A greening system for rural roofs in rocky desertification areas

Abstract

The invention discloses a greening system for rural roofs in rocky desertification areas, and relates to the technical field of roof greening. The roof greening system of the invention comprises a roof structure layer, a leveling layer is arranged on the roof structure layer, a protective layer, a water-draining and water-retaining layer, a filtering and water-retaining layer, a matrix layer and a vegetation layer are arranged on the leveling layer in sequence; the matrix layer comprises the following raw materials in weight percentage: 20-40% coconut husk, 5-15% sandy loam, 5-15% peat soil, 5-10% sawdust, 1-10% rice husk, 5-10% coal slag, 5-10% perlite, 10-20% organic fertilizer, 5-10% biochar and 1-5% modified straw; the vegetation layer comprises ground cover plants, vines, border plants and vegetable crops. The present invention overcomes the problems of uneven seasonal precipitation distribution in rocky desertification areas, high roof evaporation intensity, water shortage, and hot and humid roof microclimate being unfavorable for plant survival. It can not only improve the roof microclimate and increase precipitation utilization rate, but also increase the survival rate of roof greening plants, and the landscape is quickly formed, which is suitable for promotion in rocky desertification areas.

Description

Technical Field

[0001] The invention relates to the technical field of roof greening, and in particular to a greening system for rural roofs in rocky desertification areas. Background Art

[0002] The Southwest Karst region is one of the three major karst concentrated distribution areas in the world. It has the largest area of ​​bare rock, the most intense karst development, the most serious desertification, and the most fragile ecological environment. The land resources suitable for "production-life-ecology" are extremely limited. Due to the implementation of ecological restoration and protection in rocky desertification areas, on the one hand, due to the current climate status of rocky desertification areas, it is not suitable for high-intensity production activities; on the other hand, due to the long-term high-intensity development and utilization of existing production and living land resources, ecological restoration and protection are urgently needed. From the above analysis, land, as an extremely precious resource, has affected the sustainable development of the region and the utilization of the three life spaces.

[0003] my country attaches great importance to ecological degradation and governance in rocky desertification areas. However, there are a series of problems in rocky desertification areas, such as low water resource utilization efficiency, severe seasonal water shortage, delayed soil ecological function recovery, poor vegetation community stability, and poor ecological restoration sustainability, which have brought many obstacles to the comprehensive governance of rocky desertification areas. Although facing the challenges of the rocky desertification ecological dilemma, the local area has actively taken a series of measures to carry out ecological restoration, which has achieved certain results, but it lacks appropriate ecological restoration and transformation based on the current situation from the ecological comprehensive level, and it is urgent to break the conventional thinking and carry out restoration and transformation of rocky desertification areas based on existing resource endowments. Therefore, in order to improve the environment of rocky desertification areas, promote comprehensive governance of rocky desertification areas, and promote sustainable economic development in rocky desertification areas, it is necessary to organically combine rocky desertification ecological governance with local social and economic sustainable development.

[0004] In recent years, my country has continuously promoted the construction of roof greening and achieved certain results. However, at present, the research on roof greening in my country mainly focuses on urban areas, and some discussions have been conducted on the properties of urban roofs, roof waterproofing, roof drainage, soil preparation, roof microclimate, etc. At the same time, a series of promotion and application have been carried out in various urban areas, achieving good results. Compared with the more precious land resources in cities, urban roof greening, as a form of greening that makes multiple spatial utilizations on the original land use resource attributes and effectively improves the green coverage rate, has the advantages of low investment, land saving, opening up green ecological space, beautifying the environment, activating the landscape, protecting the ecological environment, regulating the climate, purifying the air, shading and absorbing heat, saving water and energy, etc. Similar to the rocky desertification areas where land resources are extremely precious, the roofs in rural areas of this region can draw on the relevant experience of existing urban roofs and try to explore as a practical and effective ecological transformation method. Given that there are few studies on rooftop greening transformation in rural areas, it is therefore important to consider the ecological and climatic characteristics of desertification areas and carry out vegetation restoration in difficult areas with extremely limited land adaptability and scarce water resources, so that it can be used for production, climate regulation and tourism while carrying out ecological governance.

[0005] Compared with urban areas, roofs in rural areas with better natural conditions have suitable temperature and precipitation conditions, as well as easy maintenance and management, and have the advantages of transforming green roofs. However, due to the hot and humid climate, seasonal precipitation and water shortage in rocky desertification rural areas, the low planting and survival rates of growing plants pose severe challenges to rural transformation in rocky desertification areas. First, the annual precipitation in rocky desertification rural areas is relatively abundant, but due to the extremely uneven distribution of precipitation frequency, it is easy to cause seasonal drought and water shortage. Therefore, the existing roof water resource efficient storage and recycling technology can be used for seasonal over-management and intermittent use. Secondly, the microclimate in rural areas of rocky desertification areas is relatively hot and humid. Due to the high intensity of roof evaporation caused by traditional roof materials and structures, the microclimate itself poses severe challenges to plant growth. How to select planting species with high adaptability to the local area is an extremely critical issue. In addition, the area of ​​rocky desertified roofs is relatively limited, and existing research is insufficient, making it difficult to provide substantive guidance and reference for the configuration of rooftop crops in the region to adapt to the production-life-ecological model, especially to make full use of the area to layout different types of crops, so as to create a rooftop greening landscape pattern with a reasonable layout, clear levels, staggered arrangements, rich colors, and scenery in all seasons.

[0006] At present, the inventions and other technical materials that have been disclosed provide several types of roof greening systems or technical solutions. However, the inventions and technologies that have been disclosed still have shortcomings in some aspects, and the technologies are difficult to apply to rural areas in rocky desertification areas. For example, a. Application No. CN103503761A is a soilless roof greening system for Sedum plants, which refers to directly laying a soilless root barrier layer, a soilless greening planting matrix and a soilless lawn blanket on the roof, and then controlling the watering by a computer. The invention has the following problems: the greening plants in the soilless greening system are only Sedum plants, and the greening varieties are single. The survival rate is low and the landscape is slow when applied to rocky desertification areas; the technology cannot be used for the next round of plant cultivation and cannot be recycled. b. Application No. CN 101608491 B is a roof greening system and greening method, including a roof greening system with a structural layer, a drainage layer, a filtration and water retention layer, a planting layer, and a vegetation layer. The invention has the following problems: 1. The invention does not briefly describe the roof irrigation method and plant configuration; 2. The roof greening system lacks specificity and it is impossible to determine whether it is suitable for areas where desertification is being promoted.

[0007] As a sustainable technology integrating greening and production, the rural roof greening system in rocky desertification areas is a method specifically for roof greening in rocky desertification areas. Through the application and promotion of the integrated configuration of the benefits of each level of the roof greening system, it is conducive to the regional development of the rocky desertification roof greening system, effectively solving the problem of low local productivity and promoting the formation of cluster effects in rocky desertification areas. This technology effectively alleviates the problems of limited land resources, scarce water resources, and scarce vegetation in rocky desertification areas, increases the vegetation coverage rate in rocky desertification areas, improves the environment in rocky desertification areas, and realizes the organic unity of "production, life and ecology". The rural roof greening system in rocky desertification areas is of great significance to promoting the economic development of rocky desertification areas, driving the development of local eco-tourism and other industries, and promoting the pace of agricultural modernization in rocky desertification areas. Summary of the invention

[0008] In view of the above shortcomings, the present invention provides a greening system for rural roofs in rocky desertification areas. The system overcomes the problems of uneven seasonal precipitation distribution, high roof evaporation intensity, water shortage, and hot and humid roof microclimate that is not conducive to plant survival in rocky desertification areas. It can not only improve the roof microclimate and increase the utilization rate of precipitation, but also increase the survival rate of roof greening plants, and quickly form a landscape, which is suitable for promotion in rocky desertification areas. The specific technical solution is as follows:

[0009] A greening system for rural roofs in rocky desertification areas, comprising a roof structure layer, a leveling layer is arranged on the roof structure layer, and a protective layer, a water drainage and storage layer, a filtration and water retention layer, a matrix layer and a vegetation layer are arranged on the leveling layer in sequence;

[0010] The matrix layer comprises the following raw materials in weight percentage: 20-40% coconut husk, 5-15% sandy loam, 5-15% peat soil, 5-10% sawdust, 1-10% rice husk, 5-10% coal slag, 5-10% perlite, 10-20% organic fertilizer, 5-10% biochar and 1-5% modified straw;

[0011] The vegetation layer includes ground cover plants, vines, border plants and vegetable crops.

[0012] Furthermore, the drainage slope of the leveling layer is set at 2-5%.

[0013] Furthermore, the protective layer is mainly composed of APP plastomer-modified asphalt waterproofing membrane and root-penetration-resistant rigid waterproofing material, and the root-penetration-resistant rigid waterproofing material is arranged on the APP plastomer-modified asphalt waterproofing membrane.

[0014] Furthermore, the drainage and water storage layer is mainly paved with drainage boards.

[0015] Furthermore, the filtration and water-retaining layer comprises a three-layer structure of upper, middle and lower layers, wherein the upper and lower layers are geotextiles respectively, the middle layer is a multi-directional geogrid, and the upper, middle and lower layers are fixed by natural overlap, glue, seams and the like.

[0016] Furthermore, the thickness of the matrix layer is 30-40 cm; the particle sizes of the perlite and biochar are both 0.2-0.5 mm.

[0017] Furthermore, the organic fertilizer contains 2-5% of water-retaining functional bacteria; the water-retaining functional bacteria are Bacillus licheniformis and / or Bacillus laterosporus.

[0018] Furthermore, the modified straw preparation method is: firstly crush the crop straw, add 30-40 times the weight of water and heat to boiling, keep boiling for 2-3 hours, separate the solid and liquid to obtain a first solid, put the first solid into an oxalic acid solution with a mass concentration of 0.5-0.8% and heat it to 100-120°C, keep it for 1-2 hours, separate the solid and liquid to obtain a second solid, put the second solid into a sodium hydroxide solution with a mass concentration of 1-4% and heat it to 50-90°C, keep it for 2-4 hours, separate the solid and liquid to obtain a third solid, add the third solid to sodium chloroacetate for reaction, the reaction temperature is 40-70°C, after reacting for 1-3 hours, adjust the pH to neutral, filter, and dry to obtain.

[0019] Furthermore, the layout of the vegetation layer is as follows: the vines are planted on the edge of the roof, the ground cover plants are planted under the vines, the vegetable crops are planted in a large area of ​​the roof, the edging plants are planted around the vegetable crops, and the edging plants are shrubs. Plant combination modes include: mainly vegetable crop planting + ornamental flowering shrubs + ground cover + hanging vines; mainly ground cover + ornamental flowering shrubs + vegetable planting + hanging vines; mainly shrubs + hanging vines; mainly vegetable planting + hanging vines and other combinations.

[0020] Furthermore, an irrigation device is provided in the vegetation layer, a drip irrigation device is provided in the vine planting area, and a sprinkler irrigation device is provided in the vegetable crop planting area.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The roof greening system of the present invention adopts a lightweight matrix layer with large water holding capacity and good ventilation and drainage properties, and is organically combined with a filtering and water-retaining layer composed of multiple structures and a drainage and water-storage layer composed of modular drainage and water-storage boards to form a water resource efficient utilization and recycling system. The system is conducive to improving the roof microclimate, regulating the water resource allocation and hydrological cycle of the local ecosystem. When the rainfall is small, the filtering and water-retaining layer, the matrix layer and other structures in the system can retain water and reduce evaporation. When the rainfall is heavy, the drainage and water-storage layer, the filtering and water-retaining layer, the matrix layer and other structures in the system can achieve drainage and water storage.

[0023] 2. The layout of the vegetation layer of the present invention overcomes the defect that the roof in the rocky desertification area is not conducive to plant growth due to large evaporation and humidity, and makes the roof microclimate more suitable for plant growth. Among them, vines and border plants can reduce the wind speed inside the roof, reduce the effect of ground turbulence and evaporation heat consumption, and ground cover plants can slow down evaporation, maintain the stability of airflow, humidity, air temperature and soil temperature, provide a more favorable growth environment for plants, and improve the survival rate of plants.

[0024] 3. The modified straw in the substrate layer of the present invention has a strong water-retaining property. It is mixed with coconut husk soil, sandy loam, peat soil, wood chips, rice husks, coal slag, perlite, biochar, and organic fertilizer containing water-retaining functional bacteria to form a substrate layer, which effectively improves the water retention of the substrate layer, thereby reducing evaporation, providing a more favorable growth environment for plants, and improving the survival rate of plants.

[0025] 4. The new roof greening system provided by the present invention can not only reduce roof runoff and intercept most of the precipitation when there is abundant rain, but also quickly discharge excess water; when there is little rainfall, the roof greening system can not only effectively utilize the water resources retained in the various structural layers of the roof, but also use the irrigation layer for irrigation. The water holding performance and drought resistance of the roof greening system not only improve the problem of key water resource storage in rocky desertification areas, but also reduce the pressure on water resource supply, effectively alleviating the serious soil erosion and water shortage in rocky desertification areas.

[0026] 5. The present invention provides a rooftop greening system that implements seasonal irrigation mode according to the rainfall climate characteristics of the small rocky desertification area. Seasonal irrigation is to use rainwater directly for irrigation when there is abundant rainfall, and to use rainwater stored in a pool for intermittent irrigation when there is less rainfall. This irrigation mode is conducive to improving the uneven seasonal precipitation and severe seasonal water shortage in rocky desertification areas.

[0027] 6. The present invention provides a roof greening system, which adopts a zoned irrigation mode according to the irrigation layer laid according to the roof planting situation. Zoned irrigation is to implement different irrigation methods according to different areas, and has two irrigation methods: drip irrigation and micro-sprinkler irrigation. The specific implementation method is to adopt drip irrigation in the area with sparse vegetation on the edge of the roof, and adopt micro-sprinkler irrigation in the large area in the middle of the roof. This irrigation mode combines the characteristics of crop ecological water demand to not only save water resources, but also achieve efficient use of water resources.

[0028] 7. The present invention carries out a matching design for roof plants, effectively utilizes the roof space, and scientifically arranges plants in different areas. First, economic plants such as vegetables with economic value are planted in the middle area of ​​the roof. Secondly, vines are planted in the edge area of ​​the roof to increase the green space, and ornamental plants are mixed into these plants, which are both practical and highly ornamental, and can provide a variety of ecosystem services for local people. This form of roof plant planting and matching design is of great significance to increasing the vegetation coverage rate in rocky desertification areas, promoting economic development in rocky desertification areas, improving the environment in rocky desertification areas, and realizing the organic unity of "production, life and ecology".

[0029] 8. The roof greening system provided by the present invention provides a multi-combination model of plants while taking into account the differences of rural roofs in rocky desertification areas. The green roof model of the entire village is arranged as a whole. This cluster model can not only create a roof greening landscape pattern with a reasonable layout, clear levels, staggered arrangements, rich colors, and scenery in all seasons, but also effectively improve the single ecological environment of local vegetation and the local climate, increase the greening area in rocky desertification areas, beautify the landscape, and comprehensively enhance the ecological service function.

[0030] 9. The roof greening system provided by the present invention adopts an integrated configuration according to local conditions, and has multiple advantages such as low energy consumption, fast landscape formation, easy promotion, and integration of greening and production. Compared with other ecological restoration technology models, it is a method to quickly improve the rocky desertification environment and promote sustainable development in rocky desertification areas.

[0031] 10. Through the promotion and application of various integrated configurations and models of roof greening systems, the benefits can be maximized in rocky desertification areas, which is conducive to promoting local construction and economic development, effectively solving the problem of low local productivity, and realizing ecological restoration and the construction of three-life spaces in rocky desertification areas.

[0032] 11. The present invention provides a roof greening system that takes advantage of the structural characteristics of rural roofs in rocky desertification areas, the unique rocky mountain environment, and good climatic conditions, and actively promotes the application and promotion of the roof greening system model, so that it can form a unique landscape model in rocky desertification areas. This model effectively accelerates the rise of local tourism and economic development, improves the living standards in rocky desertification rural areas, promotes the development and construction of rural ecological activities, and realizes the modernization of agriculture in rocky desertification areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments are briefly introduced below.

[0034] Figure 1 This is a schematic diagram of the structure of the rural roof greening system used in rocky desertification areas according to the present invention;

[0035] Figure 2 A schematic diagram of an irrigation system used in a rural roof greening system in a rocky desertification area according to the present invention;

[0036] Figure 3 This is a top view of the rural roof greening system used in rocky desertification areas according to the present invention.

[0037] Description of main reference numerals:

[0038] 1-roof structure layer, 2-leveling layer, 3-protective layer, 4-drainage and water storage layer, 5-filtration and water retention layer, 6-matrix layer, 7-vegetation layer, 8-roof main drainage outlet, 9-ground cover plants, 10-vines, 11-edging plants, 12-vegetable crops, 13-drainage outlet, 14-drip irrigation device, 15-sprinkler irrigation device. DETAILED DESCRIPTION

[0039] The specific embodiments of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0040] Example 1

[0041] The present embodiment provides a greening system for rural roofs in rocky desertification areas, comprising a roof structure layer 1, a leveling layer 2 being provided on the roof structure layer 1, and a protective layer 3, a water drainage layer 4, a filtration and water retention layer 5, a matrix layer 6 and a vegetation layer 7 being provided on the leveling layer 2 in sequence.

[0042] (1) Construction of leveling layer 2: Clean up the garbage and debris on the roof site, divide the construction section according to the specific conditions of the roof, mark the boundary line, measure the drainage board discharge line, set the slope control line or ash cake as required to control the drainage slope to 2%, and apply the leveling layer in time to reduce moisture and water ingress.

[0043] (2) Construction of protective layer 3: First lay APP plastic modified asphalt waterproof membrane on the leveling layer 2, and then lay root penetration resistant rigid waterproof material.

[0044] (3) Installation of drainage and water storage layer 4: Use manual splicing to install modular water storage and drainage boards. Determine the required drainage boards according to the area of ​​the construction area. Install the water storage and drainage boards according to the measurement lines. Adjust the drainage boards according to the measurement lines to ensure that the drainage boards are discharged neatly and the drainage channels form a straight line.

[0045] (4) Installation of the filtration and water-retention layer 5: First, lay a layer of geotextile on the drainage and water-retention plate, then lay the multi-directional geogrid, and finally lay a layer of geotextile. The edges overlap each other by 5 cm and are partially glued and fixed. Natural overlap or seam fixation can also be used to ensure smooth drainage and prevent soil from flowing into it.

[0046] (5) Laying of substrate layer 6: According to weight percentage, 20% coconut bran soil, 5% sandy loam, 15% peat soil, 10% sawdust, 10% rice husk, 5% coal slag, 5% perlite, 20% organic fertilizer, 5% biochar and 5% modified straw are mixed to obtain a substrate, and the substrate is laid on the filtration and water retention layer with a laying thickness of 30 cm;

[0047] The particle size of perlite and biochar is 0.2 mm, and the organic fertilizer contains 2% Bacillus licheniformis;

[0048] The modified straw preparation method is as follows: firstly, the crop straw is crushed, added into 30 times of water by weight, heated to boiling, kept boiling for 2 hours, solid-liquid separation, and a first solid is obtained; the first solid is placed into an oxalic acid solution with a mass concentration of 0.5%, heated to 100°C, kept for 1 hour, solid-liquid separation, and a second solid is obtained; the second solid is placed into a sodium hydroxide solution with a mass concentration of 1%, heated to 50°C, kept for 2 hours, solid-liquid separation, and a third solid is obtained; the third solid is added into sodium chloroacetate for reaction at a reaction temperature of 40°C; after the reaction for 1 hour, the pH is adjusted to neutral, filtered, and dried to obtain the modified straw.

[0049] (6) Planting of the vegetation layer 7: Select corresponding plants and plant and transplant them on the substrate layer 6; the vegetation layer includes ground cover plants, vines, border plants and vegetable crops; the layout of the vegetation layer is as follows: the vines are planted on the edge of the roof, the ground cover plants are planted under the vines, the vegetable crops are planted in a large area of ​​the roof, and the border plants are planted around the vegetable crops, and the border plants are shrubs.

[0050] Plant combination pattern: mainly vegetable crops + embellishment of flowering shrubs + ground cover plants + hanging vines.

[0051] (7) Installation of irrigation devices: Install drip irrigation devices 14 in the vine planting area and sprinkler irrigation devices 15 in the vegetable crop planting area. Figure 2 .

[0052] After planting, pay attention to plant maintenance to prevent plant diseases and pests; loosen the soil and apply fertilizer to ensure soil circulation and utilization; pay attention to extreme weather, and pay attention to soil drainage and water retention to prevent water outlet blockage.

[0053] Example 2

[0054] The present embodiment provides a greening system for rural roofs in rocky desertification areas, comprising a roof structure layer 1, a leveling layer 2 being provided on the roof structure layer 1, and a protective layer 3, a water drainage layer 4, a filtration and water retention layer 5, a matrix layer 6 and a vegetation layer 7 being provided on the leveling layer 2 in sequence.

[0055] (1) Construction of leveling layer 2: Clean up garbage and debris on the roof site, divide the construction section according to the specific conditions of the roof, mark the boundary line, measure the drainage board discharge line, set the slope control line or ash cake as required to control the drainage slope to 5%, and apply the leveling layer in time to reduce moisture and water ingress.

[0056] (2) Construction of protective layer 3: First lay APP plastic modified asphalt waterproof membrane on the leveling layer, and then lay root penetration resistant rigid waterproof material.

[0057] (3) Installation of drainage and water storage layer 4: Use manual splicing to install modular water storage and drainage boards. Determine the required drainage boards according to the area of ​​the construction area. Install the water storage and drainage boards according to the measurement lines. Adjust the drainage boards according to the measurement lines to ensure that the drainage boards are discharged neatly and the drainage channels form a straight line.

[0058] (4) Installation of the filtration and water-retention layer 5: First, lay a layer of geotextile on the drainage and water-retention plate, then lay the multi-directional geogrid, and finally lay a layer of geotextile. The edges should overlap by 10 cm and be fixed with glue locally. Natural overlap or seam fixation can also be used to ensure smooth drainage and prevent soil from flowing into it.

[0059] (5) Laying of substrate layer 6: 40% coconut bran soil, 10% sandy loam, 5% peat soil, 5% sawdust, 1% rice husk, 10% coal slag, 10% perlite, 10% organic fertilizer, 6% biochar and 3% modified straw were mixed to obtain a substrate, and the substrate was laid on the filtration and water retention layer with a laying thickness of 40 cm;

[0060] The particle size of perlite and biochar is 0.5 mm, and the organic fertilizer contains 5% Bacillus laterosporus;

[0061] The preparation method of the modified straw is as follows: firstly, the crop straw is crushed, added into 40 times of water by weight, heated to boiling, kept boiling for 3 hours, solid-liquid separation, and a first solid is obtained; the first solid is placed into an oxalic acid solution with a mass concentration of 0.8%, heated to 120°C, kept for 2 hours, solid-liquid separation, and a second solid is obtained; the second solid is placed into a sodium hydroxide solution with a mass concentration of 4%, heated to 90°C, kept for 4 hours, solid-liquid separation, and a third solid is obtained; the third solid is added into sodium chloroacetate for reaction at a reaction temperature of 70°C; after the reaction for 3 hours, the pH is adjusted to neutral, filtered, and dried to obtain the modified straw.

[0062] (6) Planting of the vegetation layer 7: Select corresponding plants and plant and transplant them on the substrate layer 6; the vegetation layer includes ground cover plants, vines, border plants and vegetable crops; the layout of the vegetation layer is as follows: the vines are planted on the edge of the roof, the ground cover plants are planted under the vines, the vegetable crops are planted in a large area of ​​the roof, and the border plants are planted around the vegetable crops, and the border plants are shrubs.

[0063] Plant combination pattern: mainly ground cover plants + embellishment of flowering shrubs + vegetable planting + hanging vines.

[0064] (7) Installation of irrigation devices: Install drip irrigation devices 14 in the vine planting area and sprinkler irrigation devices 15 in the vegetable crop planting area. Figure 2 .

[0065] After planting, pay attention to plant maintenance to prevent plant diseases and pests; loosen the soil and apply fertilizer to ensure soil circulation and utilization; pay attention to extreme weather, and pay attention to soil drainage and water retention to prevent water outlet blockage.

[0066] Example 3

[0067] The present embodiment provides a greening system for rural roofs in rocky desertification areas, comprising a roof structure layer 1, a leveling layer 2 being provided on the roof structure layer 1, and a protective layer 3, a water drainage layer 4, a filtration and water retention layer 5, a matrix layer 6 and a vegetation layer 7 being provided on the leveling layer 2 in sequence.

[0068] (1) Construction of leveling layer 2: Clean up garbage and debris on the roof site, divide the construction section according to the specific conditions of the roof, mark the boundary line, measure the drainage board discharge line, set the slope control line or ash cake as required to control the drainage slope to 3%, and apply the leveling layer in time to reduce moisture and water ingress.

[0069] (2) Construction of protective layer 3: First lay APP plastic modified asphalt waterproof membrane on the leveling layer 2, and then lay root penetration resistant rigid waterproof material.

[0070] (3) Installation of drainage and water storage layer 4: Use manual splicing to install modular water storage and drainage boards. Determine the required drainage boards according to the area of ​​the construction area. Install the water storage and drainage boards according to the measurement lines. Adjust the drainage boards according to the measurement lines to ensure that the drainage boards are discharged neatly and the drainage channels form a straight line.

[0071] (4) Installation of the filtration and water-retention layer 5: First, lay a layer of geotextile on the drainage and water-retention plate, then lay the multi-directional geogrid, and finally lay a layer of geotextile. The edges overlap each other by 6 cm and are partially glued and fixed. Natural overlap or seam fixation can also be used to ensure smooth drainage and prevent soil from flowing into it.

[0072] (5) Laying of substrate layer 6: According to weight percentage, 30% coconut husk soil, 15% sandy loam, 10% peat soil, 6% wood chips, 3% rice husk, 6% coal slag, 4% perlite, 15% organic fertilizer, 10% biochar and 1% modified straw were mixed to obtain a substrate, and the substrate was laid on the filtration and water retention layer with a laying thickness of 35 cm.

[0073] The particle sizes of perlite and biochar are both 0.3 mm, and the organic fertilizer contains 3% Bacillus licheniformis and 2% Bacillus laterosporus.

[0074] The preparation method of the modified straw is as follows: firstly, the crop straw is crushed, added into 35 times of water by weight, heated to boiling, kept boiling for 2.5 hours, solid-liquid separation is carried out to obtain a first solid, the first solid is placed into an oxalic acid solution with a mass concentration of 0.7%, heated to 110°C, kept for 1.5 hours, solid-liquid separation is carried out to obtain a second solid, the second solid is placed into a sodium hydroxide solution with a mass concentration of 3%, heated to 80°C, kept for 3 hours, solid-liquid separation is carried out to obtain a third solid, the third solid is added into sodium chloroacetate for reaction, the reaction temperature is 50°C, after reacting for 2 hours, the pH is adjusted to neutral, suction filtered, and dried to obtain the modified straw.

[0075] (6) Planting of the vegetation layer 7: Select corresponding plants and plant and transplant them on the substrate layer 6; the vegetation layer includes ground cover plants, vines, border plants and vegetable crops; the layout of the vegetation layer is as follows: the vines are planted on the edge of the roof, the ground cover plants are planted under the vines, the vegetable crops are planted in a large area of ​​the roof, and the border plants are planted around the vegetable crops, and the border plants are shrubs.

[0076] (7) Installation of irrigation devices: Install drip irrigation devices 14 in the vine planting area and sprinkler irrigation devices 15 in the vegetable crop planting area. Figure 2 .

[0077] After planting, pay attention to plant maintenance to prevent plant diseases and pests; loosen the soil and apply fertilizer to ensure soil circulation and utilization; pay attention to extreme weather, and pay attention to soil drainage and water retention to prevent water outlet blockage.

[0078] Comparative Example 1: The substrate layer does not contain modified straw, and the rest is the same as Example 3.

[0079] Comparative Example 2: The particle sizes of perlite and biochar are both 0.05 mm, and the rest are the same as in Example 3.

[0080] Comparative Example 3: The particle sizes of perlite and biochar are both 0.7 mm, and the rest are the same as in Example 3.

[0081] Comparative Example 4: The organic fertilizer does not contain Bacillus licheniformis and Bacillus laterosporus, and the rest is the same as that in Example 3.

[0082] Comparative Example 5: Except for step (6), the rest is the same as Example 3:

[0083] (6) Planting of vegetation layer: Select appropriate plants and plant and transplant them on the substrate layer; the vegetation layer includes ground cover plants and vegetable crops; the layout of the vegetation layer is: ground cover plants are planted on the edge of the roof, and vegetable crops are planted in a large area of ​​the roof.

[0084] Comparative Example 6: Except for step (6), the rest is the same as Example 3:

[0085] (6) Planting of vegetation layer: Select appropriate plants and plant and transplant them on the substrate layer; the vegetation layer includes vines and border crops; the layout of the vegetation layer is: vines are planted on the edge of the roof, and border plants are planted in large areas of the roof.

[0086] After preparing the substrate layers of the above embodiments and comparative examples, the initial moisture content of each group of substrates was measured first, and then the substrates were laid on the roof at a thickness of 35 cm. After being placed for 20 hours, the moisture content of each group was measured again. The percentage of the latter moisture content to the former moisture content was the water retention rate. The corresponding vegetation was planted according to each embodiment and comparative example, and the same management method was provided to calculate the survival rate. The results are shown in Table 1:

[0087] Table 1 Water retention rate and survival rate of each group

[0088] Group Water retention rate (%) Survival rate (%) Example 1 92 95 Example 2 90 92 Example 3 93 96 Comparative Example 1 71 68 Comparative Example 2 79 78 Comparative Example 3 81 80 Comparative Example 4 76 74 Comparative Example 5 86 87 Comparative Example 6 83 85

[0089] The results show that the particle size of modified straw, perlite and biochar, whether the organic fertilizer contains Bacillus licheniformis and Bacillus laterosporus, and the layout of the vegetation layer all have an impact on the water retention rate and survival rate. The layout of the substrate layer and the vegetation layer of the present invention can improve the microclimate of the roof, provide a favorable growth environment for plants, increase the survival rate of plants, and solve the problem that the microclimate of the roof in rocky desertification areas is not conducive to vegetation growth.

[0090] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. The scope of the present invention is intended to be limited by the claims and their equivalents.

Claims

1. A greening system for rural roofs in rocky desertification areas, characterized in that: It comprises a roof structure layer, a leveling layer is arranged on the roof structure layer, and a protective layer, a water drainage and storage layer, a filtering and water retention layer, a matrix layer and a vegetation layer are arranged on the leveling layer in sequence; The matrix layer includes the following raw materials in weight percentage: 20-40% coconut husk, 5-15% sandy loam, 5-15% peat soil, 5-10% sawdust, 1-10% rice husk, 5-10% coal slag, 5-10% perlite, 10-20% organic fertilizer, 5-10% biochar and 1-5% modified straw; The modified straw preparation method comprises the following steps: firstly crushing the crop straw, adding 30-40 times the weight of water, heating to boiling, keeping boiling for 2-3 hours, separating the solid and the liquid, obtaining a first solid, placing the first solid in an oxalic acid solution with a mass concentration of 0.5-0.8%, heating to 100-120° C., keeping for 1-2 hours, separating the solid and the liquid, obtaining a second solid, placing the second solid in a sodium hydroxide solution with a mass concentration of 1-4%, heating to 50-90° C., keeping for 2-4 hours, separating the solid and the liquid, obtaining a third solid, adding the third solid to sodium chloroacetate for reaction at a reaction temperature of 40-70° C., reacting for 1-3 hours, adjusting the pH to neutral, filtering, and drying to obtain the modified straw; The vegetation layer includes ground cover plants, vines, edging plants and vegetable crops; the layout of the vegetation layer is: the vines are planted on the edge of the roof, the ground cover plants are planted under the vines, the vegetable crops are planted in a large area of ​​the roof, and the edging plants are planted around the vegetable crops.

2. A greening system for rural roofs in rocky desertification areas according to claim 1, characterized in that: The drainage slope of the leveling layer is 2-5%.

3. The greening system for rural roofs in rocky desertification areas according to claim 1 is characterized in that: The protective layer is composed of APP plastomer-modified asphalt waterproofing coiled material and root-penetration-resistant rigid waterproofing material, and the root-penetration-resistant rigid waterproofing material is arranged on the APP plastomer-modified asphalt waterproofing coiled material.

4. The greening system for rural roofs in rocky desertification areas according to claim 1 is characterized in that: The drainage and water storage layer is formed by paving drainage boards.

5. The greening system for rural roofs in rocky desertification areas according to claim 1 is characterized in that: The filtering and water-retaining layer comprises an upper, middle and lower three-layer structure, wherein the upper and lower layers are geotextiles respectively, the middle layer is a multi-directional geogrid, and the upper, middle and lower three layers are fixed by natural overlap, glue and seam connection.

6. The greening system for rural roofs in rocky desertification areas according to claim 1 is characterized in that: The thickness of the matrix layer is 30-40 cm; the particle sizes of the perlite and biochar are both 0.2-0.5 mm.

7. The greening system for rural roofs in rocky desertification areas according to claim 1 is characterized in that: The organic fertilizer contains water-retaining functional bacteria; the water-retaining functional bacteria are Bacillus licheniformis and / or Bacillus laterosporus.

8. The greening system for rural roofs in rocky desertification areas according to claim 1 is characterized in that: An irrigation device is provided in the vegetation layer, a drip irrigation device is provided in the vine planting area, and a sprinkler irrigation device is provided in the vegetable crop planting area.

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