Method for synergistically treating composite soil erosion by shrub and grass, crust and soil on slope

Abstract

The invention discloses a method for cooperatively treating composite soil erosion through shrub and grass, crust and soil on a slope, and relates to the technical field of water and soil conservation. The method comprises the following steps: firstly, dividing into an abrupt slope region, a medium slope region and a gentle slope region according to the gradient, then arranging engineering measures in a targeted manner, and then constructing a three-layer synergistic structure, namely applying a humic acid-complex microbial inoculant-modified charcoal synergist to improve soil, cultivating moss crust protection, planting shrub and grass combinations according to regions, and cooperating with long-term vegetation and soil dynamic maintenance. Partitioned precise treatment is achieved, corrosion resistance strengthening and soil improvement cooperation are achieved, the erosion modulus of abrupt slope, medium slope and gentle slope areas is greatly reduced, the vegetation coverage rate is increased, the planted economic crops also give consideration to ecological protection and economic benefits, and the method is suitable for slope composite erosion treatment.

Description

Technical Field

[0001] This invention relates to the field of soil and water conservation and ecological restoration technology, and more specifically to a method for the synergistic management of complex soil erosion by shrubs, grass, crusting, and soil on slopes, applicable to the ecological management and soil quality improvement of slopes in areas subject to water erosion, wind erosion, and combined wind-water erosion. Background Technology

[0002] Slope soil erosion is a global ecological and environmental problem, especially in areas such as the Loess Plateau where water and wind erosion intersect. Due to the complex terrain, arid climate, and low vegetation cover, soil erosion exhibits a combination of water and wind erosion characteristics, leading to soil degradation, reduced land productivity, and seriously restricting regional ecological security and sustainable agricultural development.

[0003] Existing slope management technologies mostly employ single measures, such as engineering measures (terracing, ridges), vegetation measures (shrub and grass planting), and chemical measures (spraying consolidation materials), which have the following shortcomings: 1) Lack of synergistic design of shrubs, grasses, crusts, and soil, resulting in fragmented management effects that are difficult to maintain in the long term; 2) Disconnection between soil improvement and erosion control, focusing only on erosion control while neglecting the improvement of soil fertility and microbial activity, leading to poor vegetation restoration stability; 3) Low level of intelligence, unable to adjust management measures according to environmental dynamics (such as soil moisture and wind speed), resulting in weak ability to cope with extreme weather; 4) Imbalance between ecological and economic benefits, with long management cycles and slow returns, making it difficult to motivate farmers to participate.

[0004] Therefore, there is an urgent need to develop a composite soil erosion control technology that combines multiple measures, intelligent regulation, and achieves a win-win situation for both ecology and economy, in order to address the shortcomings of existing technologies and realize long-term prevention and control of slope erosion and continuous improvement of soil quality. Summary of the Invention

[0005] In view of this, the present invention provides a method for the synergistic management of complex soil erosion by shrubs, grasses, crusts, and soil on slopes. The core of this method is to construct a three-layer synergistic structure consisting of a "three-dimensional configuration layer of shrubs and grasses, a biological crust protection layer, and a soil improvement synergistic layer". Combined with zoned precise management, engineering assistance, and intelligent regulation, this method achieves full-cycle and all-round management of complex soil erosion.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for the synergistic management of complex soil erosion through shrubs, grasses, crusting, and soil on slopes includes the following steps:

[0008] Step 1: Slope Division

[0009] Based on the slope, the slope is divided into steep slope areas (>50°), medium slope areas (20°~50°), and gentle slope areas (<20°).

[0010] Step Two: Engineering Assistance

[0011] Based on the zoning characteristics of step one, deploy appropriate engineering measures in different areas;

[0012] Step 3: Constructing a Three-Layer Collaborative Structure

[0013] (3.1) Soil improvement: Apply humic acid-compound microbial agent-modified biochar synergist to the slope soil, wherein the mass ratio of humic acid, compound microbial agent and modified biochar in the synergist is 3:1:6~8;

[0014] (3.2) Preparation of biological protective layer: Moss skin is prepared, wherein the moss skin is formed by the composite cultivation of moss spores and sodium carboxymethyl cellulose;

[0015] (3.3) Three-dimensional configuration of shrubs and grasses: Based on the zoning characteristics of step one, different plant combinations are planted in different areas and different moss bark transplantation methods are set;

[0016] Step 4: Long-term maintenance

[0017] Regularly monitor vegetation growth and soil physicochemical properties in each zone, and replant and supplement synergists as needed.

[0018] Preferably, the engineering measures described in step two are as follows:

[0019] Steep slope areas: Spray GJ-1 type consolidation material on the slope surface. Mix the consolidation material with water at a volume ratio of 1:90~100 and spray to a thickness of 2~3mm. If the rainfall is >5mm, re-spray within 24 hours after the rain.

[0020] In the middle slope area: excavate crescent-shaped fish-scale pits with a diameter of 35-40cm and a depth of 25-30cm, arranged in a triangular pattern, with a spacing of 3m×2m between the pits; spray the slope surface with GJZS-2 type consolidation vegetation material, with a volume ratio of consolidation vegetation material to water of 1:140-150, and a dosage of 10-12L / m. 2 Reapply every 3 months;

[0021] No further treatment will be given to gentle slope areas;

[0022] The GJ-1 type consolidation material comprises the following components by weight percentage: 40-45% silicate cement, 8-10% styrene-butadiene latex, 3-5% nano-SiO2, 5-8% bentonite, 0.3-0.5% polyacrylamide, 1-2% quick-setting agent, 0.5-1% water-reducing agent, 1-2% wood fiber, and water as the balance.

[0023] The GJZS-2 type consolidated vegetation material comprises the following components by weight percentage: 25-30% silicate cement, 5-8% cellulose derivative, 10-15% humic acid, 8-10% slow-release fertilizer with N:P2O5:K2O=15:15:15, 1-1.5% potassium polyacrylate, 5-8% vermiculite, 3-5% wood fiber, and water as the remainder.

[0024] Preferably, the humic acid mentioned in step (3.1) is industrial grade, with a humic acid content ≥85%, a pH value of 5.5~7.0, and a water solubility ≥90%; the compound microbial agent contains Bacillus subtilis, phosphate-solubilizing bacteria, and nitrogen-fixing bacteria, and the mass ratio of the three is 2:1:1, with an effective viable count ≥2×10⁻⁶. 9 CFU / g.

[0025] Preferably, the method for preparing the modified biochar in step (3.1) is as follows:

[0026] Corn stalks are crushed to a particle size of 2-5 mm, dried at 105℃ until the moisture content is <10%, and then calcined at a constant temperature of 450-550℃ in an oxygen-free environment for 3-5 hours. After cooling, they are mixed with 5%-8% by mass of nano-silica sol at a solid-liquid ratio of 1:3, stirred and modified at 60-80℃ for 2-3 hours, and then dried at 70-80℃ until the moisture content is <10%, and crushed to a particle size of 0.5-1 mm.

[0027] Furthermore, the effective component in the nano-silica sol is nano-SiO2, with a particle size of 10-20 nm and a mass percentage of 30%-35%.

[0028] Furthermore, the application method and dosage of the soil amendment synergist in step (3.1) correspond to the zoning in step one, specifically as follows:

[0029] Steep slope areas: Mix with GJ-1 type consolidation material at a mass ratio of 1:5, and spray using a high-pressure spray gun (working pressure 0.3~0.5MPa), at a dosage of 1.5~1.8kg / m². 2 ;

[0030] In medium-slope areas: apply in holes, 10-15cm deep, at a rate of 2-3kg / m². 2 ;

[0031] On gentle slopes: After spreading the fertilizer on the slope, rotary tillage is performed to a depth of 20-25cm, using 3-3.5kg / m². 2 .

[0032] Preferably, the cultivation process of moss crust in step (3.2) is as follows:

[0033] (3.2.1) The moss spores were made by mixing gray moss spores (spore viability ≥90%) and gourd moss spores (spore viability ≥90%) in a mass ratio of 1:1. Both were vernalized at 4℃ for 72h and sterilized with 3% hydrogen peroxide for 8min before use.

[0034] (3.2.2) Prepare an aqueous solution of sodium carboxymethyl cellulose with a mass percentage of 0.3%~0.5%, mix it with the spores treated in (3.2.1) at a mass ratio of 5:1, add 5% of compound bacterial agent by mass, and make a suspension;

[0035] (3.2.3) Using a substrate consisting of a 5cm thick layer of humus black soil as the bottom layer, a 10cm thick layer of thin yellow mud as the middle layer, and a 2cm thick layer of compound microbial agent as the spore planting layer, spray the suspension prepared in step (3.2.2), and then control the temperature at 18~25℃, humidity at 80%~85%, light intensity at 1500~2000 Lux, and light duration at 10h / d, and cultivate for 6~8 weeks until the crust coverage rate is ≥90%;

[0036] (3.2.4) Cut the crust along with the 3-8cm thick substrate into 20cm×20cm squares, ready for transplanting. After transplanting, spray the crust with a 0.5% humic acid solution at a rate of 5-8L / m². 2 .

[0037] Furthermore, the organic matter content of the humus black soil is ≥50%, the moisture content of the dilute yellow mud is 30%~35%, and the composite microbial agent layer is made by mixing the composite microbial agent with the topsoil at a mass ratio of 1:20.

[0038] Preferably, the plant combination for the three-dimensional arrangement of shrubs and grasses in step (3.3) is as follows:

[0039] Steep slope areas: Plant sea buckthorn and Virginia creeper at a spacing of 1.0m, and transplant moss crusts to cover the planting gaps;

[0040] In the middle slope area: plant apricot trees in the fish-scale pits at a density of 1 tree per pit, then sow bermudagra seeds in the planting gaps, and cover the surface of the pits with 5-8cm thick chopped straw after sowing, and transplant moss crust between the fish-scale pits.

[0041] Gentle slope area: Plant jujubes and alfalfa, with jujubes and alfalfa planted in alternating rows along contour lines. The row spacing for jujubes is 3.5m and the plant spacing is 3.0m. Alfalfa is planted between the rows of jujubes. Moss and bark are not transplanted in the gentle slope area.

[0042] Preferably, the specific operational procedures and threshold standards for long-term maintenance in step four are as follows:

[0043] Vegetation maintenance: Inspect once a month and record the vegetation survival rate. If the survival rate is less than 70%, replant seedlings of the same size as the original ones.

[0044] Pruning and management: Prune economic fruit trees 1-2 times a year, retaining ≥70% of healthy branches;

[0045] Soil maintenance: Measure the organic matter content of the 0-30cm soil layer quarterly; if <1.0%, supplement with a synergist at 50wt% of the initial application rate; measure soil microbial activity annually, with a viable count <1×10⁻⁶. 9 CFU / g supplemental compound bacterial agent 50g / m 2 .

[0046] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a method for the synergistic management of complex soil erosion by shrubs, grasses, crusting, and soil on slopes, which has the following beneficial effects:

[0047] First, this invention employs zoned, precise management, customizing differentiated technical solutions to adapt to different slope erosion risks. Steep slopes are reinforced with consolidation materials and the application of sea buckthorn, Virginia creeper, and moss crusts to enhance anti-slip and anti-erosion properties. Medium slopes utilize fish-scale pit rainwater harvesting, apricot, bermudagrass, and crust gap covering to balance water retention and soil stabilization. Gentle slopes benefit from the planting of jujube and alfalfa, achieving a win-win situation for both ecology and economy, thus enhancing the targeted management approach.

[0048] Secondly, this invention employs a three-layer synergistic structure to enhance the synergistic effect of erosion resistance and soil improvement, namely:

[0049] Soil improvement: Humic acid improves soil and retains water, compound microbial agents promote nutrient conversion, and modified biochar retains fertilizer through pores. The combination of these three in proportion forms a synergistic effect of physical water retention, microbial activation, and chemical soil improvement. The rate of increase in soil organic matter is greatly improved compared to a single soil conditioner, the number of viable microorganisms is stabilized at a certain level, and the content of soil aggregates is increased.

[0050] Biocrust protection: The combined cultivation of moss spores and CMC enhances the adhesion of the crust and improves its tolerance to wind speed and rainfall intensity;

[0051] Three-dimensional effect of trees, shrubs and grasses: The combination of trees, shrubs and grasses forms a three-dimensional protection with upper interception, middle cover and lower root fixation, which rapidly increases the vegetation coverage rate and has a significant improvement in erosion resistance compared with single herbaceous cover.

[0052] Furthermore, the technical solution of this invention combines engineering assistance and ecological restoration to improve the stability of the treatment. Specifically, in steep slope areas, GJ-1 type consolidation material is sprayed to quickly solidify the surface layer, and mixed with a synergist for spraying, which improves the initial erosion resistance. In medium slope areas, fish scale pits have high rainwater collection efficiency, which solves the problem of vegetation water shortage during drought. The mulch of chopped straw reduces water evaporation. The synergy between engineering and ecological measures has a significant improvement in the continuous stability of the treatment effect compared to no engineering assistance.

[0053] Furthermore, the technical solution of this invention achieves a win-win effect for both ecology and economy, realizing sustainable governance. Specifically, planting jujubes on gentle slopes, combined with alfalfa for nitrogen fixation and soil improvement, continuously enhances soil fertility, achieving a closed loop of erosion control, soil improvement, and economic benefits. On steep and medium slopes, planting sea buckthorn, apricot, etc., has both ecological protection and economic value, and the governance can increase the per capita annual income of the region.

[0054] In summary, this invention solves the core problems of traditional slope erosion control, such as single measures, poor adaptability, short-term effects, and disconnect between ecology and economy, through an integrated technical system of zone adaptation, engineering assistance, three-layer synergy, and long-term maintenance. Detailed Implementation

[0055] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0056] In the following embodiments, the GJ-1 type consolidation material comprises the following components by weight percentage: 40% silicate cement, 9% styrene-butadiene latex, 4% nano-SiO2, 7% bentonite, 0.4% polyacrylamide, 2% quick-setting agent, 0.5% water-reducing agent, 2% wood fiber, and water balance.

[0057] GJZS-2 type consolidated vegetation material comprises the following components by weight percentage: silicate cement 25%, cellulose derivative 6%, humic acid 13%, slow-release fertilizer with N:P2O5:K2O=15:15:15 9%, potassium polyacrylate 1.2%, vermiculite 6%, wood fiber 4%, and water balance.

[0058] Example 1

[0059] Overview of the test area:

[0060] An eroded slope with a total area of ​​1.5 hm² was selected in the gully region of the Loess Plateau. 2 It is divided into three zones according to slope:

[0061] Steep slope area: slope 55°~70°, area 0.3 hm² 2 The soil contained 0.58% organic matter, 8.2% water content, 42% porosity, and 3.2 × 10⁻⁶ viable microorganisms. 8 CFU / g, vegetation coverage <5%;

[0062] Medium slope area: slope 20°~50°, area 0.6 hm² 2The soil contained 0.65% organic matter, 9.5% water content, 45% porosity, and 4.1 × 10⁻⁶ viable microorganisms. 8 CFU / g, vegetation coverage <8%;

[0063] Gentle slope area: slope 10°~15°, area 0.6 hm² 2 The soil contained 0.72% organic matter, 11.3% water content, 48% porosity, and 5.3 × 10⁻⁶ viable microorganisms. 8 CFU / g, vegetation coverage <10%.

[0064] The experiment will last for 24 months (March 2023 to March 2025), with an average annual rainfall of 580 mm, an average annual wind speed of 2.8 m / s, and a frequency of 4 rainstorms per year.

[0065] Preparation of modified biochar:

[0066] Corn stalks were crushed to a particle size of 5 mm, dried at 105°C until the moisture content was <10%, and then calcined at 500°C in an oxygen-free environment for 4 hours. After cooling, they were mixed with 7% by mass nano-silica sol at a solid-liquid ratio of 1:3, stirred and modified at 70°C for 3 hours, and then dried at 80°C until the moisture content was <10%, and crushed to a particle size of 0.8 mm.

[0067] Using the method described in this invention

[0068] Step 1: Slope Division

[0069] A laser slope meter was used to set up measurement points every 20m along the contour lines. Three measurements were taken and the average value was taken to accurately divide the steep slope area (55°~70°), medium slope area (20°~50°), and gentle slope area (10°~15°), and the boundaries of the zones were marked.

[0070] Step Two: Engineering Assistance

[0071] Steep slope areas: Mix GJ-1 type consolidation material with water at a volume ratio of 1:100, and spray evenly using a high-pressure spray gun (working pressure 0.4MPa) to a thickness of 2.5mm. If rainfall exceeds 5mm, spray again within 24 hours.

[0072] In the middle slope area: excavate crescent-shaped fish-scale pits, each 38cm in diameter and 28cm deep, arranged in a triangular pattern with a spacing of 3m x 2m, for a total of 111 pits (0.6hm²). 2 ); Mix GJZS-2 type consolidated vegetation material with water at a volume ratio of 1:145, and add 11L / m 2 Apply the spray solution and reapply every 3 months.

[0073] Gentle slope area: No additional engineering measures will be implemented.

[0074] Step 3: Constructing a Three-Layer Collaborative Structure

[0075] (3.1) Soil improvement

[0076] Synergistic agent formulation: Humic acid (content 88%, pH 6.2, water solubility 92%): Compound bacterial agent (mass ratio of Bacillus subtilis: phosphate-solubilizing bacteria: nitrogen-fixing bacteria = 2:1:1, viable count 2.5 × 10⁻⁶) 9 CFU / g: Modified biochar (particle size 0.8 mm, porosity 62%) = 3:1:7.

[0077] Steep slope areas: The synergist and GJ-1 type consolidation material are mixed at a mass ratio of 1:5, and applied at a concentration of 1.6 kg / m. 2 Apply high-pressure spray at the correct dosage;

[0078] In the mid-slope area: apply in holes, 12cm deep, at a rate of 2.5kg / m². 2 Mix the dosage evenly with the soil in the pit;

[0079] On gentle slopes: After spreading the fertilizer, use a rotary tiller to till to a depth of 22cm, at a rate of 3.2kg / m². 2 Dosage and dosage;

[0080] (3.2) Preparation and transplantation of biological condyle

[0081] Spore pretreatment: Mix spores of *Gynostemma pentaphyllum* (92% viability) and spores of *Bryophyra yezoensis* (91% viability) at a mass ratio of 1:1, vernalize at 4℃ for 72 hours, disinfect with 3% hydrogen peroxide for 8 minutes, and rinse 3 times with sterile water.

[0082] Suspension preparation: Mix 0.4% CMC aqueous solution with pretreated spores at a mass ratio of 5:1, add 5% compound bacterial agent (mass ratio of Bacillus subtilis: phosphate solubilizer: nitrogen fixative bacteria = 2:1:1), stir at 1500 r / min for 10 min;

[0083] Substrate construction: bottom 5cm humus black soil (52% organic matter) + middle 10cm thin yellow mud (32% moisture content) + top 2cm compound microbial agent layer (compound microbial agent with a mass ratio of Bacillus subtilis: phosphate-solubilizing bacteria: nitrogen-fixing bacteria = 2:1:1, and a mass ratio of microbial agent: topsoil = 1:20).

[0084] Cultivation conditions: temperature 22℃, humidity 82%, light intensity 1800 Lux, light intensity 10h / d, cultivation for 7 weeks, skin coverage rate 93%;

[0085] Transplanting: Cut into 20cm×20cm squares (with 5cm of substrate). Transplant in planting gaps on steep slopes and in fish-scale pits on medium slopes. After transplanting, spray with 6L / m² of 0.5% humic acid solution. 2 .

[0086] (3.3) Three-dimensional configuration of shrubs and grasses

[0087] Steep slope areas: Sea buckthorn (25cm branches, dipped in 500mg / L NAA rooting agent) + Virginia creeper (0.6cm diameter vines), planted at a spacing of 1.0m, with moss bark transplanted between the planting gaps;

[0088] In the middle slope area: plant apricot trees (1-year-old seedlings, 0.9cm in diameter) in the fish-scale pits, 1 tree per pit, and sow bermudagra seeds (germination rate 88%) in the gaps. Cover the pits with 6cm of chopped straw and transplant moss bark between the fish-scale pits.

[0089] Gentle slope area: Jujube (HKY-3 type, ground diameter 1.1cm) + alfalfa (germination rate 90%). Jujube is planted along the contour line (row spacing 3.5m, plant spacing 3.0m, total 111 plants), and alfalfa is planted between the rows (row spacing 40cm). Do not transplant the scab.

[0090] Step 4: Long-term maintenance

[0091] Vegetation maintenance: Monthly inspections were conducted. In the 6th month, the survival rate of sea buckthorn on steep slopes was 85%, and that of Virginia creeper was 88%; the survival rate of wild apricot on medium slopes was 82%, and the coverage rate of bermudagrass was 80%; the survival rate of jujube on gentle slopes was 89%, and the coverage rate of alfalfa was 90%. All of these rates were ≥70%, and no replanting was required.

[0092] In the 18th month, the survival rate of sea buckthorn in the steep slope area was 81%, and 6 more plants were replanted.

[0093] Pruning and management: Prune the branches of jujube and apricot trees once a year in November, retaining 75% of the healthy branches;

[0094] Soil maintenance: Organic matter content at 0-30cm depth was measured in the 6th month: 1.02% in steep slopes, 1.15% in medium slopes, and 1.28% in gentle slopes. No synergistic agent was required.

[0095] Viable microbial count in 12 months: 1.8 × 10⁻⁶ in steep slope area 9 CFU / g, Zhongpo area 2.1×10 9 CFU / g, 2.3×10⁻⁶ in gentle slope areas 9 CFU / g, no need for bacterial supplementation;

[0096] In the 18th month, the organic matter content in the steep slope area was 0.98%, and a synergist was added at a rate of 0.8 kg / m². 2 .

[0097] The monitoring data for 24 months is shown in Table 1:

[0098] Table 1. Monitoring data for 24 months of implementation of Example 1

[0099] Comparative Example 1

[0100] The experiment was conducted concurrently in the same experimental area as Example 1, but the difference was that no soil amendment synergist was used; only humic acid was used.

[0101] That is, in step three (3.1), no compound microbial agent and modified biochar are used, only an equal mass of humic acid (88% content) is applied, and the other steps are the same as in Example 1.

[0102] The monitoring data for 24 months is shown in Table 2:

[0103] Table 2. Monitoring data for Comparative Example 1 over 24 months

[0104] Comparative Example 2

[0105] The experiment was conducted concurrently in the same experimental area as Example 1, but the difference from Example 1 was that no biological skin protective layer was used.

[0106] That is, in step three (3.2), lichen crust is not prepared and transplanted, and the other steps are the same as in Example 1.

[0107] The monitoring data for 24 months is shown in Table 3:

[0108] Table 3. Monitoring data for Comparative Example 2 over 24 months

[0109] Comparative Example 3

[0110] The experiment was conducted concurrently in the same experimental area as Example 1, but the difference from Example 1 was that no engineering support measures were implemented.

[0111] That is, no engineering measures are implemented in step two, and the other steps are the same as in Example 1.

[0112] The monitoring data for 24 months is shown in Table 4:

[0113] Table 4. Monitoring data for Comparative Example 3 over 24 months

[0114] Comparative Example 4

[0115] The experiment was conducted concurrently in the same experimental area as Example 1. The difference between Example 1 and Example 2 was that only shrubs and grasses were planted, no synergist was applied, no bark was transplanted, and no engineering assistance was provided. All other steps were the same as in Example 1.

[0116] The monitoring data for 24 months is shown in Table 5:

[0117] Table 5. Monitoring data for Comparative Example 4 over 24 months

[0118] A comparison of Example 1 and Comparative Examples 1-4 above reveals that:

[0119] Example 1 shows that the erosion modulus reduction in steep, medium, and gentle slope areas all exceeded 93%, which is far higher than that in comparative examples 1-4. This demonstrates that synergistic structural treatment and engineering assistance play a core role in erosion resistance.

[0120] In Example 1, the increase in soil organic matter compared to the initial value was much higher than that in Comparative Examples 1-4, and the number of viable microorganisms was 2.2 to 3.1 times that in Comparative Example 1. This shows that humic acid, compound microbial agents, and modified biochar have a synergistic effect on soil improvement.

[0121] In summary, this invention significantly improves the effectiveness, stability, and sustainability of slope erosion control through multi-technology synergy and precise adaptation, providing a replicable technical solution for erosion areas such as the Loess Plateau.

[0122] The various embodiments and comparative examples described in this specification are presented in a progressive manner. The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for compound soil erosion control of grass-slope surface-crust-soil synergistic management, characterized in that, Comprising the following steps: Step one: slope zoning According to the slope, the slope is divided into > 50° steep slope area, 20°~50° medium slope area and < 20° gentle slope area; Step two: engineering assistance According to the zoning characteristics in step one, suitable engineering measures are arranged in different areas; Step three: three-layer collaborative structure construction (3.1) Soil improvement: Apply humic acid-complex bacteria-modified biochar synergist to the slope soil, and the mass ratio of humic acid, complex bacteria and modified biochar in the synergist is 3:1:6~8; (3.2) Preparation of biological crust protection layer: Prepare moss crust, which is prepared by moss spores and sodium carboxymethyl cellulose; (3.3) Three-dimensional configuration of shrubs and grasses: According to the zoning characteristics in step one, different plant combinations and different moss crust transplanting methods are arranged in different areas; Step four: Long-term maintenance Regularly monitor the growth of vegetation and soil physical and chemical properties in each zone, and timely replant and supplement the synergist.

2. The method for compound soil erosion control of grass-sod-crust-slope surface synergistic management according to claim 1, characterized in that, The engineering measures in step two are: Steep slope area: Spray GJ-1 type consolidation material, mix the consolidation material with water at a volume ratio of 1:90~100, spray at a thickness of 2~3mm, and re-spray within 24h after rainfall when the rainfall is >5mm; Middle slope area: excavate half-moon fish scale pits with diameter of 35-40 cm and depth of 25-30 cm, arrange in triangle shape, interval of fish scale pits is 3 m x 2 m; spray GJZS-2 type consolidation vegetation material on slope surface, volume ratio of consolidation vegetation material to water is 1:140-150, spraying amount is 10-12 L / m 2 , spray once every 3 months; The gentle slope area is not treated separately; The GJ-1 type consolidation material comprises the following components by weight percentage: Portland cement 40~45%, styrene-butadiene latex 8~10%, nano-SiO2 23~5%, bentonite 5~8%, polyacrylamide 0.3~0.5%, accelerator 1~2%, water reducing agent 0.5~1%, wood fiber 1~2%, and the balance of water; The GJZS-2 type consolidated vegetation material comprises the following components by weight percentage: Portland cement 25~30%, cellulose derivative 5~8%, humic acid 10~15%, slow-release fertilizer N:P2O5:K2O=15:15:15 8~10%, polyacrylic acid potassium 1~1.5%, vermiculite 5~8%, wood fiber 3~5%, and the balance of water.

3. The method according to claim 2, wherein the method is characterized in that, The humic acid in step (3.1) is an industrial grade, the humic acid content is greater than or equal to 85%, the pH value is 5.5-7.0, and the water solubility is greater than or equal to 90%; the complex microbial agent comprises bacillus subtilis, phosphorus solubilizing bacteria and nitrogen-fixing bacteria, and the mass ratio of the three is 2:1:1, and the effective viable bacterial count is greater than or equal to 2x10 9 CFU / g.

4. The method for compound soil erosion control of grass-sod- crust-slope surface synergistic management according to claim 1, characterized in that, The preparation method of the modified biochar in step (3.1) is: Grind the corn straw to a particle size of 2~5mm, dry at 105℃ to a moisture content of <10%, heat at 450~550℃ in an oxygen-free environment for 3~5h, mix with 5%~8% nano-silica sol at a solid-liquid ratio of 1:3, stir at 60~80℃ for 2~3h, then dry at 70~80℃ to a moisture content of <10%, and grind to a particle size of 0.5~1mm.

5. The method according to claim 4, wherein the method is characterized in that, The effective ingredient in the nano-silica sol is nano-SiO2, with a particle size of 10~20nm and a mass percentage of 30%~35%.

6. The method for compound soil erosion control of grass-sod- crust-slope surface synergistic management according to claim 2, characterized in that, The application method and amount of the soil improvement synergist in step (3.1) are corresponding to the zoning in step one, specifically: Steep slope area: mixed with GJ-1 type consolidation material according to mass ratio 1:5, sprayed by high pressure spray gun with working pressure 0.3~0.5MPa, dosage 1.5~1.8kg / m 2 ; In the middle slope area: hole application, hole depth 10-15 cm, dosage 2-3 kg / m 2 ; Gentle slope area: after spraying on the slope, rotary tillage is used, rotary depth is 20-25 cm, dosage is 3-3.5 kg / m 2 .

7. The method for compound soil erosion control of grass-sod-crust according to claim 1, characterized in that, The cultivation process of the moss crust in step (3.2) is: (3.2.1) Mix the gray moss spores and the gourd moss spores at a mass ratio of 1:1, and store them after 72h of low-temperature hardening at 4℃ and 8min of 3% hydrogen peroxide disinfection; (3.2.2) 0.3%~0.5% of the carboxymethyl cellulose sodium aqueous solution is prepared, mixed with the spores treated in (3.2.1) at a mass ratio of 5:1, and 5% of the compound microbial agent is added to prepare a suspension; (3.2.3) a combined layer of 5cm thick humus black soil as the bottom layer, 10cm thick thin yellow mud as the middle layer, and 2cm thick compound microbial agent layer as the spore planting layer is used as the substrate, the suspension prepared in step (3.2.2) is sprayed, and then the temperature is controlled at 18~25℃, the humidity is controlled at 80%~85%, the illumination is controlled at 1500~2000Lux, the illumination time is controlled at 10h / d, and the cultivation is carried out for 6~8 weeks until the coverage rate of the moss cover is ≥90%; (3.2.4) The crusts are cut into 20 cm x 20 cm squares together with 3-8 cm thick substrate, and are kept for transplanting. After transplanting, a 0.5% humic acid solution by mass is sprayed on the crusts at a rate of 5-8 L / m 2 .

8. The method according to claim 7, wherein the method is characterized in that, The humus black soil has an organic matter content of ≥50%, the thin yellow mud has a water content of 30%~35%, and the compound microbial agent layer is mixed with the surface soil at a mass ratio of 1:

20.

9. The method according to claim 2, wherein the method is characterized in that, The plant combination arranged in the step (3.3) is specifically: In the steep slope area, Hippophae rhamnoides and Ampelopsis glandulifera are planted with a planting distance of 1.0m, and moss cover is transplanted in the planting gap; In the middle slope area, Prunus armeniaca is planted in the fish scale pit with a planting density of 1 plant / pit, and then Digitaria sanguinalis seeds are scattered in the planting gap, and 5~8cm thick crushed straw is covered on the surface of the pit after scattering, and moss cover is transplanted between the fish scale pits; In the gentle slope area, Ziziphus jujuba and Medicago sativa are planted, wherein Ziziphus jujuba and Medicago sativa are staggered along the contour line to form rows, the row spacing of Ziziphus jujuba is 3.5m, the plant spacing is 3.0m, Medicago sativa is planted between the rows of Ziziphus jujuba, and moss cover is not transplanted in the gentle slope area.

10. The method for compound soil erosion control of grass-sod- crust synergistically governed slope surface according to claim 1, characterized in that, The specific operation process and threshold standard of long-term maintenance in step four are: Vegetation maintenance: monthly inspection, record the survival rate of vegetation, and when the survival rate is <70%, replant seedlings with the same specifications as the original; Pruning management: economic forest and fruit trees are pruned 1~2 times per year, and ≥70% of healthy branches are reserved; Soil maintenance: measure the organic matter content of 0-30 cm soil layer every quarter, if <1.0%, supplement the synergistic agent, the dosage is 50wt% of the initial dosage; measure the soil microbial activity every year, if the viable bacterial count <1×10 9 CFU / g, supplement the complex microbial agent 50g / m 2 .

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