Soil improvement and vegetation restoration method for temporary gravel road in alpine desert region

Abstract

The application belongs to the technical field of soil improvement, and relates to a soil improvement and vegetation recovery method for a temporary sand gravel road in an alpine desert area.The method is characterized in that: matured manure, plant straw and the like are made into activated organic matrix, and are compounded with clay, diatomite, a compound microbial agent and the like to form a microbial improvement agent; sodium-based bentonite, potassium polyacrylate and the like are used to prepare gel water-retaining particles.In gullies, the gel water-retaining particles, the microbial improvement agent, the activated organic matrix and a composite material thereof are layered and laid from bottom to top, and finally, soil is covered and shrub branches are covered, and a film-forming agent is used for protection.After seeding of pasture, precision irrigation is implemented.The application realizes multifunctional synergy of water retention, nutrient supply, microbial activation and physical protection, significantly improves soil fertility, water-retaining capacity and vegetation survival rate, has the characteristics of high repair efficiency, long-lasting effect and strong environmental adaptability, and provides a reliable solution for ecological restoration in an alpine desert area.

Description

Technical Field

[0001] This invention belongs to the technical field of soil improvement, and relates to a method for soil improvement and vegetation restoration of temporary gravel roads in high-altitude desert areas. Background Technology

[0002] The ecological environment of high-altitude desert regions is characterized by extreme features such as frigid and arid climate, scarce rainfall and intense evaporation, infertile and structurally poor soil, and sparse natural vegetation. In these areas, the construction of temporary gravel roads often completely destroys the original fragile surface cover, creating strips of bare land that are difficult to restore naturally, exacerbating soil erosion and land degradation. Currently, commonly used techniques for the ecological restoration of such roads often prove ineffective under the extreme conditions of high-altitude desert regions due to their inherent limitations, exhibiting the following problems:

[0003] (1) Although the topsoil covering method can directly introduce the growth substrate, it is costly and limited in source. Moreover, the introduced soil is often difficult to integrate with the local gravel substrate. Under the action of drought, strong wind and freeze-thaw cycle, it is very easy to harden or be lost, and cannot form a stable and long-lasting plant growth layer. It is a surface replacement rather than a fundamental improvement.

[0004] (2) Applying fertilizers or soil conditioners (such as ordinary chemical fertilizers or uncomposted organic fertilizers) can only provide limited nutrients in a short period of time and cannot improve the aggregate structure and water and fertilizer retention capacity of gravelly soils. Under strong evaporation and strong ultraviolet radiation, nutrients volatilize and leach rapidly and may exacerbate soil salinization. They contribute little to the establishment of a healthy soil microbial environment and have poor remediation effects.

[0005] (3) Although the use of traditional water-retaining agents and other single materials can temporarily alleviate water stress, these materials often have problems such as poor weather resistance, rapid decline in water retention performance, and weak bonding with soil particles. Moreover, they are functionally isolated and cannot work in synergy with nutrient supply and microbial systems, making it difficult to cope with multiple stresses such as water, fertilizer, air, and heat in high-altitude desert areas.

[0006] (4) Due to the lack of water and fertilizer environment for seed germination, the germination rate of plant seeding is low. After germination, the seedlings often die due to interruption of subsequent water and nutrient supply, surface wind erosion or drastic temperature changes. The failure rate of plant establishment is high, and the ecological restoration process is slow and extremely unstable.

[0007] In summary, existing methods are often characterized by being "single-minded, superficial, and short-lived." They typically only intervene in one link of the ecological restoration chain, failing to integrate water retention, nutrient supply, microbial community construction, physical structure improvement, and surface protection into a systematic improvement approach. Consequently, they are ill-suited to the harsh and variable natural conditions of high-altitude desert regions, resulting in low cost-effectiveness and poor long-term ecological benefits. Summary of the Invention

[0008] To address the aforementioned problems, this invention provides a method for soil improvement and vegetation restoration of temporary gravel roads in high-altitude desert areas, specifically comprising the following steps:

[0009] Step 1: Mix well-rotted manure (moisture content ≤30%, organic matter ≥45%), plant straw (3-5mm particles), and soybean meal powder in a mass ratio of (50-60):(20-30):(10-15). Stir at 40-50℃ and 100-200rpm for 5-10 minutes. Then add 1-2% of the total mass of the mixture of compound enzyme and 2-4% of organic acid to adjust the moisture content to 35-45%. Continue stirring for 5-10 minutes and ferment at 40-50℃ for 5-7 hours to obtain activated organic substrate.

[0010] Preferably, the decomposed manure is decomposed sheep manure or decomposed cow manure.

[0011] Preferably, the plant straw is one or more of the following: rice straw, corn straw, wheat straw, caragana straw, highland barley straw, crested wheat straw, and sand wormwood straw.

[0012] Preferably, the complex enzyme includes cellulase, lignin peroxidase and protease in a mass ratio of (4-6):(2-4):(2-4).

[0013] Preferably, the organic acid is one or more selected from citric acid, malic acid, tartaric acid, salicylic acid, acetic acid, and lactic acid.

[0014] Step 2: Premix clay (particle size ≤ 0.05 mm), diatomaceous earth and humic acid, then add compound microbial agent and activated organic matrix, stir at 200-300 rpm for 10-15 min, ferment at 25-35℃ and 75-85% RH in the dark for 60-84 h, turning it over once every 12-24 h to obtain microbial improver.

[0015] Preferably, the mass ratio of clay, diatomaceous earth, humic acid, compound microbial agent and activated organic matrix is ​​(30-40):(15-25):(10-20):(2-4):(10-15).

[0016] Most preferably, the compound microbial agent comprises gelatinous Bacillus powder, Bacillus subtilis powder and Bacillus licheniformis powder, in a mass ratio of (1-2):(0.8-1.2):(0.4-0.6).

[0017] Step 3: Mix sodium-based bentonite with water at 50-70℃ and let it stand to expand for 20-25 hours to obtain bentonite gel; mix potassium polyacrylate with sodium alginate and add the bentonite gel at a rate of 18-22% of total mass / min under shear conditions of 2000-3000 rpm, continue shearing for 10-15 minutes to gradually form an interpenetrating network structure, and finally add an ionic crosslinking agent and continue shearing for 5-10 minutes to initiate instantaneous crosslinking of sodium alginate to obtain gel water-retaining particles.

[0018] Preferably, the mass ratio of sodium bentonite, potassium polyacrylate, sodium alginate, ionic crosslinking agent and water is (10-15):(2-4):(1-3):(3-5):100.

[0019] Most preferably, the ionic crosslinking agent is a calcium chloride solution with a mass fraction of 1-3%.

[0020] Step 4: Mix the microbial modifier and gel water-retaining particles at a mass ratio of (3-5):1, stir at 100-150 rpm, add water in 3-4 portions until the water content is 10-20%, and stir for 10-15 minutes after each addition of water to obtain the composite material.

[0021] Step 5: Till and dig trenches on the gravel road to be improved, removing stones with a diameter ≥5cm. The trenches should be 15-20cm deep, 80-120cm wide, and spaced 4-5m apart. Lay 0.5-0.7kg / m² of [material / material] in each trench from bottom to top. 2 Gel-like water-retaining particles, 4-5 kg / m 2 Microbial modifier, 1-2 kg / m 2 Activated organic matrix and 1-2 kg / m 2 The composite material was used, and finally the ditch was filled with the original soil and covered with 1-1.5 kg / m² of it. 2 Shrub branches (5-10cm in length).

[0022] Preferably, the gel water-retaining particles are mixed with the original soil at a mass ratio of 1:(1-2) before being laid; the microbial conditioner is mixed with the original soil at a mass ratio of 3:(1-2) before being laid; the activated organic matrix is ​​mixed with the original soil at a mass ratio of 2:(1-2) before being laid; and 1-2 L / m² is sprayed after the composite material is laid. 2 Film-forming agent.

[0023] Most preferably, the film-forming agent comprises, based on water, 0.1-0.2% xanthan gum and 0.04-0.06% polyvinyl alcohol by mass fraction.

[0024] Step 6: Sow the forage seeds on the improved gravel road at a density of 20-30 g / m². 2Sowing depth is 1.5-2.5cm. Irrigation is carried out after sowing, with an irrigation rate of 7-9L / m². 2 Irrigation should be carried out in 2-3 applications, with each application spaced 1-2 hours apart. This irrigation method allows the water-retaining components in the composite material to become saturated with water, and also allows the nutrients in the activated organic matrix to diffuse around the seeds. Irrigate after sowing when the soil moisture content in the 0-10cm layer is ≤12%, with each irrigation amount being 3-5L / m². 2 The combined effect of shrub branch mulch and film-forming agents significantly reduced the rate of soil surface moisture evaporation.

[0025] Preferably, the forage seeds include one or more of the following: crested wheatgrass, Kentucky bluegrass, alfalfa, ice grass, reed grass, sand wormwood, star grass, and alkali grass.

[0026] The present invention has the following advantages:

[0027] (1) This invention breaks through the limitations of single measures and constructs a highly efficient and synergistic improvement system integrating nutrient activation, microbial community construction, water regulation, and surface protection. This invention scientifically prepares a series of complementary materials: activated organic matrix provides readily available organic nutrients and an acidic initiation environment; microbial modifiers are implanted with specific functional bacterial communities to achieve continuous decomposition of organic matter, nutrient transformation, and biological improvement of soil structure; gel water-retaining particles, with their unique interpenetrating network structure, possess excellent environmental stability and water absorption and slow-release capabilities; finally, the composite material achieves the organic integration of water and bacteria. These materials are precisely deployed in layers from bottom to top within the trenches according to their functions, from deep water retention, mid-layer microbial activity and nutrient supply, to surface seed germination support, forming a fully functional artificial soil profile. This solves the problem of fragmented remediation in traditional methods and achieves comprehensive improvement of soil water, fertilizer, air, heat, and biological processes.

[0028] (2) This invention significantly improves the long-term effectiveness and stability of the remediation effect, successfully resisting the extreme environmental stress in high-altitude desert areas. This invention ensures long-term efficacy from both the material itself and the system structure. The gel water-retaining particles (sodium bentonite-potassium polyacrylate-sodium alginate composite crosslinking) have excellent mechanical strength and weather resistance. Their water retention performance can be maintained for a long time under wet-dry cycles and temperature fluctuations, providing plants with lasting water protection. The composite functional microbial agent not only accelerates the initial improvement, but its metabolic activity can also continuously promote the formation of soil aggregates, realizing the self-maintenance and improvement of fertility. In addition, the synergistic effect of shrub branch mulching and biodegradable film-forming agent constructs a physical protective layer on the soil surface that is windproof, moisture-retaining, and temperature-regulating. The combination of internal and external factors ensures the successful establishment and stable growth of vegetation in harsh environments.

[0029] (3) This invention is well-suited to the special habitat of high-altitude desert regions, achieving efficient adaptation and cost optimization of technical measures. This invention prioritizes the use of locally available organic materials (such as well-rotted cow and sheep manure, and straw from local plants such as Caragana korshinskii / Artemisia argyi) to reduce costs and enhance ecological compatibility. By adding compound enzymes and organic acids, the activation efficiency of organic matter under low-temperature conditions is improved. The selected functional microbial agents have stronger cold resistance and stress resistance characteristics. The precise irrigation system based on soil moisture content maximizes the use of water-retaining materials and greatly improves water use efficiency.

[0030] (4) This invention applies soil improvement measures to a depth of 20-30cm through deep tillage and trenching, thoroughly breaking down the dense layer of gravel roads and creating space for root expansion. The fertile root layer constructed within the trenches guides the plant roots to penetrate deeply, significantly enhancing the plant's resilience. Simultaneously, the mixed sowing of various locally adapted forage grass seeds can rapidly form complex plant communities with different ecological niches, improving ground cover and biodiversity. Rapid and stable vegetation restoration not only stabilizes the soil but also gradually improves the microclimate, creating conditions for the habitat of insects, soil animals, and other organisms, thereby promoting the process from simple vegetation restoration to the self-sustaining of a complex ecosystem. Detailed Implementation

[0031] The technical solutions in the embodiments of the invention are described clearly and completely below. 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Example 1

[0033] The complex enzyme consists of cellulase, lignin peroxidase, and protease in a mass ratio of 5:3:3.

[0034] Compound microbial agent: Bacillus subtilis powder (purchased from Baoding Ruigu Biotechnology Co., Ltd.), Bacillus subtilis powder (purchased from Weifang Yihao Biotechnology Co., Ltd.), and Bacillus licheniformis powder (purchased from Weifang Yihao Biotechnology Co., Ltd.), with a mass ratio of 1.5:1:0.5.

[0035] Film-forming agent: Based on water, it includes 0.15% xanthan gum and 0.05% polyvinyl alcohol by mass.

[0036] Forage seeds: crested wheatgrass, Kentucky bluegrass, sand fern, ice grass, reed grass, sand wormwood, star grass and alkali grass, in a mass ratio of 3:1:1:2:1:2:1:3.

[0037] The specific steps include:

[0038] Step 1: Mix well-rotted cow manure (moisture content 28%, organic matter ≥45%), caragana stalks (3-5mm particles), and soybean meal powder in a mass ratio of 55:25:12. Stir at 45℃ and 150rpm for 8 minutes. Then add 1.5% of the total mass of the mixture of compound enzyme and 3% of citric acid to adjust the moisture content to 40%. Continue stirring for 6 minutes and ferment at 45℃ for 6 hours to obtain activated organic substrate.

[0039] Step 2: The mass ratio of clay, diatomaceous earth, humic acid, compound microbial agent and activated organic matrix is ​​35:20:15:3:13.

[0040] Clay (particle size ≤ 0.05 mm), diatomaceous earth and humic acid are premixed, then compound bacterial agent and activated organic matrix are added, stirred at 250 rpm for 13 min, fermented at 30℃ and 80% RH in the dark for 72 h, and turned over once every 16 h to obtain microbial improver.

[0041] Step 3: The mass ratio of sodium bentonite, potassium polyacrylate, sodium alginate, calcium chloride solution and water is 13:3:2:4:100.

[0042] Sodium-based bentonite was mixed with water at 60°C and allowed to stand for 24 hours to expand, resulting in bentonite gel. Potassium polyacrylate was mixed with sodium alginate and added to the bentonite gel at a rate of 20% of total mass / min under shearing conditions of 2500 rpm. Shearing continued for 12 minutes, and finally, a 2% calcium chloride solution was added. Shearing continued for 6 minutes to obtain water-retaining gel particles.

[0043] Step 4: Mix the microbial modifier and gel water-retaining particles at a mass ratio of 4:1, stir at 120 rpm, add water in 3 portions until the water content reaches 15%, and stir for 12 minutes after each addition of water to obtain the composite material.

[0044] Step 5: Till and dig trenches on the gravel road to be improved, removing stones with a diameter ≥5cm. The trenches should be 20cm deep, 100cm wide, and spaced 4m apart. Lay 0.6kg / m² of [material name missing] within each trench from bottom to top. 2 Gel-like water-retaining particles, 4.5 kg / m 2 Microbial modifier, 1.5 kg / m 2 The activated organic matrix and 1.5 kg / m 2 The composite material was used, and finally the ditch was filled with the original soil and covered with 1.25 kg / m² of it. 2 Shrub branches (6-7cm in length).

[0045] The gel water-retaining granules are mixed with the original soil at a mass ratio of 1:2 before being laid. The microbial conditioner is mixed with the original soil at a mass ratio of 3:2 before being laid. The activated organic matrix is ​​mixed with the original soil at a mass ratio of 2:1 before being laid. After the composite material is laid, spray 1.5L / m². 2 Film-forming agent.

[0046] Step 6: Sow pasture seeds on the improved gravel road at a density of 25 g / m². 2 Sow at a depth of 2cm, and irrigate after sowing at a rate of 8L / m². 2 The irrigation should be carried out in three stages, with each stage spaced 1.5 hours apart. Irrigation should be performed after sowing when the soil moisture content in the 0-10cm layer is ≤12%, with each irrigation at a rate of 4L / m². 2 .

[0047] Experimental Example 1

[0048] 1. Experiment location and time

[0049] The experiment was conducted in a high-altitude, cold desert region of the Qinghai-Tibet Plateau (altitude approximately 4200m, average annual temperature -2.5℃, annual precipitation approximately 200mm), and a temporary gravel road that had been abandoned for one year was selected as the experimental area.

[0050] 2. Experimental Grouping

[0051] The experimental area was divided into two treatment groups, each with three replication plots (each plot being 500m²). 2 ):

[0052] Experimental group: Soil improvement and vegetation restoration were carried out using the method described in Example 1;

[0053] Control group: Traditional topsoil covering method (covering with 10cm of local cultivated soil, applying 50g / m² of 15-15-15 compound fertilizer) 2 (Sow the same type of forage seeds).

[0054] 3. Monitoring Indicators and Methods

[0055] Soil physicochemical properties: Soil samples from the 0-20cm layer were collected before treatment and at 60 and 150 days after treatment to measure soil moisture content, organic matter, pH, total nitrogen, available phosphorus, available potassium, and other indicators.

[0056] Vegetation growth indicators: Seedling emergence rate, vegetation cover, plant height, and aboveground biomass (dry weight) were investigated at 30, 60, 90, and 150 days after sowing.

[0057] Soil microbial activity: Soil respiration rate (CO2 release) and microbial biomass carbon were measured 90 days after treatment.

[0058] Table 1 Changes in soil physicochemical properties

[0059] Before processing 60 days after treatment (experimental group) 60 days after treatment (control group) 150 days after treatment (experimental group) 150 days after treatment (control group) Soil moisture content (%) 5.2 18.7 10.3 16.5 8.9 Organic matter (g / kg) 3.1 12.6 6.8 15.2 7.1 pH 8.5 7.8 8.3 7.6 8.2 Total nitrogen (g / kg) 0.21 0.85 0.42 1.02 0.48 Available phosphorus (mg / kg) 4.3 28.6 12.4 32.1 13.8 Available potassium (mg / kg) 58 245 132 278 140

[0060] Table 2 Comparison of vegetation restoration effects

[0061]

[0062] Table 3 Comparison of soil microbial activity (90 days after treatment)

[0063] experimental group control group <![CDATA[Soil respiration rate (mg CO2 / kg·d)]]> 38.7 16.2 Microbial biomass carbon (mg / kg) 285.6 124.3

[0064] As shown in Tables 1-3, the experimental group showed significantly better results than the control group in all soil indicators at 60 and 150 days after improvement, indicating that the present invention can continuously improve soil structure, increase nutrient content, regulate pH, and create a suitable root zone environment for plant growth. The experimental group also showed significantly higher germination rate, canopy cover, plant height, and biomass than the control group, indicating that the present invention can significantly promote rapid vegetation establishment and stable growth. The significantly enhanced soil microbial activity in the experimental group demonstrates that the microbial amendment constructed in this invention effectively promotes soil biological activity, which is beneficial to nutrient cycling and soil health.

[0065] The present invention provides a method for soil improvement and vegetation restoration of temporary gravel roads in high-altitude desert areas. Through systematic material preparation and layered deployment, it can significantly improve the soil physicochemical properties of gravel roads, enhance water and fertilizer retention capacity, strengthen microbial activity, and ultimately achieve rapid, stable, and long-lasting vegetation restoration. Compared with traditional topsoil covering methods, the present invention shows significant advantages in soil improvement effect, vegetation establishment speed, and long-term ecological stability.

[0066] 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 soil improvement and vegetation restoration for temporary gravel roads in high-altitude desert areas, characterized in that, Includes the following steps: Step 1: Mix and stir well-rotted manure, plant straw, soybean meal powder, compound enzymes and organic acids in a mass ratio of (50-60):(20-30):(10-15):(0.8-2.1):(1.6-4.2), adjust the moisture content, and ferment to obtain activated organic substrate; Step 2: Mix clay, diatomaceous earth, humic acid, compound microbial agent and activated organic matrix in a mass ratio of (30-40):(15-25):(10-20):(2-4):(10-15) and ferment to obtain microbial improver; Step 3: Sodium-based bentonite and water are mixed and expanded, and then mixed and sheared with potassium polyacrylate, sodium alginate and ionic crosslinking agent to obtain gel water-retaining particles; the mass ratio of sodium-based bentonite, potassium polyacrylate, sodium alginate, ionic crosslinking agent and water is (10-15):(2-4):(1-3):(3-5):

100. Step 4: Mix the microbial modifier and the gel water-retaining particles at a mass ratio of (3-5):1, and add water in 3-4 portions until the water content is 10-20% to obtain the composite material; Step 5: Till and dig trenches on the gravel road to be improved, removing stones with a diameter ≥5cm. Till to a depth of 20-30cm, trench depth of 20-30cm, trench width of 80-120cm, and trench spacing of 4-5m. Lay 0.5-0.7kg / m² of soil from bottom to top in the trenches. 2 Gel-like water-retaining particles, 4-5 kg / m 2 Microbial modifier, 1-2 kg / m 2 Activated organic matrix and 1-2kg / m 2 The composite material was used, and finally the ditch was filled with the original soil and covered with 1-1.5 kg / m² of it. 2 shrub branches; Step 6: Sow the forage seeds on the improved gravel road at a density of 20-30 g / m². 2 Sowing depth is 1.5-2.5cm. Irrigation is carried out after sowing, with an irrigation rate of 7-9L / m². 2 Irrigation should be carried out in 2-3 applications, with an interval of 1-2 hours between each application. Irrigation should be carried out when the moisture content of the 0-10cm soil layer is ≤12%, with each application amounting to 3-5L / m³. 2 .

2. The method for soil improvement and vegetation restoration of temporary gravel roads in high-altitude desert areas according to claim 1, characterized in that, The decomposed manure mentioned in step one is decomposed sheep manure or decomposed cow manure.

3. The method for soil improvement and vegetation restoration of temporary gravel roads in high-altitude desert areas according to claim 1, characterized in that, The plant straw mentioned in step one is one or more of the following: rice straw, corn straw, wheat straw, caragana straw, highland barley straw, crested wheat straw, and sand wormwood straw.

4. The method for soil improvement and vegetation restoration of temporary gravel roads in high-altitude desert areas according to claim 1, characterized in that, The complex enzyme mentioned in step one includes cellulase, lignin peroxidase and protease, in a mass ratio of (4-6):(2-4):(2-4).

5. The method for soil improvement and vegetation restoration of temporary gravel roads in high-altitude desert areas according to claim 1, characterized in that, The organic acid mentioned in step one is one or more of citric acid, malic acid, tartaric acid, salicylic acid, acetic acid and lactic acid.

6. The method for soil improvement and vegetation restoration of temporary gravel roads in high-altitude desert areas according to claim 1, characterized in that, The compound microbial agent mentioned in step two includes gelatinous Bacillus powder, Bacillus subtilis powder and Bacillus licheniformis powder, with a mass ratio of (1-2):(0.8-1.2):(0.4-0.6).

7. The method for soil improvement and vegetation restoration of temporary gravel roads in high-altitude desert areas according to claim 1, characterized in that, The ionic crosslinking agent mentioned in step three is a calcium chloride solution with a mass fraction of 1-3%.

8. The method for soil improvement and vegetation restoration of temporary gravel roads in high-altitude desert areas according to claim 1, characterized in that, In step five, the gel water-retaining particles are mixed with the original soil at a mass ratio of 1:(1-2) before being laid; the microbial conditioner is mixed with the original soil at a mass ratio of 3:(1-2) before being laid; the activated organic matrix is ​​mixed with the original soil at a mass ratio of 2:(1-2) before being laid; and 1-2 L / m² is sprayed after the composite material is laid. 2 Film-forming agent.

9. A method for soil improvement and vegetation restoration for temporary gravel roads in high-altitude desert areas according to claim 8, characterized in that, The film-forming agent, based on water, comprises 0.1-0.2% xanthan gum and 0.04-0.06% polyvinyl alcohol by mass.

10. A method for soil improvement and vegetation restoration for temporary gravel roads in high-altitude desert areas according to claim 1, characterized in that, The forage seeds mentioned in step six include one or more of the following: crested wheatgrass, Kentucky bluegrass, alfalfa, ice grass, reed grass, sand wormwood, star grass, and alkali grass.

Images