for growth of vegetation in a seedling stage and improvement of soil microbial activity, avoids rapid loss of the nutrients, and assists in activating native microorganisms.

Description

Technical Field

[0001] This invention relates to the field of improved fertilizer technology, and in particular to a soil improver fertilizer for improving the survival rate of vegetation in semi-arid regions and its preparation method. Background Technology

[0002] The soils in semi-arid regions generally suffer from the core problems of structural degradation (sandification, compaction) and extremely low organic matter content, which directly lead to low vegetation survival rates and great difficulty in ecological restoration. The existing soil improvement technologies for the above problems mainly include large-scale application of organic fertilizer, mechanized straw return to the field, application of soil structure improvers, and perennial herb rotation, but these technologies all have the following technical problems that are difficult to avoid: (1) slow effect and long cycle: soil organic matter improvement and aggregate structure repair require continuous implementation for more than 2 to 3 years to show obvious effects. After planting, it is difficult for vegetation to quickly obtain a suitable soil environment for growth, resulting in low survival rate in the early stage; (2) high cost and low input-output ratio: the prices of commercial organic fertilizers, biological agents, chemical improvers and other materials are high, and the equipment matching costs for large-scale application are also high. The ecological benefits of vegetation planting in the region have a long conversion cycle and low economic returns, resulting in insufficient willingness among farmers and ecological restoration entities to promote it; (3) The effect is significantly constrained by water: semi-arid areas have scarce rainfall and dry soil. Existing improvement technologies rely on soil moisture to achieve organic matter decomposition and microbial activation. In dry years, the effect of the improver is greatly reduced or even completely ineffective; (4) Poor technology adaptability: a single improvement material can only solve a single problem (such as PAM only prevents desertification and gypsum only dissolves compaction). It cannot simultaneously achieve the synergistic effect of "improving structure, increasing organic matter, retaining water and fertilizer, and promoting vegetation rooting". Multiple technologies need to be combined and applied, which further increases the difficulty and cost of operation. Therefore, developing a soil improvement fertilizer that can quickly improve the structure of sandy / compacted soil in semi-arid areas, quickly increase soil organic matter, and at the same time have self-water retention capacity, reduce water dependence, and has controllable cost and strong adaptability is a technical problem that urgently needs to be solved in the field of ecological restoration and vegetation planting in semi-arid areas. It is also a key breakthrough to improve the survival rate of vegetation. Summary of the Invention

[0003] The purpose of this invention is to provide a soil amendment fertilizer for improving the survival rate of vegetation in semi-arid regions and its preparation method. The soil amendment fertilizer provided by this invention can quickly improve the structure of sandy / compacted soil in semi-arid regions, rapidly increase soil organic matter, and at the same time have self-water retention capacity, reduce water dependence, and have controllable cost and strong adaptability.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0005] This invention provides a soil amendment fertilizer for improving the survival rate of vegetation in semi-arid regions. It is prepared by weight of the following raw materials: 24-60 parts of organic matrix activator, 20-35 parts of water-retaining composite material, 3-14 parts of functional microbial agent, 7-25 parts of mineral conditioner, 3-12 parts of slow-release nutrient carrier, and 0.6-4 parts of adjuvant.

[0006] The organic matrix activator is made by mixing straw and livestock manure with humic acid after they have been composted with a rapid composting agent; the water-retaining composite material is prepared by biochar-supported modified sodium polyacrylate; and the slow-release nutrient carrier is obtained by coating amino acid compound fertilizer with a starch-polyvinyl alcohol composite film.

[0007] Preferably, the product is prepared by weight of the following raw materials: 30-50 parts of organic matrix activator, 22-30 parts of water-retaining composite material, 5-10 parts of functional microbial agent, 10-20 parts of mineral conditioner, 5-10 parts of slow-release nutrient carrier, and 1-3 parts of additives.

[0008] Preferably, the modified sodium polyacrylate is obtained by modifying sodium polyacrylate by gamma ray irradiation.

[0009] Preferably, the functional bacterial agent is prepared by mixing Bacillus subtilis, phosphorus-solubilizing and potassium-solubilizing bacteria, and nitrogen-fixing bacteria screened locally in semi-arid regions.

[0010] Preferably, the additives include at least one of sodium lignosulfonate, sodium naphthalenesulfonate formaldehyde condensate, sodium polyacrylate, and sodium carboxymethyl cellulose.

[0011] This invention also provides a method for preparing the soil amendment fertilizer for improving vegetation survival rate in semi-arid regions as described in the above technical solution, comprising the following steps:

[0012] (1) Mix straw, livestock and poultry manure and rapid composting agent, compost and dry them in sequence, then mix them with humic acid and crush them first to obtain organic matrix activated material;

[0013] (2) Sodium polyacrylate was modified by γ-ray irradiation and dispersed in water to obtain a modified sodium polyacrylate solution;

[0014] Biochar and the modified sodium polyacrylate solution were mixed and then subjected to ultrasonication, drying, and second pulverization in sequence to obtain a water-retaining composite material.

[0015] (3) Prepare a coating solution using corn starch, polyvinyl alcohol, plasticizer and emulsifier, and then coat it with amino acid compound fertilizer to obtain a slow-release nutrient carrier;

[0016] The organic matrix activator obtained in step (1) and the water-retaining composite material obtained in step (2) are mixed with the mineral conditioner, the slow-release nutrient carrier, and the additives, and stirred to obtain a mixture.

[0017] (4) Add the functional microbial agent to the mixture obtained in step (3), and carry out fermentation, granulation and drying in sequence to obtain a soil improvement fertilizer for improving the survival rate of vegetation in semi-arid areas.

[0018] Preferably, the parameters for the composting in step (1) include: controlling the moisture content of the material to be 60%~65%, the composting temperature to be 50~60℃, and the composting time to be 7~10 days.

[0019] Preferably, the parameters of the γ-ray irradiation in step (2) include: the irradiation dose of the γ-ray irradiation equipment used is 20~30kGy, the irradiation temperature is 25~30℃, and the irradiation treatment time in an air atmosphere is 1~2h.

[0020] Preferably, in step (3), the amino acid compound fertilizer is composed of urea, potassium dihydrogen phosphate, amino acid raw powder, EDTA-zinc, boric acid, and magnesium sulfate in a mass ratio of (2~5):(1~3):(0.8~1.2):0.5:0.3:0.2.

[0021] Preferably, the fermentation parameters in step (4) include: controlling the moisture content of the material to be 20-25%, the fermentation temperature to be 25-30℃, and the fermentation time to be 20-28h.

[0022] This invention provides a soil amendment fertilizer for improving vegetation survival rates in semi-arid regions. It achieves stable bonding between rapidly decomposed organic matrix activation material and water-retaining composite materials through biochar loading. Simultaneously, it screens native functional bacteria from semi-arid regions to enhance compatibility, solving the problems of separation between organic matter replenishment and water retention functions, and low survival rates of introduced microorganisms in existing technologies. Utilizing rapid decomposition, low-temperature fermentation, and granulation, the organic matrix decomposition cycle is shortened while ensuring the activity of functional bacteria, representing a fundamental difference from existing organic fertilizer preparation processes (traditional composting and high-temperature sterilization). In existing technologies, soil amendment, water retention, and microbial agent application are mostly independent techniques. This invention, based on the synergistic degradation characteristics of drought, poor structure, and low fertility in semi-arid soils, integrates structural improvement, organic matter replenishment, water retention, and nutrient activation, achieving functional synergy through optimized raw material ratios and process innovation. The use of biochar-loaded modified sodium polyacrylate improves both water retention stability and soil permeability. The screening and application of functional microbial agents solves the problems of low survival rates and unstable effects of introduced microorganisms in semi-arid soils. To address the ecological degradation problem in semi-arid regions, this invention innovatively develops water-retaining and slow-release soil amendment fertilizers, constructs a soil-vegetation synergistic restoration system, and establishes a technical model for improving vegetation survival rate through research on the coupling mechanism of soil structure improvement and vegetation adaptability regulation, thus forming a low-cost and high-efficiency ecological restoration solution. Attached Figure Description

[0023] Figure 1 The image shows the survival rate of vegetation in a semi-arid region 90 days after application of the fertilizers in Examples 1-4 and Comparative Examples 1 and 2 of this invention. Detailed Implementation

[0024] This invention provides a soil amendment fertilizer for improving the survival rate of vegetation in semi-arid regions. It is characterized by comprising, by weight, the following raw materials: 24-60 parts of organic matrix activator, 20-35 parts of water-retaining composite material, 3-14 parts of functional microbial agent, 7-25 parts of mineral conditioner, 3-12 parts of slow-release nutrient carrier, and 0.6-4 parts of adjuvant.

[0025] The organic matrix activator is made by mixing straw and livestock manure with humic acid after they have been composted with a rapid composting agent; the water-retaining composite material is prepared by biochar-supported modified sodium polyacrylate; and the slow-release nutrient carrier is obtained by coating amino acid compound fertilizer with a starch-polyvinyl alcohol composite film.

[0026] Unless otherwise specified, all raw materials used in this invention are commercially available products in the art.

[0027] In this invention, the soil amendment fertilizer for improving the survival rate of vegetation in semi-arid regions, by weight, is preferably prepared from the following raw materials: 30-50 parts of organic matrix activator, 22-30 parts of water-retaining composite material, 5-10 parts of functional microbial agent, 10-20 parts of mineral conditioner, 5-10 parts of slow-release nutrient carrier, and 1-3 parts of adjuvant.

[0028] In this invention, the functional microbial agent is preferably prepared by mixing Bacillus subtilis, phosphate-solubilizing and potassium-solubilizing bacteria, and nitrogen-fixing bacteria screened locally from semi-arid regions. In this invention, the functional microbial agent is preferably obtained by mixing Bacillus subtilis solution, phosphate-solubilizing and potassium-solubilizing bacteria solution, and nitrogen-fixing bacteria solution in a volume ratio of (1~3):1:1; the viable count of the Bacillus subtilis solution is preferably ≥2.0 × 10⁻⁶. 9 CFU / mL; the viable count of the phosphorus- and potassium-solubilizing bacterial solution is preferably ≥1.0 × 10⁻⁶. 9 CFU / mL; the viable count of the nitrogen-fixing bacterial solution is preferably ≥1.5×10⁻⁶. 9 CFU / mL. This invention does not impose any particular limitation on the screening method; any technical solution well-known in the art can be used. In this invention, the adjuvant preferably includes at least one of sodium lignosulfonate, sodium naphthalenesulfonate formaldehyde condensate, sodium polyacrylate, and sodium carboxymethyl cellulose.

[0029] This invention also provides a method for preparing the soil amendment fertilizer for improving vegetation survival rate in semi-arid regions as described in the above technical solution, comprising the following steps:

[0030] (1) Mix straw, livestock and poultry manure and rapid composting agent, compost and dry them in sequence, then mix them with humic acid and crush them first to obtain organic matrix activated material;

[0031] (2) Sodium polyacrylate was modified by γ-ray irradiation and dispersed in water to obtain a modified sodium polyacrylate solution;

[0032] Biochar and the modified sodium polyacrylate solution were mixed and then subjected to ultrasonication, drying, and second pulverization in sequence to obtain a water-retaining composite material.

[0033] (3) Prepare a coating solution using corn starch, polyvinyl alcohol, plasticizer and emulsifier, and then coat it with amino acid compound fertilizer to obtain a slow-release nutrient carrier;

[0034] The organic matrix activator obtained in step (1) and the water-retaining composite material obtained in step (2) are mixed with the mineral conditioner, the slow-release nutrient carrier, and the additives, and stirred to obtain a mixture.

[0035] (4) Add the functional microbial agent to the mixture obtained in step (3), and carry out fermentation, granulation and drying in sequence to obtain a soil improvement fertilizer for improving the survival rate of vegetation in semi-arid areas.

[0036] This invention mixes straw, livestock and poultry manure and a rapid composting agent, performs composting and drying in sequence, mixes it with humic acid, and then crushes it to obtain an organic matrix activated material.

[0037] In this invention, the preferred mass ratio of straw to livestock manure is (1.5~3):1, more preferably 2:1. In this invention, the rapid composting agent is preferably EM (Effective Microorganisms) inoculant; the mass of the rapid composting agent is 0.3%~0.5% of the total mass of the straw and livestock manure. In this invention, the composting parameters preferably include: controlling the material moisture content to 60~65%, the composting temperature to 50~60℃, and the composting time to 7~10 days; more preferably, controlling the material moisture content to 63%, the composting temperature to 55℃, and the composting time to 9 days. This invention promotes rapid composting by controlling the composting parameters within the above ranges, transforming straw and livestock manure into nutrient-rich organic matter. In this invention, the drying is preferably performed until the moisture content is ≤15%. In this invention, the first pulverization is preferably performed using an ultrafine pulverizer to grind to a particle size ≤100 mesh.

[0038] In this invention, sodium polyacrylate is modified by γ-ray irradiation and dispersed in water to obtain a modified sodium polyacrylate solution; biochar and the modified sodium polyacrylate solution are mixed and then subjected to ultrasonication, drying and second pulverization to obtain a water-retaining composite material.

[0039] In this invention, the sodium polyacrylate is preferably in powder form; the molecular weight of the sodium polyacrylate is preferably 8-10 million. In this invention, the parameters of the gamma-ray irradiation preferably include: an irradiation dose of 20-30 kGy using the gamma-ray irradiation equipment, an irradiation temperature of 25-30°C, and an irradiation time of 1-2 hours in an air atmosphere. This invention modifies the sodium polyacrylate molecular chain by gamma-ray irradiation, improving its biocompatibility and degradability in soil environments while retaining its high water absorption capacity. In this invention, the dispersion of the modified polyacrylate in water preferably includes: adding the modified sodium polyacrylate obtained by gamma-ray irradiation to deionized water, stirring at a stirring speed of 200-250 r / min and a temperature of 40-50°C for 30-40 minutes, and allowing it to stand and cool to room temperature to obtain a modified sodium polyacrylate solution with a mass concentration of 4%-6%. In this invention, the biochar is preferably prepared from corn cobs. In this invention, the preferred method for preparing the biochar includes the following steps: Corn cobs are removed of impurities and pulverized to a particle size of 2-5 mm. The cobs are placed in a tube furnace, and nitrogen gas (purity ≥99.9%) is introduced to purge the air inside the furnace for 5-10 minutes. Then, the temperature is increased to 500-600°C at a rate of 10-15°C / min, and pyrolysis is performed under anaerobic conditions (nitrogen flow rate 50-80 mL / min) for 1-3 hours. After pyrolysis, the cochar is naturally cooled to room temperature and ground to a particle size ≤100 mesh to obtain the biochar. In this invention, the preferred mass ratio of the biochar to the volume of the modified sodium polyacrylate solution is 1 g:(16-25) mL. In this invention, the preferred ultrasonic power is 200-300 W; the preferred ultrasonic frequency is 30-40 kHz; and the preferred ultrasonic time is 20-30 minutes. This invention utilizes ultrasound to fully adsorb the modified sodium polyacrylate into the porous structure of the biochar. In this invention, the drying method is preferably to dry at 75~80℃ to constant weight, and weigh every 2 hours. The difference between two weighings is ≤0.5% to be considered constant weight. In this invention, the second pulverization method is preferably to grind to a particle size ≤80 mesh using an ultrafine pulverizer.

[0040] This invention utilizes corn starch, polyvinyl alcohol, plasticizer, and emulsifier to prepare a coating solution, which is then used to coat an amino acid compound fertilizer to obtain a slow-release nutrient carrier.

[0041] In this invention, the preferred mass ratio of corn starch to polyvinyl alcohol is (2~4):1, more preferably 3:1. In this invention, the preferred degree of polymerization of polyvinyl alcohol is 1700~1800. In this invention, the preferred plasticizer is glycerol; the preferred emulsifier is Tween-80. In this invention, the preparation method of the coating solution preferably includes the following steps: mixing corn starch, polyvinyl alcohol, and deionized water, controlling the ratio of the total mass of corn starch and polyvinyl alcohol to the volume of deionized water to be 1g:(12~18)mL, first stirring and gelatinizing at a stirring speed of 100~150r / min and 90~95℃ for 20~40min, then cooling to 50~60℃, adding 0.5% glycerol (plasticizer) and 0.3% Tween-80 (emulsifier) ​​of the total mass of the coating solution, and continuing stirring for 15~25min to obtain a uniform coating solution. In this invention, the amino acid compound fertilizer is preferably composed of urea, potassium dihydrogen phosphate, amino acid raw powder, EDTA-zinc, boric acid, and magnesium sulfate in a mass ratio of (2~5):(1~3):(0.8~1.2):0.5:0.3:0.2. In this invention, the amino acid raw powder is preferably composed of glycine and glutamic acid in a mass ratio of 1:1. In this invention, the preparation method of the amino acid compound fertilizer preferably includes the following steps: mixing urea (nitrogen source), potassium dihydrogen phosphate (phosphorus and potassium source), amino acid raw powder, EDTA-zinc (zinc source), boric acid (boron source), and magnesium sulfate (magnesium source) evenly to obtain a mixture; adding 10~15% of the total mass of the mixture to deionized water; stirring and mixing for 20~30 min at a stirring speed of 150~200 r / min and a temperature of 60~70℃; then feeding the mixture into a granulator to obtain particles with a particle size of 1~3 mm; and finally drying at 55~60℃ until the moisture content is ≤8% to obtain the amino acid compound fertilizer. In this invention, the preferred method for coating the amino acid compound fertilizer includes: controlling the bed temperature at 45-50℃ and the air inlet velocity at 0.8-1.0 m / s, feeding the amino acid compound fertilizer into a fluidized bed coating machine; uniformly spraying the coating solution onto the surface of the amino acid compound fertilizer using a spray system at a mass ratio of 10:3 (amino acid compound fertilizer to coating solution); coating for 30-40 minutes; and drying at 45-50℃ until the moisture content is ≤8% after coating, thus obtaining a slow-release nutrient carrier of amino acid compound fertilizer coated with a starch-polyvinyl alcohol composite film. The slow-release nutrient carrier prepared by this invention achieves slow nutrient release through the slow degradation of the coating material, with a release period of 30-45 days, matching the nutrient requirements of plant seedlings.

[0042] After obtaining the organic matrix activator, the water-retaining composite material, and the slow-release nutrient carrier, the present invention mixes the organic matrix activator and the water-retaining composite material with the mineral conditioner, the slow-release nutrient carrier, and the additives, and then stirs to obtain a mixture.

[0043] In this invention, the mineral conditioner is preferably composed of bentonite and gypsum powder in a mass ratio of (1~3):1. This invention utilizes bentonite to enhance soil cohesion and alleviate desertification, while gypsum powder loosens compacted soil, synergistically improving soil texture. In this invention, the mixing equipment is preferably a twin-screw mixer; the mixing speed is preferably 250~400 r / min; and the mixing time is preferably 16~25 min.

[0044] After obtaining the mixture, the present invention adds functional microbial agents to the mixture, and then carries out fermentation, granulation and drying in sequence to obtain a soil amendment fertilizer for improving the survival rate of vegetation in semi-arid regions.

[0045] In this invention, the fermentation parameters preferably include: controlling the material moisture content to 20-25%, the fermentation temperature to 25-30℃, and the fermentation time to 20-28 hours; stirring once every 6 hours at a speed of 20-50 r / min for 3-6 minutes. This invention, by adjusting the fermentation parameters, ensures that functional bacteria uniformly adhere to the mixture and proliferate rapidly. In this invention, the granulation is preferably performed using a disc granulator to obtain particles with a diameter of 2-5 mm. In this invention, the drying method is preferably low-temperature drying at 40-45℃ until the moisture content is ≤12%.

[0046] This invention provides a soil amendment fertilizer for improving vegetation survival rates in semi-arid regions. It utilizes an organic matrix activator to rapidly replenish soil organic matter (the decomposed organic matrix is ​​rich in humus, directly increasing soil organic matter content) and quickly reconstruct soil aggregate structure (humic acid, as a natural cementing agent, can quickly bind sand particles or loosened, compacted soil particles, forming stable aggregates, alleviating desertification and compaction, and providing a loose environment for plant roots to take root). It also activates the activity of native soil microorganisms; the organic matrix provides carbon and nitrogen sources for native microorganisms, promoting microbial proliferation and thus improving soil fertility. The water-retaining composite material integrates self-retaining water functions. Modified sodium polyacrylate has high water absorption capacity, and the porous structure of biochar can fix the water-retaining agent, preventing loss, while storing water and forming a water-retaining layer, blocking upward migration and evaporation of soil moisture, reducing ineffective evaporation. The stored water can be slowly released for vegetation absorption, reducing the dependence of the amendment effect on natural rainfall. Furthermore, the porous structure of biochar can further enhance soil permeability, supplementing… This invention helps improve soil looseness; the functional microbial agent can activate the activity of native soil microorganisms. Native strains have strong adaptability and high survival rates, allowing for rapid proliferation and activation of the original soil microbial community, thus improving soil fertility in a short period and strengthening soil aggregate structure. The polysaccharides secreted by Bacillus subtilis can assist in cementing soil particles, enhancing aggregate stability and further alleviating desertification and compaction. Mineral conditioners, such as bentonite with strong adsorption and binding properties, can quickly bind sand particles to form aggregates, alleviating desertification. Gypsum powder can loosen compacted clay soil, breaking up the soil compaction layer. Together with organic matrix activators and native functional microbial agents, they provide a loose environment for rapid root development in plants. The slow-release nutrient carrier can improve soil fertility in a short period, slowly releasing nitrogen, phosphorus, potassium, and trace elements, continuously providing nutrients for seedling growth and enhanced soil microbial activity, preventing rapid nutrient loss and assisting in activating native microorganisms. Furthermore, the raw materials used in this invention are widely available, the preparation process is simple, reducing production costs, increasing the input-output ratio, and facilitating large-scale promotion and application.

[0047] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0048] Unless otherwise specified, all experiments were repeated three times, and the results are expressed as averages.

[0049] Example 1

[0050] A soil amendment fertilizer for improving the survival rate of vegetation in semi-arid regions is prepared from the following raw materials: 30 parts of organic matrix activator, 30 parts of water-retaining composite material, 10 parts of functional microbial agent, 20 parts of mineral conditioner, 10 parts of slow-release nutrient carrier, and 3 parts of sodium polyacrylate with a molecular weight of 8000.

[0051] The functional microbial agent is prepared by mixing Bacillus subtilis, phosphorus-solubilizing and potassium-solubilizing bacteria, and nitrogen-fixing bacteria screened locally in semi-arid regions; the functional microbial agent is obtained by mixing Bacillus subtilis solution, phosphorus-solubilizing and potassium-solubilizing bacteria solution, and nitrogen-fixing bacteria solution in a volume ratio of 2:1:1; the viable count of the Bacillus subtilis solution is 3.0 × 10⁻⁶. 9 CFU / mL; the viable count of the phosphorus- and potassium-solubilizing bacterial solution was 2.0 × 10⁻⁶. 9 CFU / mL; the viable count of the nitrogen-fixing bacteria solution was 1.5 × 10⁻⁶. 9 CFU / mL.

[0052] The preparation method of the above-mentioned soil amendment fertilizer for improving vegetation survival rate in semi-arid regions includes the following steps:

[0053] (1) Mix straw and livestock manure at a mass ratio of 2:1, add 0.5% of the total mass of the mixture of straw and livestock manure as a rapid composting agent (EM agent), control the moisture content to 63%, compost at 55℃ for 9 days, dry to a moisture content ≤15% after composting, mix with humic acid, and grind to a particle size ≤100 mesh using an ultra-micro pulverizer to obtain an organic matrix activated material;

[0054] (2) Sodium polyacrylate powder with a molecular weight of 8 million was placed in a γ-ray irradiation device and irradiated for 2 hours under an irradiation dose of 25 kGy, an irradiation temperature of 28℃ and an air atmosphere to obtain modified sodium polyacrylate. Then it was added to deionized water and stirred for 40 minutes under a stirring speed of 250 r / min and a temperature of 50℃. After standing and cooling to room temperature, a modified sodium polyacrylate solution with a mass concentration of 5% was obtained.

[0055] The preparation method of the biochar is as follows: after removing impurities from corn cobs, crush them to a particle size of 2-5 mm, place them in a tube furnace, first purge the air in the furnace with nitrogen gas (purity ≥99.9%) for 8 min, then raise the temperature to 550℃ at a heating rate of 12℃ / min, maintain anaerobic conditions (nitrogen flow rate 60 mL / min) for pyrolysis for 2 h, after pyrolysis, allow to cool naturally to room temperature, grind to a particle size ≤100 mesh to obtain biochar;

[0056] Biochar and the modified sodium polyacrylate solution were mixed and ultrasonicated for 25 minutes at a power of 200W and a frequency of 30kHz. The mixture was then dried at 80℃ to constant weight. The mixture was weighed every 2 hours. The constant weight was defined as the difference between two weighings ≤0.5%. The mixture was then ground in an ultrafine pulverizer to a particle size ≤80 mesh to obtain a water-retaining composite material.

[0057] (3) Mix corn starch, polyvinyl alcohol and deionized water, and control the mass ratio of corn starch and polyvinyl alcohol with a degree of polymerization of 1800 to be 3:1. The total mass of corn starch and polyvinyl alcohol and the volume ratio of deionized water are 1g:15mL. First, stir and gelatinize at a stirring speed of 150r / min and 95℃ for 30min. Then, cool down to 50℃ and add 0.5% of glycerol (plasticizer) and 0.3% of Tween-80 (emulsifier) ​​of the total mass of the coating solution. Continue stirring for 20min to obtain a uniform coating solution.

[0058] Urea, potassium dihydrogen phosphate, amino acid powder composed of glycine and glutamic acid in a mass ratio of 1:1, EDTA-zinc, boric acid, and magnesium sulfate were mixed evenly in a mass ratio of 3.5:1.5:0.8:0.5:0.3:0.2 to obtain a mixture. 15% of the total mass of the mixture was added to deionized water, and the mixture was stirred for 30 minutes at a stirring speed of 200 r / min and a temperature of 70℃. The mixture was then fed into a granulator to obtain granules with a particle size of 2 mm. The granules were then dried at 60℃ to a moisture content of 7% to obtain an amino acid compound fertilizer.

[0059] The amino acid compound fertilizer was fed into a fluidized bed coating machine with the bed temperature controlled at 50℃ and the air inlet speed at 1.0 m / s. The coating liquid was sprayed evenly onto the surface of the amino acid compound fertilizer through a spray system at a mass ratio of 10:3 to amino acid compound fertilizer. The coating time was 35 min. After coating, the fertilizer was dried at 48℃ until the moisture content was 7%, thus obtaining a slow-release nutrient carrier of amino acid compound fertilizer coated with starch-polyvinyl alcohol composite film.

[0060] The organic matrix activator obtained in step (1) and the water-retaining composite material obtained in step (2) are mixed with the mineral conditioner, the slow-release nutrient carrier, and the additives, and then stirred in a double helix mixer at a stirring speed of 300 r / min for 25 min to obtain the mixture.

[0061] The mineral conditioning agent is composed of bentonite and gypsum powder in a mass ratio of 1.5:1;

[0062] (4) Add the functional microbial agent to the mixture obtained in step (3), control the material moisture content to 25%, ferment at 30°C for 24 hours, stir once every 6 hours, stir at 30 r / min for 5 minutes, then granulate with a disc granulator to obtain particles with a particle size of 2-5 mm, dry at 40°C to a moisture content of 11%, and obtain a soil amendment fertilizer for improving the survival rate of vegetation in semi-arid areas.

[0063] Example 2

[0064] A soil amendment fertilizer for improving vegetation survival rate in semi-arid regions, which differs from Example 1 in that it contains 50 parts of organic matrix activator.

[0065] Example 3

[0066] A soil amendment fertilizer for improving vegetation survival rate in semi-arid regions, which differs from Example 1 in that it contains 10 parts of mineral conditioner.

[0067] Example 4

[0068] A soil amendment fertilizer for improving vegetation survival rate in semi-arid regions, which differs from Example 1 in that it contains 5 portions of slow-release nutrient carrier.

[0069] Comparative Example 1

[0070] A soil fertilizer, unlike Example 1, does not contain water-retaining composite material.

[0071] Comparative Example 2

[0072] A soil fertilizer, unlike Example 1, does not contain a slow-release nutrient carrier.

[0073] The survival rate of vegetation and soil indicators in semi-arid regions were tested after applying the fertilizers in the examples and comparative examples, respectively, using the following methods.

[0074] Experimental site: Typical degraded plots in a semi-arid region were selected, and sandy soil experimental areas were set up, with each area being 20m². 2 (4m×5m), plot spacing 1m, 3 replicates; the bulk density of the sandy soil in the sandy soil test area was 1.65g / cm³. 3 The organic matter content is 6.2 g / kg;

[0075] Experimental groups: The fertilizers used in the examples and comparative examples were applied separately, and conventional planting was carried out using a combination of hole application and strip application (80g / hole for planting and 25kg / acre for strip application).

[0076] Planting parameters: In the above-mentioned desertified soil test area, sea buckthorn seedlings were planted in spring (mid to late April) with a plant spacing of 1m×1m and 20 seedlings per area. After planting, the seedlings were watered once to help them establish roots (500mL of water per seedling). No artificial irrigation was carried out afterward, and the seedlings were left to receive natural rainfall.

[0077] 1. Vegetation survival rate test:

[0078] Testing time points: Survival rate was tested three times at 30 days (seedling stage), 60 days (growth stage), and 90 days (survival stabilization stage) after planting;

[0079] Testing procedures: ① Observe the growth status of each seabuckthorn seedling in each plot, using "leaf fully expanded, no wilting or drying, stems without rot, and no loosening when gently pulled" as the survival criteria; ② Count the number of surviving seedlings in each plot and calculate the survival rate: survival rate = (number of surviving seedlings / total number of planted seedlings) × 100%; ③ Take the average survival rate of the three replicate plots as the final survival rate data. The test results are shown in Table 1 and... Figure 1 As shown.

[0080] Table 1. Results of vegetation survival rate testing in semi-arid regions after applying the fertilizers in Examples 1-4 and Comparative Examples 1 and 2.

[0081]

[0082] From Table 1 and Figure 1 It can be seen that after applying the fertilizers in Examples 1-4, the survival rate of vegetation in the semi-arid region was significantly higher than that in Comparative Examples 1 and 2.

[0083] 2. Supporting soil index testing (to verify the correlation between the improvement effect and the survival rate)

[0084] Testing indicators: Soil bulk density (reflecting soil looseness), soil field water holding capacity (reflecting water retention capacity), and soil organic matter content (reflecting fertility improvement effect).

[0085] Sampling method: 90 days after planting, 15cm topsoil samples were collected in each area using the "five-point sampling method". 1kg of soil was collected from each sampling point. After removing stones, roots and other impurities, the soil was mixed evenly to prepare a mixed sample, which was then brought back to the laboratory for testing.

[0086] Specific testing procedures and parameters: (1) Soil bulk density: Using the ring sampler method, take a volume of 100 cm³. 3(1) Soil sample was placed in a ring cutter, and the compaction degree was the same as that in the field. After leveling, it was weighed and the bulk density was calculated as (dry soil mass / ring cutter volume). The dry soil mass was measured by drying in a 105℃ oven to constant weight (the difference between two weighings ≤ 0.5%). (2) Soil field water holding capacity: The indoor ring cutter simulation method was used. The ring cutter containing the soil sample was placed on a sand tray, and water was slowly added until the soil was saturated. After standing for 24 hours, the soil moisture content was measured, which is the field water holding capacity. The moisture content was determined by gravimetric method (drying temperature 105℃, drying time 8h). (3) Soil organic matter content: The potassium dichromate oxidation-external heating method was used. 0.5g of soil sample that passed through a 100-mesh sieve was weighed, and 5mL of potassium dichromate standard solution (0.8mol / L) and 5mL of concentrated sulfuric acid were added. The sample was heated in an oil bath at 170℃ for 5min. After cooling, the organic matter content was calculated by titration with ferrous sulfate standard solution (0.2mol / L). The test results are shown in Table 2.

[0087] Table 2. Soil index test results in semi-arid regions after applying the fertilizers in Examples 1-4 and Comparative Examples 1 and 2.

[0088]

[0089] As shown in Table 2, after applying the fertilizers in Examples 1-4, the soil bulk density in the semi-arid region decreased significantly, while the field water holding capacity and organic matter content increased significantly. This indicates that the soil structure, water retention, and fertility conditions were effectively improved, which is the core reason for the increased vegetation survival rate. The soil-improving fertilizer provided by this invention utilizes organic matrix activators to quickly replenish soil organic matter and rapidly reconstruct the soil aggregate structure, promoting microbial proliferation and thus improving soil fertility. The water-retaining composite material integrates self-retaining water function, reducing ineffective evaporation of soil moisture. The functional microbial agent can activate the activity of native soil microorganisms, achieving a short-term improvement in soil fertility. The mineral conditioner can quickly bind sand particles to form aggregates, alleviating desertification, and, in conjunction with the organic matrix activators and native functional microbial agents, provides a loose environment for rapid root development of vegetation. The slow-release nutrient carrier can improve soil fertility in a short period of time, continuously providing nutrients for the growth of vegetation seedlings and the enhancement of soil microbial activity, avoiding rapid nutrient loss, and assisting in the activation of native microorganisms.

[0090] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A soil amendment fertilizer for improving vegetation survival rate in semi-arid regions, characterized in that, The product is prepared by weight from the following raw materials: 24-60 parts of organic matrix activator, 20-35 parts of water-retaining composite material, 3-14 parts of functional microbial agent, 7-25 parts of mineral conditioner, 3-12 parts of slow-release nutrient carrier, and 0.6-4 parts of additives. The organic matrix activator is made by mixing straw and livestock manure with humic acid after they have been composted with a rapid composting agent; the water-retaining composite material is prepared by biochar-supported modified sodium polyacrylate; and the slow-release nutrient carrier is obtained by coating amino acid compound fertilizer with a starch-polyvinyl alcohol composite film.

2. The soil amendment fertilizer for improving vegetation survival rate in semi-arid regions according to claim 1, characterized in that, The product is prepared by weight from the following raw materials: 30-50 parts of organic matrix activator, 22-30 parts of water-retaining composite material, 5-10 parts of functional microbial agent, 10-20 parts of mineral conditioner, 5-10 parts of slow-release nutrient carrier, and 1-3 parts of auxiliary agent.

3. The soil amendment fertilizer for improving vegetation survival rate in semi-arid regions according to claim 1, characterized in that, The modified sodium polyacrylate is obtained by modifying sodium polyacrylate by gamma ray irradiation.

4. The soil amendment fertilizer for improving vegetation survival rate in semi-arid regions according to claim 1, characterized in that, The functional microbial agent is made by mixing Bacillus subtilis, phosphorus-solubilizing and potassium-solubilizing bacteria, and nitrogen-fixing bacteria screened locally in semi-arid regions.

5. The soil amendment fertilizer for improving vegetation survival rate in semi-arid regions according to claim 1, characterized in that, The additives include at least one of sodium lignosulfonate, sodium naphthalenesulfonate formaldehyde condensate, sodium polyacrylate, and sodium carboxymethyl cellulose.

6. A method for preparing a soil amendment fertilizer according to any one of claims 1 to 5 for improving vegetation survival rate in semi-arid regions, characterized in that, Includes the following steps: (1) Mix straw, livestock and poultry manure and rapid composting agent, compost and dry them in sequence, then mix them with humic acid and crush them first to obtain organic matrix activated material; (2) Sodium polyacrylate was modified by γ-ray irradiation and dispersed in water to obtain a modified sodium polyacrylate solution; Biochar and the modified sodium polyacrylate solution were mixed and then subjected to ultrasonication, drying, and second pulverization in sequence to obtain a water-retaining composite material. (3) Prepare a coating solution using corn starch, polyvinyl alcohol, plasticizer and emulsifier, and then coat it with amino acid compound fertilizer to obtain a slow-release nutrient carrier; The organic matrix activator obtained in step (1) and the water-retaining composite material obtained in step (2) are mixed with the mineral conditioner, the slow-release nutrient carrier, and the additives, and stirred to obtain a mixture. (4) Add the functional microbial agent to the mixture obtained in step (3), and carry out fermentation, granulation and drying in sequence to obtain a soil improvement fertilizer for improving the survival rate of vegetation in semi-arid areas.

7. The preparation method according to claim 6, characterized in that, The parameters for the composting in step (1) include: controlling the moisture content of the material to be 60%~65%, the composting temperature to be 50~60℃, and the composting time to be 7~10 days.

8. The preparation method according to claim 6, characterized in that, The parameters for gamma irradiation in step (2) include: the irradiation dose of the gamma irradiation equipment used is 20~30kGy, the irradiation temperature is 25~30℃, and the irradiation time in an air atmosphere is 1~2h.

9. The preparation method according to claim 6, characterized in that, In step (3), the amino acid compound fertilizer is composed of urea, potassium dihydrogen phosphate, amino acid raw powder, EDTA-zinc, boric acid, and magnesium sulfate in a mass ratio of (2~5):(1~3):(0.8~1.2):0.5:0.3:0.

2.

10. The preparation method according to claim 6, characterized in that, The parameters for fermentation in step (4) include: controlling the moisture content of the material to 20-25%, the fermentation temperature to 25-30℃, and the fermentation time to 20-28h.

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