Method for repairing mountain forest with brown root disease

Abstract

The invention discloses a method for repairing a mountain forest with brown root disease. The method provided by the invention comprises the steps of digging planting holes, transporting original planting soil outwards, disinfecting and sterilizing before planting, laying a root blocking plate, laying a perforated root blocking film, backfilling foreign soil and planting nursery stocks. According to the method, ecological restoration is carried out on the diseased woods in the later stage of brown root disease infection, the woods in the brown root disease infection area can be rapidly restored, repeated infection of the brown root disease is prevented, the disease resistance of the woods is enhanced, and the biological diversity is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of forest and grass ecological restoration, and specifically relates to a method for restoring a mountain forest with brown root root disease. Background Art

[0002] Brown root disease is a tree root disease caused by fungi. Brown root disease bacteria prefer acidic, hot and humid environments. Brown root disease bacteria can release enzymes through micro-hyphae and other tissues, and degrade lignin and polysaccharide components in the cell wall, such as cellulose, hemicellulose and pectin, causing wood decay in trees. Brown root disease has more than 100 host tree species, causing great harm to the healthy growth of forests.

[0003] At present, the main prevention and control measures for brown root disease include cutting down diseased trees, digging trenches to block the spread of pathogens, fumigating diseased soil and planting disease-free seedlings. However, there is no ideal control agent or method that can effectively control the occurrence of brown root disease in trees.

[0004] In addition, there are biological control methods. Biological control is a control method that uses beneficial organisms or other organisms to inhibit or eliminate harmful organisms. It achieves growth promotion and disease prevention through the interaction between plants, pathogens, antagonistic bacteria, plant surface and surrounding microbial communities, and the natural environment. The types of biocontrol microorganisms currently being studied include actinomycetes, Trichoderma, Bacillus, and other major categories. However, biological control research is in its infancy, and work is mainly focused on its isolation, screening, and indoor potted control experiments. The germplasm resources of biocontrol microorganisms for brown root disease need to be further explored and their diversity enriched; moreover, the environmental conditions for field applications are far more complex than those for indoor experiments, so a lot of exploration work is still needed on the biological control of brown root disease.

[0005] With the implementation of the ecological construction of Green Guangdong and the construction of Beautiful China, some forests contaminated by brown root root disease need to undergo ecological restoration in the form of stand transformation. However, since the soil has been polluted, the existing prevention and control methods cannot guarantee that newly planted seedlings will not be infected by the disease during the seedling stage. No better ecological restoration method for dealing with brown root root disease has been proposed in relevant studies, and there is no relevant data to prove the effectiveness of existing prevention and control methods. Summary of the invention

[0006] In response to the current status of brown root disease infection in forests in the Guangdong-Hong Kong-Macao Greater Bay Area, the present invention provides a comprehensive prevention and control method that combines special physical prevention and chemical prevention. On the forest soil contaminated by brown root disease bacteria, a forest stand dominated by native broad-leaved trees was rebuilt, and the forest ecological restoration was carried out. The overall effect is outstanding, and no diseased trees have been found in 2.5 years of afforestation.

[0007] The purpose of the present invention is to provide a method for repairing brown root root diseased mountain forests, comprising the following steps:

[0008] S1. Dig the planting hole 1-2 months before planting the seedlings, and disinfect and sterilize the planting hole and the area 1m around the planting hole;

[0009] S2. A root barrier is laid on the side wall of the planting hole, and a root barrier film is laid at the bottom of the planting hole; the root barrier film is punched with small holes with a spacing of 100mm×100mm and a hole diameter of 80-100mm;

[0010] S3. Mix 1.0-1.5kg of basal fertilizer with a small amount of imported soil and spread it on the bottom of the planting hole, and backfill with imported soil;

[0011] S4. Planting seedlings.

[0012] Preferably, the disinfection and sterilization in step S1 is performed by spraying with a fungicide of appropriate concentration until the soil at a depth of more than 0.5 m is moistened.

[0013] Preferably, after the disinfection and sterilization in step S1, a step of covering with a ground film is also included.

[0014] Preferably, the thickness of the root blocking plate and the root barrier membrane in step S2 is 1.5 mm.

[0015] Preferably, the imported soil in step S3 is loess soil and peat soil mixed in a volume ratio of 3:1.

[0016] Preferably, the base fertilizer in step S3 is organic fertilizer, and calculated by mass percentage, the organic matter content is more than 30%, and the contents of N, P and K are more than 8%.

[0017] Preferably, the step S4 further includes a step of supporting seedlings.

[0018] Beneficial effects of the present invention:

[0019] The present invention has formulated special disinfection and sterilization, root barrier boards and root barrier films, which can effectively prevent brown root pathogenic bacteria from infecting seedlings in a small range, and at the same time minimize the influence of diseased soil on the root growth of seedlings. Compared with the traditional prevention and control methods of simply cutting down diseased trees, digging trenches to block the spread of pathogens, fumigating diseased soil and planting disease-free seedlings, the present invention can significantly improve the ability to utilize natural water diversion while preventing brown root pathogen infection. The growth of seedlings is not affected, and the restoration effect of brown root pathogenic bacteria contaminated areas is significantly improved.

[0020] The traditional prevention and control method of isolating the planting area with plastic sheets is to isolate the planting area from the non-planting area with plastic sheets in the trench, which is a large-scale isolation. Because the traditional method is to isolate the entire planting area, it is necessary to dig out the main roots and fine roots of the trees remaining in the planting area for pollution-free treatment and disinfect the soil, but this treatment method is difficult to completely kill the pathogens. The present invention only needs to use root barriers and root barrier films for isolation of the planting holes. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of disinfection and sterilization before planting seedlings.

[0022] Figure 2 It is a schematic diagram of setting up root barriers and root barrier membranes in planting holes.

[0023] Figure 3 It is a schematic diagram of the hole specifications at the bottom of the root barrier membrane.

[0024] Figure 4 This is a schematic diagram of backfilling soil and applying base fertilizer.

[0025] Figure 5 It is a schematic diagram of planting and supporting seedlings. DETAILED DESCRIPTION

[0026] The following examples are provided to further illustrate the present invention, rather than to limit the present invention.

[0027] The following examples are 55850m 2 The ecological restoration project for forests contaminated by brown root pathogen has produced obvious results. The restoration work lasted from February 2022 to August 2024. No diseased trees were found in the 2.5 years.

[0028] At the beginning of afforestation (February 2022), the stand density was 0.4, the initial specifications of the seedlings were 0.6-0.8cm ground diameter, 0.8-1.0m tree height, and 0.2-0.3m average crown width. In August 2024, the seedling growth indicators, survival rate, and brown root pathogen infection rate were measured. The ground diameter was measured with a vernier caliper, and the tree height and crown width were measured with a tape measure.

[0029] The following embodiments are applicable both on slopes and flat ground.

[0030] Example 1

[0031] This example uses 6 tree species (Table 1), with 10 seedlings of each tree species. Among them, 5 trees of each tree species adopt the technical method of transporting planting soil, disinfecting and sterilizing before planting, laying root barrier boards, laying perforated root barrier membranes, backfilling foreign soil, and planting seedlings, and the other 5 trees adopt the traditional method of digging trenches to block pathogen transmission, disinfecting diseased soil, and planting seedlings. After 30 months of planting, the seedling growth indicators and brown root pathogen infection were tested.

[0032] The specific plan of the technical method of transporting planting soil, disinfecting and sterilizing before planting, laying root barriers, laying perforated root barrier membranes, backfilling with soil, and planting seedlings is as follows.

[0033] 1. Disinfection and sterilization

[0034] like Figure 1 As shown, 1-2 months before the seedlings are planted, dig a planting hole (length, width and depth 50cm×50cm×40cm). The excavated soil must be sealed and stored, and then transported and disinfected. Sprinkle the planting hole and the area 1m outside the planting hole. The drugs can be selected from Horlicks, Opel, Shibaoke and other drugs. The soil layer above 0.5m deep is required to be moist. Use fungicides diluted according to the required proportion of the drug. Cover with mulch after sprinkling to ensure the efficacy of the drug and try to kill or reduce the number of brown root pathogens in the surrounding soil.

[0035] 2. Set up root guard board

[0036] like Figure 2 As shown, a continuous root barrier board (black polyvinyl chloride PVC material, single layer thickness 1.5mm) is laid on the inner side wall of the planting hole. The overlapping length of the root barrier board interface is not less than 0.5m. A continuous root barrier membrane (black high-density polyethylene HDPE, single layer thickness ≥1.5mm) is laid at the bottom of the planting hole. The bottom of the root barrier membrane is perforated according to certain technical requirements, and about 100mm is exposed above the ground. The bottom of the planting hole is paved flat as a dividing strip. All overlapping parts should be sutured, looped or nailed.

[0037] To avoid water accumulation in the planting hole, the root barrier film is perforated. Each film is perforated with a spacing of 100mm×100mm and a hole diameter of 80-100mm (such as Figure 3 The planting hole forms a relatively closed environment and makes full use of gravity and osmotic pressure to prevent pathogens from contaminating the soil in the planting hole. When it rains or is watered manually, the accumulated water flows through the small holes at the bottom of the planting hole to avoid water accumulation.

[0038] 3. Apply basal fertilizer after returning soil

[0039] like Figure 4As shown, 1.0-1.5 kg of base fertilizer (the base fertilizer is organic fertilizer, and calculated by mass percentage, the organic matter content is more than 30%, and the contents of N, P, and K are more than 8%) and a small amount of guest soil (the mixing ratio of loess soil and peat soil is 3:1 by volume) are mixed evenly and spread on the bottom of the planting hole, and then the guest soil is backfilled to the specified height.

[0040] 4. Planting and Supporting

[0041] like Figure 5 As shown, after planting according to the design requirements, support is provided and a small reverse slope platform is built. Point A (the highest point of the platform) is 100 mm higher than point B (the lowest point of the platform close to the uphill slope).

[0042] The seedlings are supported by single wood. All supporting bamboos are selected with a tail diameter of not less than 30mm and a length of 2400mm. The lower end is inserted into the soil at least 600mm. The seedlings are used as the binding point with the supporting bamboo. They are bound with rubber strips. The contact points between the seedlings and the rubber strips are wrapped with non-woven fabrics or other materials as a protective layer (length not less than 100mm, thickness not less than 10mm). As the seedlings grow, the height of the binding point can be appropriately raised during the nurturing process. The seedling support is sampled every quarter and reinforced or adjusted once according to the actual situation. Before and after typhoons or heavy rains, the seedling support needs to be fully inspected and reinforced once.

[0043] The plan for controlling brown root disease using traditional prevention and control methods specifically includes the following steps: digging trenches to block the spread of pathogens, disinfecting the diseased soil, and planting seedlings.

[0044] In the planting area where traditional prevention and control methods are used, the trench is about 80cm deep (if the required depth cannot be reached, the weathered rock layer shall be dug as the standard), and plastic sheets are used for isolation. The main roots and fine roots of the felled trees remaining in the soil are dug out for pollution-free treatment.

[0045] Then treat the soil in the planting area with dazomethane fumigant (40 grams per square meter). Finally, plant new seedlings.

[0046] Table 1 Brown root disease incidence

[0047]

[0048]

[0049] The results of the survey and measurement showed that the growth indicators of the seedlings were not much different, but the seedlings planted by the present invention were not found to be infected with brown root pathogens, while the seedlings planted by the traditional method were found to be infected with brown root pathogens after 30 months (Table 1).

[0050] In summary, simply spraying pesticides cannot eradicate pathogens in forest soil. By laying root barriers and root barrier membranes, the external soil and external sterile planting soil are physically isolated to prevent unkilled pathogens in the forest soil from invading the seedling planting holes. Because the bottom root barrier membrane is designed with small holes, under the premise of maintaining water permeability, under the action of gravity and osmotic pressure, pathogens cannot contaminate the planting soil in a short time. After the seedlings grow for 5-6 years, the roots may grow through the small holes, but the disease resistance is enhanced and it is not easy to be infected by pathogens.

Claims

1. A method for restoring brown root root diseased forests, characterized in that: The following steps are involved: S1. Dig the planting hole 1-2 months before planting the seedlings, and disinfect and sterilize the planting hole and the area 1m around the planting hole; S2. A root barrier is laid on the side wall of the planting hole, and a root barrier film is laid at the bottom of the planting hole; the root barrier film is punched with small holes with a spacing of 100mm×100mm and a hole diameter of 80-100mm; S3. Mix 1.0-1.5kg of basal fertilizer with a small amount of imported soil and spread it on the bottom of the planting hole, and backfill with imported soil; S4. Planting seedlings.

2. The method according to claim 1, characterized in that The disinfection and sterilization in step S1 is performed by spraying with a fungicide of appropriate concentration until the soil at a depth of more than 0.5 m is moistened.

3. The method according to claim 1, characterized in that After the disinfection and sterilization in step S1, the step of covering with a ground film is also included.

4. The method according to claim 1, characterized in that: The thickness of the root blocking plate and the root barrier membrane in step S2 is 1.5 mm.

5. The method according to claim 1, characterized in that The imported soil in step S3 is loess soil and peat soil mixed in a volume ratio of 3:

1.

6. The method according to claim 1, characterized in that The base fertilizer in step S3 is an organic fertilizer, and calculated by mass percentage, the organic matter content is more than 30%, and the contents of N, P and K are more than 8%.

7. The method according to claim 1, characterized in that The step S4 further includes a step of supporting the seedlings.

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