Microbial remediation methods to improve desert steppe soil quality

Abstract

This invention discloses a microbial remediation method for improving the soil quality of desert grasslands. The method involves sowing grass seeds and applying microbial fertilizer to pre-treated plots. The grass seed rate is 1-5 kg ​​per mu (approximately 0.067 hectares), and the fertilizer application rate is 15-45 kg per mu. The sowing row spacing is 35 cm, and the sowing depth is 2-3 cm. The grass seeds, by weight, include 40-60 parts of *Gnaphalium affine*, 5-15 parts of *Alternanthera philoxeroides*, and 30-50 parts of *Isodon japonicus*. The microbial fertilizer includes nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and growth-promoting bacteria, with an organic matter content ≥40% and a pH value of 6.5-7.5. Specifically, the nitrogen-fixing bacteria in the microbial fertilizer are *Rhizobium alfalfa* or *Rhizobium soybean*; the phosphate-solubilizing bacteria are *Pseudomonas fluorescens* or *Pseudomonas putida*; and the growth-promoting bacteria are *Bacillus subtilis* or *Bacillus licheniformis*. The weight ratio of the nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and growth-promoting bacteria is 2:1-1.5:1-1.5. This invention effectively improves the physical, chemical, and microbial properties of soil by applying microbial fertilizers and sowing grass seeds.

Description

Technical Field

[0001] This invention relates to the field of soil remediation technology. More specifically, this invention relates to a microbial remediation method for improving the quality of desert steppe soil. Background Technology

[0002] Grassland ecosystems, as one of the most important terrestrial ecosystems, possess extremely important productive and ecological functions. In recent years, due to the continuous extraction of services from grassland ecosystems by humans, varying degrees of degradation have occurred globally. Therefore, curbing grassland degradation and strengthening the management and ecological restoration of degraded grasslands have become major challenges urgently needing to be addressed worldwide. Under the overarching emphasis on ecological priority and green development, a series of ecological restoration measures, including fencing and fertilization, have provided theoretical references for the ecological restoration of degraded grasslands. Fencing is a natural grassland restoration measure, but it requires a long time; therefore, human restoration measures have become indispensable for accelerating grassland recovery. Among these, reseeding is a commonly used and important measure for the ecological restoration of degraded grasslands. It involves directly reseeding suitable and high-quality grass species while minimizing damage or disturbance to the original vegetation and soil. Fertilization is an ecological restoration measure that directly improves the soil nutrient status of degraded grasslands, rapidly promotes vegetation growth, and alters the interspecific relationships of soil microorganisms and the overall quality of the soil. The restorative and negative effects of fertilization vary depending on the type of fertilizer, the amount applied, the duration of fertilization, and habitat conditions. Traditional agriculture's concentrated application of fertilizers leads to low fertilizer utilization and high costs. Long-term excessive fertilization can cause irreversible and far-reaching effects on plant diversity loss in the short term. However, simply sowing grass seeds is not sufficient for effective soil remediation. Summary of the Invention

[0003] One object of the present invention is to solve at least the above-mentioned problems and to provide at least the advantages that will be described later.

[0004] Another objective of this invention is to provide a method that effectively improves the physical, chemical, and microbial properties of soil by applying microbial fertilizers and sowing grass seeds.

[0005] To achieve these objectives and other advantages according to the present invention, a microbial remediation method for improving the soil quality of desert steppe is provided, comprising the following steps:

[0006] Sow grass seeds and apply microbial fertilizer to the pretreated plots. Sow 1-5 kg ​​of grass seeds per mu and apply 15-45 kg of fertilizer per mu. The row spacing is 35 cm and the sowing depth is 2-3 cm. The grass seeds include 40-60 parts of *Gnaphalium affine*, 5-15 parts of *Saussurea involucrata*, and 30-50 parts of *Isodon japonicus* by weight.

[0007] Microbial fertilizers include nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and growth-promoting bacteria, with an organic matter content ≥40% and a pH value of 6.5~7.5;

[0008] The nitrogen-fixing bacteria in the microbial fertilizer are alfalfa rhizobia or soybean rhizobia; the phosphate-solubilizing bacteria are fluorescein or putridus; and the growth-promoting bacteria are Bacillus subtilis or Bacillus licheniformis. The weight ratio of the nitrogen-fixing bacteria, phosphate-solubilizing bacteria and growth-promoting bacteria is 2:1-1.5:1-1.5.

[0009] Preferably, the seeding rate of the grass and the application rate of the microbial fertilizer are dynamically adjusted according to the soil infertility level and climatic conditions, specifically including:

[0010] For slightly infertile soils with an organic matter content of ≥1.5%, the grass seeding rate is 1~2 kg per mu, and the microbial fertilizer application rate is 15~25 kg per mu.

[0011] For moderately infertile soil with an organic matter content of 1.0% to 1.5%, the grass seed sowing rate is 2 to 3 kg per mu, and the application rate of microbial fertilizer is 25 to 35 kg per mu.

[0012] For severely infertile soils with an organic matter content of ≤1.0%, the grass seed sowing rate is 3-5 kg ​​per mu, and the application rate of microbial fertilizer is 35-45 kg per mu.

[0013] Preferably,

[0014] For slightly infertile soil, the grass seed weight ratio is 40 parts of *Gnaphalium affine*, 10 parts of *Saussurea involucrata*, and 50 parts of *Isodon mongolicum*.

[0015] For moderately infertile soil, the grass seed weight ratio is 50 parts of *Gnaphalium affine*, 10 parts of *Alternanthera philoxeroides*, and 40 parts of *Isodon mongolicum*.

[0016] For severely infertile soils, the grass seed weight ratio is 60 parts of *Gnaphalium affine*, 10 parts of *Alternanthera philoxeroides*, and 30 parts of *Isodon japonicus*.

[0017] Preferably, the application method of the microbial fertilizer is to encapsulate the fertilizer using a composite carrier material, specifically including the following steps:

[0018] Microbial fertilizer encapsulation treatment: nitrogen-fixing bacteria, phosphate-solubilizing bacteria and growth-promoting bacteria are mixed with a composite carrier material, which is composed of humic acid, sodium alginate and biochar in a weight ratio of 3:1:2.

[0019] Preferably, the microbial fertilizer is applied in stages, specifically including the following steps:

[0020] First stage: 7-10 days before sowing, evenly spread 50% of the total amount of microbial fertilizer on the surface of the pre-treated plot, and shallowly till the soil to a depth of 10-15cm. Immediately after tilling, cover with a biodegradable water-retaining film with a light transmittance of 60%-70% for 20-30 days.

[0021] The second stage: At the time of sowing, 30% of the total amount of microbial fertilizer is mixed with the grass seeds and applied simultaneously into the sowing furrow. A mixed isolation layer consisting of straw fragments and microbial fertilizer granules, with a thickness of 2-3 cm, is laid in the furrow. The microbial fertilizer granules account for 20%-30% of the isolation layer.

[0022] The third stage: 30 days after the grass seedlings emerge, the remaining 20% ​​of the microbial fertilizer is mixed with nano clay with a particle size ≤100nm at a weight ratio of 1:0.5, and then sprayed onto the soil around the roots of the plants through high-pressure atomization at a pressure of 0.3~0.5MPa.

[0023] Preferably, the encapsulated microbial fertilizer is coated with a combination of natural polymer materials and nano-clay, specifically including the following steps:

[0024] Nano-clay particles with a particle size ≤100nm are incorporated into the embedding process, and the amount incorporated is 5%~10% of the total mass of the embedding material.

[0025] Preferably, both sowing and fertilization are performed using fertilization devices.

[0026] The fertilization device includes a movable frame and two pairs of discharging mechanisms mounted on the movable frame. The two pairs of discharging mechanisms are used to hold fertilizer and grass seeds. Each discharging mechanism includes: a holding bucket, the lower end of which is connected to a transfer cylinder with a circular vertical cross-section; the lower end of the transfer cylinder is connected to a discharging pipe; a rotatable distributing disc is provided inside the transfer cylinder; a driving cylinder is coaxially mounted inside the distributing disc; the driving cylinder rotates through the transfer cylinder; the driving cylinder has threads; a matching threaded rod is provided inside the driving cylinder; a driving rod is provided at the end of the threaded rod; the diameter of the driving rod is smaller than the diameter of the threaded rod; and a fixing point is provided at the end of the driving rod. The material distribution disc is slidably connected to the drive cylinder. The outer edge of the material distribution disc is recessed to form multiple receiving grooves. Each receiving groove includes an inclined transition portion and a cylindrical portion communicating with the transition portion. The central axis of the cylindrical portion is arranged radially along the material distribution disc. The bottom of the cylindrical portion is connected to the drive cylinder through a threaded hole. A first spring is provided at the bottom of the cylindrical portion. An adjusting disc is provided at the end of the first spring. The adjusting disc is slidably connected to the cylindrical portion. A drive rope is provided on the adjusting disc. The drive rope passes through the threaded hole and is connected to the fixed disc to adjust the position of the adjusting disc through the fixed disc.

[0027] Among them, the lower ends of the four discharge pipes in the two pairs of discharge mechanisms are connected to the guide pipe, and the lower end of the guide pipe is equipped with a trencher. The two distribution discs in each pair of discharge mechanisms are arranged in parallel.

[0028] The drive assembly is used to drive the four dispensing discs to rotate.

[0029] Preferably, the movable support has a first gear at its moving wheel;

[0030] The drive assembly includes two connecting shafts rotatably connected to the movable bracket. The two connecting shafts are correspondingly arranged with two pairs of material discharge mechanisms. The two ends of the connecting shafts are respectively connected to the material distribution plate to drive the material distribution plate to rotate. The connecting shafts are provided with a second gear, which is connected to the first gear through a first chain to drive the connecting shaft to rotate. Each connecting shaft is provided with a third gear, and the two third gears are connected through a second chain to enable the two connecting shafts to rotate simultaneously.

[0031] Preferably, the dispensing trays are in multiple sets, and the size and number of the receiving slots in any two sets of dispensing trays are different;

[0032] The connecting shaft has a hollow structure, and the dispensing disc is provided with a connecting rod. The connecting rod rotates through the transfer cylinder and extends into the connecting shaft. The connecting shaft and the connecting rod are connected by a pin.

[0033] The outer side wall of the transfer cylinder is detachably connected to facilitate the replacement of the dispensing disc.

[0034] Preferably, the adjusting disc is provided with a second spring, and the end of the second spring is provided with a driving disc. The driving disc is slidably connected to the cylindrical part. When the opening of the receiving groove faces upward, the second spring is in a compressed state under the gravity of the driving disc.

[0035] The container is equipped with a stirring component to facilitate the discharge of grass seeds or fertilizer.

[0036] The present invention has at least the following beneficial effects:

[0037] First, this invention, through the application of microbial fertilizer and the sowing of grass seeds, effectively improves the physical, chemical, and microbial properties of the soil, reducing bulk density, increasing porosity, and optimizing soil structure. Available phosphorus content and alkaline nitrogen are significantly increased, nutrient release intensity is enhanced, microbial colonization efficiency is improved, and β-1,4-glucosidase activity is increased, thereby enhancing microbial activity.

[0038] Secondly, this invention significantly improves the organic matter content, nutrient availability, and microbial activity of desert steppe soil through microbial fertilizer encapsulation, phased application, and the synergistic effect of grass seeds and nanomaterials. It is particularly suitable for extremely arid environments and provides an efficient and stable technical solution for desertification control.

[0039] Third, this invention uses natural polymer materials and nano-clay particles for synergistic coating. Under drought conditions, the coating layer locks in the internal moisture of the microbial fertilizer through the adsorption of nano-clay, while slowly releasing live bacteria through gel micropores. This ensures that the effective live bacteria count of the microbial fertilizer is preserved at ≥85% under conditions of 40℃ and soil moisture ≤10%, and the survival time is extended to more than 30 days. In the third stage, the synergistic effect of nano-clay and encapsulated microbial fertilizer forms a soil-microbial fertilizer-nano-clay composite protective layer, which increases the colonization efficiency of the microbial community in the soil around the plant roots by 20%~30%.

[0040] Fourth, this invention adjusts the depth of the receiving trough by setting a drive cylinder, a threaded rod, and an adjusting disc, thereby adjusting the capacity based on the required amount of grass seeds or fertilizer, effectively improving the application range of the fertilization device; it drives the adjusting disc to move by setting a drive rope, and it allows for simultaneous adjustment of the positions of multiple drive discs by setting a drive cylinder, which is convenient and quick; this invention facilitates easy replacement of the distributing discs by setting the connecting rod to the connecting rod, the outer side wall of the transfer cylinder to be detachably connected, and multiple pairs of distributing discs; this invention uses a second spring and a drive disc to push the grass seeds or fertilizer in the receiving trough, which is beneficial for the discharge of grass seeds or fertilizer.

[0041] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the fertilization device according to one of the technical solutions of the present invention;

[0043] Figure 2 This is a schematic diagram of the structure of the material holding bucket according to one of the technical solutions of the present invention;

[0044] Figure 3 for Figure 2 A magnified view of A in the middle. Detailed Implementation

[0045] The present invention will be further described in detail below with reference to embodiments, so that those skilled in the art can implement it based on the description.

[0046] <Example 1>

[0047] A microbial remediation method for improving the soil quality of desert steppe includes the following steps:

[0048] For slightly infertile soils with an organic matter content of ≥1.5%, grass seeds and microbial fertilizers are sown on the pre-treated plots. The grass seed sowing rate is 1 kg per mu, the microbial fertilizer application rate is 15 kg per mu, the sowing row spacing is 35 cm, and the sowing depth is 2-3 cm.

[0049] Microbial fertilizers include nitrogen-fixing bacteria, phosphate-solubilizing bacteria, growth-promoting bacteria, calcium, magnesium, organic matter content ≥40%, and pH value 6.5;

[0050] The nitrogen-fixing bacteria in the microbial fertilizer are alfalfa rhizobia with an effective viable count ≥1×10⁸ CFU / g; the phosphate-solubilizing bacteria are Pseudomonas fluorescens with an effective viable count ≥5×10⁷ CFU / g; and the growth-promoting bacteria are Bacillus subtilis with an effective viable count ≥5×10⁷ CFU / g. The weight ratio of the nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and growth-promoting bacteria is 2:1:1.

[0051] The weight ratio of the grass seeds is 40 parts of *Gnaphalium affine*, 10 parts of *Saussurea involucrata*, and 50 parts of *Isodon mongolicum*.

[0052] The application method of the microbial fertilizer involves encapsulating the fertilizer with a composite carrier material, specifically including the following steps:

[0053] Microbial fertilizer encapsulation treatment: nitrogen-fixing bacteria, phosphate-solubilizing bacteria and growth-promoting bacteria are mixed with a composite carrier material, which is composed of humic acid, sodium alginate and biochar in a weight ratio of 3:1:2. The encapsulated microbial fertilizer particles have a diameter of 0.5 mm and an encapsulation rate of ≥90%.

[0054] The microbial fertilizer is applied in stages, specifically including the following steps:

[0055] First stage: Seven days before sowing, evenly spread 50% of the total amount of microbial fertilizer on the surface of the pre-treated plot and shallowly till the soil to a depth of 10-15cm. Immediately after tilling, cover with a biodegradable water-retaining film with a light transmittance of 60% for 20 days.

[0056] Second stage: At the time of sowing, 30% of the total amount of microbial fertilizer is mixed with grass seeds and applied simultaneously into the sowing furrow. A mixed isolation layer consisting of straw fragments and microbial fertilizer granules, with a thickness of 2-3 cm, is laid in the furrow. The microbial fertilizer granules account for 20% of the isolation layer.

[0057] The third stage: 30 days after the grass seedlings emerge, the remaining 20% ​​of the microbial fertilizer is mixed with nano clay with a particle size ≤100nm at a weight ratio of 1:0.5, and then sprayed onto the soil around the roots of the plants through high-pressure atomization at a pressure of 0.3~0.5MPa.

[0058] The microbial fertilizer has an effective viable bacteria retention rate of ≥85% after encapsulation treatment, and its survival time under drought conditions of 40℃ and soil moisture ≤10% is extended to more than 30 days.

[0059] The microbial fertilizer undergoing the encapsulation treatment is coated with a combination of natural polymer materials and nano-clay, specifically including the following steps:

[0060] Nano-clay particles with a particle size ≤100nm are incorporated into the embedding process, and the amount incorporated is 5% of the total mass of the embedding material;

[0061] The coating layer locks in the moisture inside the microbial fertilizer through the adsorption of nano-clay under drought conditions, while slowly releasing live bacteria through gel micropores. This ensures that the effective live bacteria retention rate of the microbial fertilizer is ≥85% under conditions of 40℃ and soil moisture ≤10%, and the survival time is extended to more than 30 days.

[0062] In the third stage, the synergistic effect of nano-clay and embedded microbial fertilizer forms a soil-microbial fertilizer-nano-clay composite protective layer, which increases the colonization efficiency of microorganisms in the soil around the plant roots by 20%.

[0063] <Example 2>

[0064] A microbial remediation method for improving the soil quality of desert steppe includes the following steps:

[0065] For slightly infertile soil with an organic matter content of ≥1.5%, grass seeds and microbial fertilizers are sown on the pre-treated plots. The grass seed sowing rate is 2 kg per mu, the microbial fertilizer application rate is 25 kg per mu, the sowing row spacing is 35 cm, and the sowing depth is 2-3 cm.

[0066] Microbial fertilizers include nitrogen-fixing bacteria, phosphate-solubilizing bacteria, growth-promoting bacteria, calcium, magnesium, organic matter content ≥40%, and pH value 7.5;

[0067] The nitrogen-fixing bacteria in the microbial fertilizer are soybean rhizobia with an effective viable count ≥1×10⁸ CFU / g; the phosphate-solubilizing bacteria are Pseudomonas putida with an effective viable count ≥5×10⁷ CFU / g; and the growth-promoting bacteria are Bacillus licheniformis with an effective viable count ≥5×10⁷ CFU / g. The weight ratio of the nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and growth-promoting bacteria is 2:1.5:1.5.

[0068] The weight ratio of the grass seeds is 40 parts of *Gnaphalium affine*, 10 parts of *Saussurea involucrata*, and 50 parts of *Isodon mongolicum*.

[0069] The application method of the microbial fertilizer involves encapsulating the fertilizer with a composite carrier material, specifically including the following steps:

[0070] Microbial fertilizer encapsulation treatment: nitrogen-fixing bacteria, phosphate-solubilizing bacteria and growth-promoting bacteria are mixed with a composite carrier material, which is composed of humic acid, sodium alginate and biochar in a weight ratio of 3:1:2. The encapsulated microbial fertilizer particles have a diameter of 1.0 mm and an encapsulation rate of ≥90%.

[0071] The microbial fertilizer is applied in stages, specifically including the following steps:

[0072] First stage: 10 days before sowing, evenly spread 50% of the total amount of microbial fertilizer on the surface of the pre-treated plot, and shallowly till the soil to a depth of 10-15cm. Immediately after tilling, cover with a biodegradable water-retaining film with a light transmittance of 70% for 30 days.

[0073] Second stage: At the time of sowing, 30% of the total amount of microbial fertilizer is mixed with grass seeds and applied simultaneously into the sowing furrow. A mixed isolation layer consisting of straw fragments and microbial fertilizer granules, with a thickness of 2-3 cm, is laid in the furrow. The microbial fertilizer granules account for 30% of the isolation layer.

[0074] The third stage: 30 days after the grass seedlings emerge, the remaining 20% ​​of the microbial fertilizer is mixed with nano clay with a particle size ≤100nm at a weight ratio of 1:0.5, and then sprayed onto the soil around the roots of the plants through high-pressure atomization at a pressure of 0.5MPa.

[0075] The microbial fertilizer has an effective viable bacteria retention rate of ≥85% after encapsulation treatment, and its survival time under drought conditions of 40℃ and soil moisture ≤10% is extended to more than 30 days.

[0076] The microbial fertilizer undergoing the encapsulation treatment is coated with a combination of natural polymer materials and nano-clay, specifically including the following steps:

[0077] Nano-clay particles with a particle size ≤100nm are incorporated into the embedding process, and the amount incorporated is 10% of the total mass of the embedding material;

[0078] The coating layer locks in the moisture inside the microbial fertilizer through the adsorption of nano-clay under drought conditions, while slowly releasing live bacteria through gel micropores. This ensures that the effective live bacteria retention rate of the microbial fertilizer is ≥85% under conditions of 40℃ and soil moisture ≤10%, and the survival time is extended to more than 30 days.

[0079] In the third stage, the synergistic effect of nano-clay and embedded microbial fertilizer forms a soil-microbial fertilizer-nano-clay composite protective layer, which increases the colonization efficiency of microorganisms in the soil around the plant roots by 30%.

[0080] <Example 3>

[0081] A microbial remediation method for improving the soil quality of desert steppe includes the following steps:

[0082] For slightly infertile soil with an organic matter content of ≥1.5%, grass seeds and microbial fertilizers are sown on the pre-treated plots. The grass seed sowing rate is 1.5 kg per mu, the microbial fertilizer application rate is 20 kg per mu, the sowing row spacing is 35 cm, and the sowing depth is 2-3 cm.

[0083] Microbial fertilizers include nitrogen-fixing bacteria, phosphate-solubilizing bacteria, growth-promoting bacteria, calcium, magnesium, organic matter content ≥40%, and pH value 7;

[0084] The nitrogen-fixing bacteria in the microbial fertilizer are *Alfalfa Rhizobium*, with an effective viable count ≥1×10⁸ CFU / g; the phosphate-solubilizing bacteria are *Pseudomonas putida*, with an effective viable count ≥5×10⁷ CFU / g; and the growth-promoting bacteria are *Bacillus licheniformis*, with an effective viable count ≥5×10⁷ CFU / g. The weight ratio of the nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and growth-promoting bacteria is 2:1.2:1.2.

[0085] The weight ratio of the grass seeds is 40 parts of *Gnaphalium affine*, 10 parts of *Saussurea involucrata*, and 50 parts of *Isodon mongolicum*.

[0086] The application method of the microbial fertilizer involves encapsulating the fertilizer with a composite carrier material, specifically including the following steps:

[0087] Microbial fertilizer encapsulation treatment: nitrogen-fixing bacteria, phosphate-solubilizing bacteria and growth-promoting bacteria are mixed with a composite carrier material, which is composed of humic acid, sodium alginate and biochar in a weight ratio of 3:1:2. The encapsulated microbial fertilizer particles have a diameter of 0.7 mm and an encapsulation rate of ≥90%.

[0088] The microbial fertilizer is applied in stages, specifically including the following steps:

[0089] First stage: Eight days before sowing, evenly spread 50% of the total amount of microbial fertilizer on the surface of the pre-treated plot and shallowly till the soil to a depth of 10-15cm. Immediately after tilling, cover with a biodegradable water-retaining film with a light transmittance of 65% for 25 days.

[0090] Second stage: At the time of sowing, 30% of the total amount of microbial fertilizer is mixed with grass seeds and applied simultaneously into the sowing furrow. A mixed isolation layer consisting of straw fragments and microbial fertilizer granules, with a thickness of 2-3 cm, is laid in the furrow. The microbial fertilizer granules account for 25% of the isolation layer.

[0091] The third stage: 30 days after the grass seedlings emerge, the remaining 20% ​​of the microbial fertilizer is mixed with nano clay with a particle size ≤100nm at a weight ratio of 1:0.5, and then sprayed onto the soil around the roots of the plants through high-pressure atomization at a pressure of 0.4MPa.

[0092] The microbial fertilizer has an effective viable bacteria retention rate of ≥85% after encapsulation treatment, and its survival time under drought conditions of 40℃ and soil moisture ≤10% is extended to more than 30 days.

[0093] The microbial fertilizer undergoing the encapsulation treatment is coated with a combination of natural polymer materials and nano-clay, specifically including the following steps:

[0094] Nano-clay particles with a particle size ≤100nm are incorporated into the embedding process, and the amount incorporated is 7% of the total mass of the embedding material;

[0095] The coating layer locks in the moisture inside the microbial fertilizer through the adsorption of nano-clay under drought conditions, while slowly releasing live bacteria through gel micropores. This ensures that the effective live bacteria retention rate of the microbial fertilizer is ≥85% under conditions of 40℃ and soil moisture ≤10%, and the survival time is extended to more than 30 days.

[0096] In the third stage, the synergistic effect of nano-clay and embedded microbial fertilizer forms a soil-microbial fertilizer-nano-clay composite protective layer, which increases the colonization efficiency of the microbial community in the soil around the plant roots by 25%.

[0097] <Example 4>

[0098] Microbial remediation was carried out using the method of Example 3, except that the soil to be remediated was moderately barren soil with an organic matter content of 1.0% to 1.5%, the grass seed sowing rate was 2 kg per mu, the application rate of microbial fertilizer was 25 kg per mu, and the weight ratio of grass seeds was 50 parts of *Gnaphalium affine*, 10 parts of *Alternanthera philoxeroides*, and 40 parts of *Isodon japonicus*. The remaining steps were the same as in Example 3.

[0099] <Example 5>

[0100] Microbial remediation was carried out using the method of Example 3, except that the soil to be remediated was moderately barren soil with an organic matter content of 1.0% to 1.5%, the grass seed sowing rate was 3 kg per mu, the microbial fertilizer application rate was 35 kg per mu, and the weight ratio of grass seeds was 50 parts of *Gnaphalium affine*, 10 parts of *Alternanthera philoxeroides*, and 40 parts of *Isodon japonicus*. The remaining steps were the same as in Example 3.

[0101] <Example 6>

[0102] Microbial remediation was carried out using the method of Example 3, except that the soil to be remediated was moderately infertile soil with an organic matter content of 1.0% to 1.5%, the grass seed sowing rate was 2.5 kg per mu, the application rate of microbial fertilizer was 30 kg per mu, and the weight ratio of grass seeds was 50 parts of *Gnaphalium affine*, 10 parts of *Alternanthera philoxeroides*, and 40 parts of *Isodon japonicus*. The remaining steps were the same as in Example 3.

[0103] <Example 7>

[0104] Microbial remediation was carried out using the method of Example 3, except that: the soil to be remediated was severely barren soil with an organic matter content of ≤1.0%; the grass seed sowing rate was 3 kg per mu; the application rate of microbial fertilizer was 35 kg per mu; and the weight ratio of grass seeds was 60 parts of *Gnaphalium affine*, 10 parts of *Alternanthera philoxeroides*, and 30 parts of *Isodon japonicus*. The remaining steps were the same as in Example 3.

[0105] <Example 8>

[0106] Microbial remediation was carried out using the method of Example 3, except that: the soil to be remediated was severely barren soil with an organic matter content of ≤1.0%; the grass seed sowing rate was 5 kg per mu; the amount of microbial fertilizer applied was 45 kg per mu; and the weight ratio of grass seeds was 60 parts of *Gnaphalium affine*, 10 parts of *Alternanthera philoxeroides*, and 30 parts of *Isodon japonicus*. The remaining steps were the same as in Example 3.

[0107] <Example 9>

[0108] Microbial remediation was carried out using the method of Example 3, except that: the soil to be remediated was severely barren soil with an organic matter content of ≤1.0%; the grass seed sowing rate was 4 kg per mu; the application rate of microbial fertilizer was 40 kg per mu; and the weight ratio of grass seeds was 60 parts of *Gnaphalium affine*, 10 parts of *Alternanthera philoxeroides*, and 30 parts of *Isodon japonicus*. The remaining steps were the same as in Example 3.

[0109] <Comparative Example 1>

[0110] For slightly infertile soils with an organic matter content ≥1.5%, grass seeds were sown into the pre-treated plots at a rate of 1.5 kg per acre, with a row spacing of 35 cm. The application rate of bio-fertilizer was 20 kg per acre, with a sowing depth of 2-3 cm. The grass seeds included 50% *Gnaphalium affine*, 10% *Saussurea involucrata*, and 50% *Isodon japonicus*. The microbial fertilizer was not buried or covered, and it was applied simultaneously with the grass seeds (the microbial fertilizer was applied all at once, without being applied in stages).

[0111] <Comparative Example 2>

[0112] For moderately infertile soils with an organic matter content of 1.0% to 1.5%, grass seeds were sown into the pre-treated plots at a rate of 2.5 kg per mu (approximately 0.067 hectares). The application rate of bio-fertilizer was 30 kg per mu (approximately 0.067 hectares). The sowing row spacing was 35 cm, and the sowing depth was 2 to 3 cm. The grass seeds included 50% *Gnaphalium affine*, 10% *Saussurea involucrata*, and 40% *Isodon japonicus*. The bio-fertilizer was not buried or covered, and it was applied simultaneously with the grass seeds (the bio-fertilizer was applied all at once, without being applied in stages).

[0113] <Comparative Example 3>

[0114] For moderately infertile soil with an organic matter content of 1.0% to 1.5%, grass seeds were sown into the pre-treated plots at a rate of 4 kg per mu (approximately 0.067 hectares). The application rate of bio-fertilizer was 40 kg per mu (approximately 0.067 hectares). The sowing row spacing was 35 cm, and the sowing depth was 2 to 3 cm. The grass seeds included 60 parts of *Gnaphalium affine*, 10 parts of *Alternanthera philoxeroides*, and 30 parts of *Isodon japonicus*. The microbial fertilizer was not buried or covered, and it was applied simultaneously with the grass seeds when sowing (the microbial fertilizer was applied all at once, without being applied in stages).

[0115] In Examples 1-9 and Comparative Examples 1-3, when microbial fertilizer was mixed with grass seeds for sowing, both sowing and fertilization were performed using a fertilization device.

[0116] like Figure 1-3As shown, the fertilization device includes a movable frame (the movable frame includes the frame body and moving wheels), and two pairs of discharging mechanisms mounted on the movable frame (in actual use, if more grass seeds need to be sown simultaneously, the number of discharging mechanisms can be increased to meet the needs of simultaneous sowing of multiple grass seeds). The two pairs of discharging mechanisms are used to hold fertilizer and grass seeds. The discharging mechanism includes: a holding bucket 2, the lower end of which is connected to a transfer cylinder 3 with a circular vertical cross-section. The lower end of the transfer cylinder 3 is connected to a discharging pipe 10 (the discharging pipe 10 is inclined). The transfer cylinder 3 is equipped with a rotatable distribution plate 9 (the thickness of the distribution plate 9 is slightly less than the thickness of the holding hopper 2). A drive cylinder 18 (horizontally positioned) is coaxially mounted inside the distribution plate 9. The drive cylinder 18 rotates through the transfer cylinder 3 and extends out of the transfer cylinder 3 (specifically, a through hole 5 is provided on the transfer cylinder 3, the diameter of which is larger than the diameter of the drive cylinder 18). The drive cylinder 18 has threads, and a matching threaded rod 4 is provided inside the drive cylinder 18. A drive rod 20 is provided at the end of the threaded rod 4. The diameter of the drive rod 20 is... The diameter is smaller than that of the threaded rod 4. The end of the drive rod 20 is provided with a fixed disk 21, which is slidably connected to the drive cylinder 18 (the inner wall of the drive cylinder 18 is provided with a first slide rail, on which a first slider is provided, and the first slider is connected to the fixed disk 21). The outer edge of the distributing disk 9 is recessed (recessed towards the central axis of the distributing disk 9) to form multiple receiving grooves 17 (the multiple receiving grooves 17 are equally spaced). Each receiving groove 17 includes an inclined transition portion and a cylindrical portion communicating with the transition portion. The central axis of the cylindrical part is arranged radially along the distribution plate 9. The bottom of the cylindrical part is connected to the drive cylinder 18 through a thread hole. The bottom of the cylindrical part is provided with a first spring 23. The end of the first spring 23 is provided with an adjusting plate 22. The adjusting plate 22 is slidably connected to the cylindrical part. The adjusting plate 22 is provided with a drive rope 24. The drive rope 24 passes through the thread hole and is connected to the fixed plate 21 so as to adjust the position of the adjusting plate through the fixed plate 21 (fertilizer and grass seeds entering the grass trough will not push the adjusting plate 22 to move).

[0117] Among them, the lower ends of the four discharge pipes 10 in the two pairs of discharge mechanisms are connected to the guide pipe 6. The lower end of the guide pipe 6 is provided with a trench opener. The two distribution discs 9 in each pair of discharge mechanisms are arranged in parallel and the two transfer cylinders 3 are arranged in parallel.

[0118] A drive assembly is used to drive the two distributing discs 9 to rotate. During use, based on the amount of seeds and fertilizer required per hole, the threaded rod 4 is turned, the threaded rod 4 moves, and the drive rope 24 moves to adjust the depth of the receiving trough 17. Fertilizer is placed into one of the holding hoppers 2, and grass seeds (Gynostemma pentaphyllum, Safflower, and Mongolian ice grass) are placed into the remaining holding hoppers 2 respectively. The movable frame 1 moves, driving the two distributing discs 9 to rotate, completing the simultaneous sowing and fertilization. By adopting this technical solution, the present invention adjusts the depth of the receiving groove 17 by setting up a drive cylinder 18, a threaded rod 4, and an adjusting disc 22, so as to adjust the capacity based on the required amount of grass seeds or fertilizer, effectively improving the application range of the fertilization device; by setting up a drive rope 24 to drive the adjusting disc 22 to move, and by setting up a drive cylinder 18 to simultaneously adjust the position of multiple drive discs 26, which is convenient and quick; by setting up two pairs of discharge mechanisms, the present invention can simultaneously sow and fertilize three kinds of grass seeds and fertilizers, ensuring that each kind of grass seed in each hole is sown in proportion as much as possible, which not only improves the efficiency of fertilization and sowing, but also effectively improves the quality of desert grassland soil.

[0119] In another technical solution, the movable support 1 is provided with a first gear 8 at the movable wheel (the first gear 8 rotates with the rotation of the movable wheel).

[0120] The driving assembly includes two connecting shafts 12 rotatably connected to the movable bracket 1. Each connecting shaft 12 corresponds to one of two pairs of discharging mechanisms. Both ends of each connecting shaft 12 are connected to the distributing disc 9 to drive its rotation. A second gear 14 is mounted on each connecting shaft 12, and the second gear 14 is connected to the first gear 8 via a chain 7 to drive the connecting shaft 12 to rotate. Each connecting shaft 12 also has a third gear, and the two third gears are connected via a second chain to allow both connecting shafts 12 to rotate simultaneously. Using this technical solution, the present invention achieves the rotation of the distributing disc 9 by rotating the moving wheel through the first gear 8, the second gear 14, and the chain 7.

[0121] In another technical solution, the distributing trays 9 are in multiple groups (the number of distributing trays 9 in each group is the same as the number of holding buckets), and the size and number of the receiving slots 17 in any two groups of distributing trays 9 are different, while the number of receiving slots 17 in each group of distributing trays 9 is equal so that fertilizer and grass seeds can be processed simultaneously.

[0122] The connecting shaft 12 has a hollow structure. The dispensing disc 9 is provided with a connecting rod 13. The connecting rod 13 rotates through the transfer cylinder 3 and extends into the connecting shaft 12 (the transfer cylinder 3 is provided with a through hole 5, and the diameter of the connecting rod 13 is slightly smaller than the diameter of the through hole 5). The connecting shaft 12 and the connecting rod 13 are connected by a pin 15 (both the connecting rod 13 and the connecting shaft 12 are provided with corresponding positioning holes, and the pin 15 is inserted into the positioning holes to fix the connecting rod 13).

[0123] The outer sidewall of the transfer cylinder 3 is detachably connected to facilitate the replacement of the distributing disc 9. By employing this technical solution, the present invention achieves convenient replacement of the distributing disc 9 as needed through the detachable connection of the connecting rod 13, the detachable connection of the outer sidewall of the transfer cylinder 3, and multiple pairs of distributing discs 9.

[0124] In another technical solution, a second spring 25 is provided on the adjusting disc 22, and a driving disc 26 is provided at the end of the second spring 25. The driving disc 26 is slidably connected to the cylindrical part. When the opening of the receiving groove 17 faces upward, the second spring 25 is compressed under the gravity of the driving disc 26. When the opening of the receiving groove 17 faces downward, the second spring 25 extends under the gravity of the driving disc 26, driving the grass seeds or fertilizer in the receiving groove 17 to be discharged. Using this technical solution, the present invention, by setting the second spring 25 and the driving disc 26, pushes the grass seeds or fertilizer in the receiving groove 17, which is beneficial for the discharge of grass seeds or fertilizer.

[0125] In another technical solution, the material container 2 is equipped with a stirring component to facilitate the discharge of grass seeds or fertilizer. By adopting this technical solution, the present invention can agitate the materials within the material container 2 by setting up the stirring component, thereby avoiding the problem of fertilizer or grass seeds being compacted and difficult to discharge during use.

[0126] <Experimental Results>

[0127] Soil remediation was performed using the methods described in Examples 3, 6, and 9, and Comparative Examples 1-3. Soil testing was conducted three years after remediation. A control group was established, consisting of three subgroups: Control 1 (slightly infertile soil with organic matter content ≥1.5%), Control 2 (moderately infertile soil with organic matter content 1.0%–1.5%), and Control 3 (moderately infertile soil with organic matter content 1.0%–1.5%). The testing methods were as follows: soil bulk density was determined using the ring sampler method; soil moisture content was determined using the oven-drying method; and... The volume percentage of soil clay was determined using a laser particle size analyzer; soil pH was determined using the potentiometric method; soil organic carbon was determined using the potassium dichromate titration method; total soil nitrogen was determined using the fully automated Kjeldahl nitrogen determination method; total and available phosphorus in soil were determined using the molybdenum-antimony colorimetric method; alkaline nitrogen in soil was determined using the alkaline diffusion absorption method; total soil microbial count was determined using the plate coating method; soil microbial biomass carbon and nitrogen content were determined using the potassium dichromate titration method after treatment with chloroform fumigation-extraction; soil microbial biomass nitrogen was determined using the fully automated Kjeldahl nitrogen determination method; and the activities of two enzymes were determined using an enzyme-linked immunosorbent assay (ELISA) reader.

[0128] 1. Changes in the physical properties of the soil after remediation

[0129] The changes in the physical properties of the soil in control groups 1-3, comparative examples 1-3, example 3, example 6, and example 9 are shown in Table 1.

[0130] Table 1 shows the changes in the physical properties of the soil.

[0131] <![CDATA[Unit weight (g / cm 3 ).]]> Soil moisture content (%) Clay particle volume percentage (%) pH Example 3 1.18±0.02 b 5.85±0.15 c 0.35±0.08 c 8.75±0.01 a Example 6 1.15±0.03 a 6.40±0.20 b 1.00±0.12 b 8.72±0.02 a Example 9 1.12±0.02 a 7.20±0.25 a 1.10±0.18 a 8.68±0.03 b Control group 1 1.37±0.01 a 4.29±0.11 b 2.00±0.00 c 8.72±0.02 a Control group 2 1.34±0.02 bc 3.95±0.15 c 1.20±0.20 d 8.68±0.03 ab Control group 3 1.30±0.03 d 3.62±0.18 d 2.50±0.25 b 8.63±0.04 b Comparative Example 1 1.25±0.01 ab 4.80±0.20 b 0.80±0.15 e 8.70±0.02 a Comparative Example 2 1.23 ± 0.02 bc 4.99 ± 0.36 b 1.20 ± 0.28 b 8.65 ± 0.01 ab Comparative Example 3 1.26 ± 0.00 ab 5.05 ± 0.23 b 1.09 ± 0.30 b 8.59 ± 0.04 b

[0132] Table 1 shows that sowing grass seeds and applying microbial fertilizers effectively improved the physical properties of the soil, reduced the soil bulk density, and increased the soil moisture content.

[0133] 2. Changes in soil chemical properties after remediation

[0134] The changes in the chemical properties of the soil in control groups 1-3, comparative examples 1-3, example 3, example 6, and example 9 are shown in Table 2.

[0135] Table 2 shows the changes in the physical properties of the soil.

[0136] Organic matter (g / kg) Total nitrogen (g / kg) Total phosphorus (g / kg) Alkaline nitrogen (mg / kg) Available phosphorus (mg / kg) Example 3 15.60±0.25 a 0.50±0.01 a 0.55±0.01 a 22.80±0.50 a 2.50±0.05 a Example 6 14.80±0.30 a 0.45±0.01 a 0.58±0.01 a 25.30±0.60 a 3.20±0.08 a Example 9 12.30±0.25 b 0.40±0.01 b 0.54±0.01 b 20.80±0.50 b 2.80±0.07 b Comparative Example 1 11.26±0.22 c 0.39±0.00 c 0.48±0.00 bc 17.47±0.23 c 1.75±0.01 d Comparative Example 2 13.46±0.18 a 0.41±0.00 a 0.50±0.00 a 18.69±0.99 a 2.07±0.07 a Comparative Example 3 11.66±0.22 c 0.33±0.00 c 0.48±0.00 bc 12.47±0.23 c 1.55±0.01 d Control group 1 10.42±0.20 c 0.31±0.00 c 0.37±0.00 c 11.43±0.12 c 1.12±0.01 d Control group 2 11.46±0.18 a 0.32±0.00 a 0.41±0.00 a 12.69±0.99 a 1.77±0.06 a Control group 3 9.80±0.20 d 0.28±0.00 d 0.35±0.00 d 10.50±0.20 d 1.05±0.02 d

[0137] Table 2 shows that sowing grass seeds and applying microbial fertilizers improved soil nutrient content, specifically increasing the content of soil organic matter, total nitrogen, total phosphorus, available nitrogen, and available phosphorus.

[0138] 3. Changes in the properties of soil microorganisms after remediation

[0139] The changes in soil microbial properties in the control group, comparative example 1, and examples 1-3 are shown in Table 3.

[0140] Table 3 shows the changes in soil microbial properties.

[0141] <![CDATA[Total number of microorganisms (10 4 cfu / g)]]> Microbial biomass carbon (mg / kg) Microbial biomass nitrogen (mg / kg) β-1,4-glucosidase (umol / g / h) β-1,4-N-acetylglucosidase + leucine aminopeptidase (umol / g / h) Example 3 5.80±0.20 a 150.80±6.50 a 20.60±0.50 a 15.30±0.60 a 18.50±0.30 a Example 6 6.20±0.25 a 170.30±7.00 a 23.40±0.60 a 16.80±0.70 a 20.10±0.40 a Example 9 5.50±0.18 a 160.20±6.80 a 19.80±0.55 a 14.90±0.65 a 19.30±0.35 a Comparative Example 1 4.10±0.15 b 120.50±5.20 b 15.30±0.30 b 11.20±0.50 b 14.80±0.20 b Comparative Example 2 4.35±0.21 a 145.56±5.25 a 18.85±0.83 a 13.19±0.54 a 17.69±0.09 a Comparative Example 3 3.78±0.20 b 129.46±16.27 b 13.47±0.41 c 12.87±1.28 b 15.64±0.12 b Control group 1 3.05±0.12 c 96.46±3.74 c 11.57±0.12 c 9.07±0.40 c 12.00±0.10 c Control group 2 2.50±0.10 d 80.20±2.80 d 9.80±0.15 d 7.50±0.30 d 10.50±0.10 d Control group 3 2.00±0.08 e 70.50±2.50 e 8.40±0.10 e 6.80±0.25 e 9.20±0.05 e

[0142] Table 3 shows that sowing grass seeds and applying microbial fertilizers increased the number of soil microorganisms, improved soil microbial biomass, and increased the activity of extracellular enzymes representing carbon and nitrogen acquisition.

[0143] In summary, applying 3 kg / mu of grass seeds and 30 kg / mu of fertilizer can significantly improve the quality of desert steppe soil.

[0144] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A microbial remediation method for improving the soil quality of desert steppe, characterized in that, Includes the following steps: Sow grass seeds and apply microbial fertilizer to the pretreated plots. Sow 1-5 kg ​​of grass seeds per mu and apply 15-45 kg of fertilizer per mu. The row spacing is 35 cm and the sowing depth is 2-3 cm. The grass seeds include 40-60 parts of *Gnaphalium affine*, 5-15 parts of *Saussurea involucrata*, and 30-50 parts of *Isodon japonicus* by weight. Microbial fertilizers include nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and growth-promoting bacteria, with an organic matter content ≥40% and a pH value of 6.5~7.5; The nitrogen-fixing bacteria in the microbial fertilizer are alfalfa rhizobia or soybean rhizobia; the phosphate-solubilizing bacteria are fluorescein or putridus; and the growth-promoting bacteria are Bacillus subtilis or Bacillus licheniformis. The weight ratio of the nitrogen-fixing bacteria, phosphate-solubilizing bacteria and growth-promoting bacteria is 2:1-1.5:1-1.

5. The application method of the microbial fertilizer involves encapsulating the fertilizer with a composite carrier material, specifically including the following steps: Microbial fertilizer encapsulation treatment: nitrogen-fixing bacteria, phosphorus-solubilizing bacteria and growth-promoting bacteria are respectively mixed with a composite carrier material, which is composed of humic acid, sodium alginate and biochar in a weight ratio of 3:1:2; The microbial fertilizer is applied in stages, specifically including the following steps: First stage: 7-10 days before sowing, evenly spread 50% of the total amount of microbial fertilizer on the surface of the pre-treated plot, and shallowly till the soil to a depth of 10-15cm. Immediately after tilling, cover with a biodegradable water-retaining film with a light transmittance of 60%-70% for 20-30 days. The second stage: At the time of sowing, 30% of the total amount of microbial fertilizer is mixed with the grass seeds and applied simultaneously into the sowing furrow. A mixed isolation layer consisting of straw fragments and microbial fertilizer granules, with a thickness of 2-3 cm, is laid in the furrow. The microbial fertilizer granules account for 20%-30% of the isolation layer. The third stage: 30 days after the grass seedlings emerge, the remaining 20% ​​of the microbial fertilizer is mixed with nano clay with a particle size ≤100nm at a weight ratio of 1:0.5, and then sprayed onto the soil around the roots of the plants through high-pressure atomization at a pressure of 0.3~0.5MPa. The microbial fertilizer undergoing the encapsulation treatment is coated with a combination of natural polymer materials and nano-clay, specifically including the following steps: Nano-clay particles with a particle size ≤100nm are incorporated into the embedding process, and the amount incorporated is 5%~10% of the total mass of the embedding material.

2. The microbial remediation method for improving desert steppe soil quality as described in claim 1, characterized in that, The sowing rate of the grass seeds and the application rate of the microbial fertilizer are dynamically adjusted according to the soil infertility level and climatic conditions, specifically including: For slightly infertile soils with an organic matter content of ≥1.5%, the grass seeding rate is 1~2 kg per mu, and the microbial fertilizer application rate is 15~25 kg per mu. For moderately infertile soil with an organic matter content of 1.0% to 1.5%, the grass seed sowing rate is 2 to 3 kg per mu, and the application rate of microbial fertilizer is 25 to 35 kg per mu. For severely infertile soils with an organic matter content of ≤1.0%, the grass seed sowing rate is 3-5 kg ​​per mu, and the application rate of microbial fertilizer is 35-45 kg per mu.

3. The microbial remediation method for improving desert steppe soil quality as described in claim 2, characterized in that, For slightly infertile soil, the grass seed weight ratio is 40 parts of *Gnaphalium affine*, 10 parts of *Saussurea involucrata*, and 50 parts of *Isodon mongolicum*. For moderately infertile soil, the grass seed weight ratio is 50 parts of *Gnaphalium affine*, 10 parts of *Alternanthera philoxeroides*, and 40 parts of *Isodon mongolicum*. For severely infertile soils, the grass seed weight ratio is 60 parts of *Gnaphalium affine*, 10 parts of *Alternanthera philoxeroides*, and 30 parts of *Isodon japonicus*.

4. The microbial remediation method for improving desert steppe soil quality as described in claim 1, characterized in that, Both sowing and fertilization are carried out using fertilization devices: The fertilization device includes a movable frame and two pairs of discharging mechanisms mounted on the movable frame. The two pairs of discharging mechanisms are used to hold fertilizer and grass seeds. Each discharging mechanism includes: a holding bucket, the lower end of which is connected to a transfer cylinder with a circular vertical cross-section; the lower end of the transfer cylinder is connected to a discharging pipe; a rotatable distributing disc is provided inside the transfer cylinder; a driving cylinder is coaxially mounted inside the distributing disc; the driving cylinder rotates through the transfer cylinder; the driving cylinder has threads; a matching threaded rod is provided inside the driving cylinder; a driving rod is provided at the end of the threaded rod; the diameter of the driving rod is smaller than the diameter of the threaded rod; and a fixing point is provided at the end of the driving rod. The material distribution disc is slidably connected to the drive cylinder. The outer edge of the material distribution disc is recessed to form multiple receiving grooves. Each receiving groove includes an inclined transition portion and a cylindrical portion communicating with the transition portion. The central axis of the cylindrical portion is arranged radially along the material distribution disc. The bottom of the cylindrical portion is connected to the drive cylinder through a threaded hole. A first spring is provided at the bottom of the cylindrical portion. An adjusting disc is provided at the end of the first spring. The adjusting disc is slidably connected to the cylindrical portion. A drive rope is provided on the adjusting disc. The drive rope passes through the threaded hole and is connected to the fixed disc to adjust the position of the adjusting disc through the fixed disc. Among them, the lower ends of the four discharge pipes in the two pairs of discharge mechanisms are connected to the guide pipe, and the lower end of the guide pipe is equipped with a trencher. The two distribution discs in each pair of discharge mechanisms are arranged in parallel. The drive assembly is used to drive the four dispensing discs to rotate.

5. The microbial remediation method for improving desert steppe soil quality as described in claim 4, characterized in that, The movable support is provided with a first gear at its moving wheel; The drive assembly includes two connecting shafts rotatably connected to the movable bracket. The two connecting shafts are correspondingly arranged with two pairs of material discharge mechanisms. The two ends of the connecting shafts are respectively connected to the material distribution plate to drive the material distribution plate to rotate. The connecting shafts are provided with a second gear, which is connected to the first gear through a first chain to drive the connecting shaft to rotate. Each connecting shaft is provided with a third gear, and the two third gears are connected through a second chain to enable the two connecting shafts to rotate simultaneously.

6. The microbial remediation method for improving desert steppe soil quality as described in claim 5, characterized in that, The material distribution trays are in multiple sets, and the size and number of the receiving slots in any two sets of material distribution trays are different; The connecting shaft has a hollow structure, and the dispensing disc is provided with a connecting rod. The connecting rod rotates through the transfer cylinder and extends into the connecting shaft. The connecting shaft and the connecting rod are connected by a pin. The outer side wall of the transfer cylinder is detachably connected to facilitate the replacement of the dispensing disc.

7. The microbial remediation method for improving desert steppe soil quality as described in claim 4, characterized in that, The adjusting plate is provided with a second spring, and the end of the second spring is provided with a driving plate. The driving plate is slidably connected to the cylindrical part. When the opening of the receiving groove faces upward, the second spring is in a compressed state under the gravity of the driving plate. The container is equipped with a stirring component to facilitate the discharge of grass seeds or fertilizer.

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