Method for directionally cultivating single large-diameter target tree in eucalyptus

Abstract

The invention discloses a method for directionally cultivating a single large-diameter target tree in eucalyptus, and relates to the technical field of forest cultivation, and the method comprises the following steps: selecting a forest land; selecting tree species; afforestation; performing tending; by implementing the medium-large diameter target tree single-plant directional cultivation technology, firstly, the forest tree cultivation time is prolonged, the rotation cutting generations can be reduced, the interference intensity of human activities on the forest land is reduced, and the soil conservation capacity is enhanced; and secondly, intermediate cutting is carried out on the original forest stand during cultivation of the medium-large-diameter wood, after intermediate cutting, the ecological space for forest growth is improved, forest growth is promoted, meanwhile, the illumination intensity under the forest is enhanced, and the diversity of vegetation under the forest is increased, so that the problem of single forest stand structure is integrally improved, and the risk of pest and disease damage is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of forest cultivation, and more particularly to a method for directional cultivation of large-diameter target tree single plants in eucalyptus. Background Art

[0002] Eucalyptus has strong adaptability, excellent material, wide range of uses and significant benefits. After decades of domestication, improvement and breeding, eucalyptus has become the fastest growing, largest planting and best localized fast-growing and high-yield exotic timber species in South China. According to incomplete statistics, the area of ​​eucalyptus plantations in China is more than 80 million mu, and the area of ​​eucalyptus plantations in Guangxi Zhuang Autonomous Region is 45.5 million mu. At present, the area, volume and timber production of eucalyptus plantations in Guangxi Zhuang Autonomous Region rank first in the country.

[0003] At present, eucalyptus plantations are mainly developed in large-scale by using eucalyptus clone seedlings, short rotation period, multiple generations of continuous planting and concentrated continuous plots. After nearly 30 years of artificial planting, some management drawbacks have gradually emerged, such as the simple forest structure caused by single clone seedlings, excessive disturbance of soil by human activities due to short rotation period, excessive consumption of soil fertility due to multiple generations of continuous planting, and high risk of pests and diseases caused by concentrated continuous planting. Based on this, we provide a method for the directional cultivation of large-diameter target trees of eucalyptus. Summary of the invention

[0004] In order to solve the problems raised in the above background technology, the present invention provides a method for directional cultivation of large-diameter target tree plants in eucalyptus.

[0005] The present invention provides a method for directional cultivation of large-diameter target eucalyptus trees using the following technical solution:

[0006] A method for directional cultivation of large-diameter target tree single plants in eucalyptus, comprising the following steps:

[0007] S1. Selection of forest land: The afforestation area must have a rainfall greater than 600 mm, an altitude below 500 m, and a land slope less than 25°;

[0008] S2. Select tree species: Eucalyptus species with good growth and strong resistance are required;

[0009] S3. Afforestation:

[0010] Dig holes in the forest with a width of 40cm to 60cm, a depth of 30cm to 50cm, and a bottom width of 30cm to 40cm;

[0011] After land preparation, use organic fertilizer with an organic matter content of more than 40% as base fertilizer, put it into the bottom of the hole and mix it with a small amount of topsoil, then continue to backfill until the hole is full;

[0012] The afforestation density of Class I sites is 1250 plants / hm2 to 1666 plants / hm2; the afforestation density of Class II sites is 1428 plants / hm2 to 1666 plants / hm2;

[0013] Plant the seedlings after the soil in the hole is thoroughly wet. When planting, the bottom of the seedling roots should be more than 5 cm away from the soil mixed with base fertilizer. Cover the soil with a height of 2 cm above the nutrient surface. After the soil is compacted, a layer of loose soil with a thickness of 2 cm to 3 cm is added to the surface.

[0014] S4. Nurturing: According to the vegetation growth, the quantity and distribution of felled residues in the afforestation area, weeds are removed and comprehensive cleaning is carried out. The cleared weeds and felled residues are returned to the forest land in the form of strip piles and decay. The height of the weeds after cleaning is ≤10cm;

[0015] S5. Top dressing: After land preparation, use special fertilizer with organic matter content greater than 15%, total nutrient content of N+P205+K2O greater than 25%~30%, and trace element B+Zn+Cu content of 0.15%~0.65% as base fertilizer, 250g per hole. Put the fertilizer at the bottom of the hole and mix it with a small amount of topsoil, then continue to backfill until the hole is full.

[0016] Preferably, in S3, holes are dug on the forest land, and the holes are dug parallel to the contour lines and perpendicular to the contour lines.

[0017] A method for directional cultivation of large-diameter target tree single plants in eucalyptus, further comprising the following steps:

[0018] S6. Pest and disease control:

[0019] Prevention and control of leaf diseases: In the early stage of the disease, spray 1000 times of 70% methyl thiophanate in the diseased area and its surroundings for 2 to 3 times in a row;

[0020] Prevention and control of branch and trunk diseases: In the early stage of the disease, spray 1000 times diluted 70% methyl thiophanate, and remove and burn seriously diseased plants and branches in time;

[0021] Prevention and control of root diseases: If diseased seedlings or plants are found, they should be immediately removed and destroyed, and potassium permanganate (1%) and bleaching powder (1%) should be sprayed on the site of occurrence and its surroundings for disinfection.

[0022] Preferably, S6 also includes:

[0023] Termite control: Before planting, soak the seedling nutrition cup with 1000 times diluted eucalyptus termite prevention agent for 3 to 5 seconds for preventive treatment;

[0024] Tung oil leaf moth control: spray Bacillus thuringiensis wettable powder (16000IU / mg) 1000 times diluted;

[0025] Eucalyptus bat moth control:

[0026] Physical control: Use a bendable object with a certain hardness to repeatedly pierce the insect tunnel, causing the larvae to be injured and die;

[0027] Chemical control: inject 3 ml of 4.5% highly effective cypermethrin emulsifiable concentrate 500 times into the borer tunnel;

[0028] Biological control: During the larval and pupal stages of the eucalyptus bat moth, use Beauveria bassiana powder to spray 0.5 catties / mu to 1 catties / mu in the forest.

[0029] A method for directional cultivation of large-diameter target tree single plants in eucalyptus, further comprising the following steps:

[0030] S7. Thinning: Thinning shall be carried out in forest stands that are targeted for the cultivation of medium-diameter and large-diameter eucalyptus timber. When the forest stand density is ≥ 0.8, thinning shall account for 30% to 35% of the number of trees per unit land area.

[0031] A method for directional cultivation of large-diameter target tree single plants in eucalyptus, further comprising the following steps:

[0032] S8. Felling piles and cultivating soil: loosen the soil once within one month after felling. For forest land suitable for mechanized farming, loosen the soil along the rows with a width of 60% of the row spacing and a depth of >20cm.

[0033] Preferably, in S8, for forest land that is not suitable for mechanized farming, the soil is loosened artificially around the tree stump, with the stump as the center, and the soil within a range of 1 m is loosened to a depth of >20 cm.

[0034] A method for directional cultivation of large-diameter target tree single plants in eucalyptus, further comprising the following steps:

[0035] S9. Determining the sprouts: When the height of the sprouts reaches 1.0m~1.5m, the first determination of the plants begins.

[0036] Preferably, in step S9, in areas subject to typhoon hazards, 2 to 3 vigorously growing sprouts are retained on each pile, and after the typhoon season, a second transplanting is carried out, with one of the fastest growing and strongest sprouts retained on each pile.

[0037] Preferably, in step S9, one transplanting can be carried out in areas without typhoon damage, with one sprout strip retained for each pile, and the forest stand tending after transplanting is the same as that of new afforestation.

[0038] In summary, the present invention includes the following beneficial technical effects:

[0039] By implementing the technology of directional cultivation of medium- and large-diameter target trees, firstly, the tree cultivation time is extended, the number of rotation generations can be reduced, the intensity of interference from human activities on forest land is reduced, and the soil conservation capacity is enhanced; secondly, the cultivation of medium- and large-diameter timber will involve thinning of the original forest stands. After thinning, the ecological space for tree growth is improved, tree growth is promoted, while also enhancing the intensity of light under the forest and increasing the diversity of vegetation under the forest, thereby improving the overall problem of the single forest stand structure and reducing the risk of diseases and pests; it can increase the growth of individual eucalyptus trees and increase the nutrient accumulation function of the forest, and enhance the ecological functions of the eucalyptus forest ecosystem, such as soil conservation, plant diversity protection, and water conservation, thereby enhancing the productivity and ecosystem stability of eucalyptus plantations as a whole and achieving the goal of improving the quality and efficiency of eucalyptus plantations. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 The present invention is a flowchart of a method for directional cultivation of large-diameter target tree single plants in eucalyptus according to an embodiment of the present invention. DETAILED DESCRIPTION

[0041] The following is combined with Figure 1 The present invention is described in further detail.

[0042] It should be noted that the drawings are schematic and not to scale. For the sake of clarity and convenience, the relative sizes and proportions of the parts shown in the drawings are exaggerated or reduced in size, and any size is only illustrative and not restrictive. In addition, the same reference symbol is used for the same structure, element or accessory appearing in more than two figures to reflect similar features.

[0043] Embodiment 1

[0044] The embodiment of the present invention discloses a method for directional cultivation of large-diameter target tree single plants in eucalyptus, comprising the following steps:

[0045] S1. Selection of forest land: The afforestation area must have a rainfall greater than 600 mm, an altitude below 500 m, and a land slope less than 25°;

[0046] S2. Selection of tree species: Eucalyptus species or their clones with excellent growth and strong resistance are required;

[0047] S3. Afforestation:

[0048] Dig holes in the forest with a width of 40cm to 60cm, a depth of 30cm to 50cm, and a bottom width of 30cm to 40cm;

[0049] After land preparation, use organic fertilizer with an organic matter content of more than 40% as base fertilizer, put it into the bottom of the hole and mix it with a small amount of topsoil, then continue to backfill until the hole is full;

[0050] The afforestation density of Class I sites is 1250 plants / hm2 to 1666 plants / hm2; the afforestation density of Class II sites is 1428 plants / hm2 to 1666 plants / hm2;

[0051] Plant the seedlings after the soil in the hole is thoroughly wet. When planting, the bottom of the seedling roots should be more than 5 cm away from the soil mixed with base fertilizer. Cover the soil with a height of 2 cm above the nutrient surface. After the soil is compacted, a layer of loose soil with a thickness of 2 cm to 3 cm is added to the surface.

[0052] S4. Nurturing: According to the vegetation growth, the quantity and distribution of felled residues in the afforestation area, use manual or mechanical methods to remove or cut them, and implement comprehensive or strip-shaped clearing. The cleared weeds and felled residues are returned to the forest land in the form of strip-shaped piles and decay. The height of the weeds after clearing should be ≤10cm;

[0053] S5. Top dressing: After land preparation, use special fertilizer with 15% organic matter content, 25% total nutrient content of N+P205+K2O, and 0.15% content of trace elements B+Zn+Cu as base fertilizer, 250g per hole. Put the fertilizer at the bottom of the hole and mix it with a small amount of topsoil, then continue to backfill until the hole is full.

[0054] Specifically, in S3, holes are dug on the forest land, and the holes are dug parallel to the contour lines and perpendicular to the contour lines.

[0055] Specifically, the following steps are also included:

[0056] S6. Pest and disease control:

[0057] Prevention and control of leaf diseases: In the early stage of the disease, spray 1000 times of 70% methyl thiophanate or 1000 times of 75% chlorothalonil in the diseased area and its surroundings for prevention and control, and spray 2 to 3 times continuously;

[0058] Prevention and control of branch and trunk diseases: In the early stage of the disease, spray 70% methyl thiophanate 1000 times solution or 10% difenoconazole 200 times solution. If seriously diseased plants or branches are found, remove and burn them in time.

[0059] Prevention and control of root diseases: If diseased seedlings or plants are found, they should be immediately removed and destroyed, and the site of occurrence and its surroundings should be sprayed with potassium permanganate (1%) or bleaching powder (1%) for disinfection, or the roots should be rinsed with 1000 times diluted methyl thiophanate.

[0060] Specifically, S6 also includes:

[0061] Termite control: Before planting, soak the seedling nutrition cup with 1000 times diluted eucalyptus termite prevention agent produced by Guangxi Zhuang Autonomous Region Forestry Science Research Institute for 3 to 5 seconds for preventive treatment;

[0062] Control of tung leaf moth: spray 1000 times of Bacillus thuringiensis wettable powder (16000IU / mg), 1000 times of 25% suspension concentrate of 11 for killing young veins, 4000 times of 0.6% avermectin emulsifiable concentrate, and 5000 times of 2.5% deltamethrin emulsifiable concentrate;

[0063] Eucalyptus bat moth control:

[0064] Physical control: Use thin iron wire or iron awn base and other objects that can be bent and have a certain hardness to repeatedly pierce the worm tunnel, causing the larvae to be injured and die (use pepper water with a ratio of 1:3 to inject the worm tunnel, and kill it with a hard object after it crawls out of the hole);

[0065] Chemical control: Use 3 ml of 500 times dilution of 4.5% highly effective cypermethrin emulsifiable concentrate to inject into the borers, or use 5 ml of 200 times dilution of 10% imidacloprid wettable powder to inject into the borers, or use 3 ml of 2.0% avermectin microcapsule suspension (100-500 times) to inject into the borers.

[0066] Biological control: During the larval and pupal stages of the eucalyptus bat moth, use Beauveria bassiana powder to spray 0.5 catties / mu to 1 catties / mu in the forest;

[0067] The control is carried out by injecting Beauveria bassiana spore solution (concentration 1.0×107 / ml) into the boreholes. The specific method is: uncover the insect bag, inject 1 ml to 2 ml of Beauveria bassiana spore solution into the larval borehole with a syringe, and then cover the insect bag back on the hole.

[0068] Specifically, the following steps are also included:

[0069] S7. Thinning: Thinning should be carried out on the principle of removing the weak and retaining the strong, removing the inferior and retaining the superior, removing the harmful and retaining the beneficial, and maintaining uniformity. Thinning should be carried out in forest stands that are targeted for the cultivation of medium-diameter and large-diameter eucalyptus timber. When the forest stand density is ≥0.8, 30% to 35% of the number of trees per unit land area should be thinned.

[0070] Specifically, the following steps are also included:

[0071] S8. Soil cultivation after felling: loosen the soil once within one month after felling. For forest land suitable for mechanized farming, loosen the soil along the rows with a width of 60% of the row spacing and a depth of >20cm. For forest land not suitable for mechanized farming, loosen the soil around the stumps manually, with the felled stump as the center, and loosen the soil within a range of 1m to a depth of >20cm.

[0072] Specifically, the following steps are also included:

[0073] S9. Pinning: When the height of the sprout strips reaches 1.0m~1.5m, the first pinning begins. In areas with typhoon hazards, retain 2~3 vigorously growing sprout strips for each pile. After the typhoon season, the second pinning is carried out, retaining one of the fastest growing and strongest sprout strips for each pile. In areas without typhoon hazards, one pinning can be carried out, retaining one sprout strip for each pile. The forest stand care after pinning is the same as that of new afforestation.

[0074] According to the vegetation growth, the quantity and distribution of felled residues in the afforestation area, manual or mechanical methods are used to remove or cut the residues, and comprehensive or strip-shaped clearing is carried out. The cleared weeds and felled residues are returned to the forest land in the form of strip-shaped piles and decay. The height of the weeds and the fallen residues after clearing should be ≤10cm.

[0075] After land preparation, use a special fertilizer with an organic matter content of 15%, a total nutrient content of N+P205+K2O of 25%, and a content of trace elements B+Zn+Cu of 0.15% as base fertilizer, 250g per hole, put the fertilizer into the bottom of the hole and mix it with a small amount of topsoil, and then continue to backfill until the hole is full;

[0076] In the early stage of the disease, spray 1000 times of 70% methyl thiophanate or 1000 times of 75% chlorothalonil in the diseased area and its surroundings for prevention and control, and spray 2 to 3 times continuously;

[0077] Branch and trunk disease prevention

[0078] In the early stage of the disease, spray 70% methyl thiophanate 1000 times solution or 10% difenoconazole 200 times solution. If you find seriously diseased plants or branches, remove and burn them in time;

[0079] Root disease control

[0080] If diseased seedlings or plants are found, they should be removed and destroyed immediately, and potassium permanganate (1%) or bleaching powder (1%) should be sprayed on the site and its surroundings for disinfection, or the roots should be rinsed with 1000 times diluted methyl thiophanate;

[0081] Termite Control

[0082] Before planting, soak the seedling nutrition cup with 1000 times diluted eucalyptus termite prevention agent produced by Guangxi Zhuang Autonomous Region Forestry Science Research Institute for 3 to 5 seconds for preventive treatment;

[0083] Tung oil leaf moth control

[0084] Spray Bacillus thuringiensis wettable powder (16000 IU / mg) 1000 times diluted or spray 25% Miyoumai No. 11 suspension 1000 times diluted or spray 0.6% Avermectin EC 4000 times diluted or spray 2.5% Deltamethrin EC 5000 times diluted;

[0085] Eucalyptus bat moth control

[0086] Physical control: Use thin iron wire or iron awn base and other objects that can be bent and have a certain hardness to repeatedly pierce the worm tunnel, causing the larvae to be injured and die. Or use pepper water with a ratio of 1:3 to inject the worm tunnel, and kill it with a hard object after it crawls out of the hole;

[0087] Chemical control: 4.5% highly effective cypermethrin emulsifiable concentrate (500 times 3 ml) is used to inject into the borer tunnels; 10% imidacloprid wettable powder (200 times 5 ml) is used to inject into the borer tunnels; 2.0% avermectin microcapsule suspension (100-500 times) is used to inject into the borer tunnels;

[0088] Biological control: During the larval and pupal stages of the eucalyptus bat moth, you can use Beauveria bassiana powder to spray 0.5 catties / mu to 1 catties / mu in the forest, and inject Beauveria bassiana liquid (concentration 1.0×107 cells / ml) into the borehole for prevention and control. The specific method is to uncover the insect bag, inject 1 ml to 2 ml of Beauveria bassiana spore liquid into the larval borehole with a syringe, and cover the insect bag back to the hole;

[0089] Thinning should be carried out based on the principles of removing the weak and retaining the strong, removing the inferior and retaining the superior, removing the harmful and retaining the beneficial, and maintaining uniformity. Thinning should be carried out in forest stands that are targeted for the cultivation of medium-diameter and large-diameter eucalyptus timber. When the stand density is ≥0.8, 30% to 35% of the number of trees per unit area should be thinned.

[0090] Embodiment 2

[0091] The embodiment of the present invention discloses a method for directional cultivation of large-diameter target tree single plants in eucalyptus, comprising the following steps:

[0092] S1. Selection of forest land: The afforestation area must have a rainfall greater than 600 mm, an altitude below 500 m, and a land slope less than 25°;

[0093] S2. Selection of tree species: Eucalyptus species or their clones with excellent growth and strong resistance are required;

[0094] S3. Afforestation:

[0095] Dig holes in the forest with a width of 40cm to 60cm, a depth of 30cm to 50cm, and a bottom width of 30cm to 40cm;

[0096] After land preparation, use organic fertilizer with an organic matter content of more than 40% as base fertilizer, put it into the bottom of the hole and mix it with a small amount of topsoil, then continue to backfill until the hole is full;

[0097] The afforestation density of Class I sites is 1250 plants / hm2 to 1666 plants / hm2; the afforestation density of Class II sites is 1428 plants / hm2 to 1666 plants / hm2;

[0098] Plant the seedlings after the soil in the hole is thoroughly wet. When planting, the bottom of the seedling roots should be more than 5 cm away from the soil mixed with base fertilizer. Cover the soil with a height of 2 cm above the nutrient surface. After the soil is compacted, a layer of loose soil with a thickness of 2 cm to 3 cm is added to the surface.

[0099] S4. Nurturing: According to the vegetation growth, the quantity and distribution of felled residues in the afforestation area, use manual or mechanical methods to remove or cut them, and implement comprehensive or strip-shaped clearing. The cleared weeds and felled residues are returned to the forest land in the form of strip-shaped piles and decay. The height of the weeds after clearing should be ≤10cm;

[0100] S5. Top dressing: After land preparation, use special fertilizer with organic matter content greater than 20%, total nutrient content of N+P205+K2O greater than 27%, and trace element B+Zn+Cu content of 0.35% as base fertilizer, 250g per hole. Put the fertilizer at the bottom of the hole and mix it with a small amount of topsoil, then continue to backfill until the hole is full.

[0101] Specifically, in S3, holes are dug on the forest land, and the holes are dug parallel to the contour lines and perpendicular to the contour lines.

[0102] Specifically, the following steps are also included:

[0103] S6. Pest and disease control:

[0104] Prevention and control of leaf diseases: In the early stage of the disease, spray 1000 times of 70% methyl thiophanate or 1000 times of 75% chlorothalonil in the diseased area and its surroundings for prevention and control, and spray 2 to 3 times continuously;

[0105] Prevention and control of branch and trunk diseases: In the early stage of the disease, spray 70% methyl thiophanate 1000 times solution or 10% difenoconazole 200 times solution. If seriously diseased plants or branches are found, remove and burn them in time.

[0106] Prevention and control of root diseases: If diseased seedlings or plants are found, they should be immediately removed and destroyed, and the site of occurrence and its surroundings should be sprayed with potassium permanganate (1%) or bleaching powder (1%) for disinfection, or the roots should be rinsed with 1000 times diluted methyl thiophanate.

[0107] Specifically, S6 also includes:

[0108] Termite control: Before planting, soak the seedling nutrition cup with 1000 times diluted eucalyptus termite prevention agent produced by Guangxi Zhuang Autonomous Region Forestry Science Research Institute for 3 to 5 seconds for preventive treatment;

[0109] Control of tung leaf moth: spray 1000 times of Bacillus thuringiensis wettable powder (16000IU / mg), 1000 times of 25% suspension concentrate of 11 for killing young veins, 4000 times of 0.6% avermectin emulsifiable concentrate, and 5000 times of 2.5% deltamethrin emulsifiable concentrate;

[0110] Eucalyptus bat moth control:

[0111] Physical control: Use thin iron wire or iron awn base and other objects that can be bent and have a certain hardness to repeatedly pierce the worm tunnel, causing the larvae to be injured and die (use pepper water with a ratio of 1:3 to inject the worm tunnel, and kill it with a hard object after it crawls out of the hole);

[0112] Chemical control: Use 3 ml of 500 times dilution of 4.5% highly effective cypermethrin emulsifiable concentrate to inject into the borers, or use 5 ml of 200 times dilution of 10% imidacloprid wettable powder to inject into the borers, or use 3 ml of 2.0% avermectin microcapsule suspension (100-500 times) to inject into the borers.

[0113] Biological control: During the larval and pupal stages of the eucalyptus bat moth, use Beauveria bassiana powder to spray 0.5 catties / mu to 1 catties / mu in the forest;

[0114] The control is carried out by injecting Beauveria bassiana spore solution (concentration 1.0×107 / ml) into the boreholes. The specific method is: uncover the insect bag, inject 1 ml to 2 ml of Beauveria bassiana spore solution into the larval borehole with a syringe, and then cover the insect bag back on the hole.

[0115] Specifically, the following steps are also included:

[0116] S7. Thinning: Thinning should be carried out on the principle of removing the weak and retaining the strong, removing the inferior and retaining the superior, removing the harmful and retaining the beneficial, and maintaining uniformity. Thinning should be carried out in forest stands that are targeted for the cultivation of medium-diameter and large-diameter eucalyptus timber. When the forest stand density is ≥0.8, 30% to 35% of the number of trees per unit land area should be thinned.

[0117] Specifically, the following steps are also included:

[0118] S8. Soil cultivation after felling: loosen the soil once within one month after felling. For forest land suitable for mechanized farming, loosen the soil along the rows with a width of 60% of the row spacing and a depth of >20cm. For forest land not suitable for mechanized farming, loosen the soil around the stumps manually, with the felled stump as the center, and loosen the soil within a range of 1m to a depth of >20cm.

[0119] Specifically, the following steps are also included:

[0120] S9. Pinning: When the height of the sprout strips reaches 1.0m~1.5m, the first pinning begins. In areas with typhoon hazards, retain 2~3 vigorously growing sprout strips for each pile. After the typhoon season, the second pinning is carried out, retaining one of the fastest growing and strongest sprout strips for each pile. In areas without typhoon hazards, one pinning can be carried out, retaining one sprout strip for each pile. The forest stand care after pinning is the same as that of new afforestation.

[0121] According to the vegetation growth, the quantity and distribution of felled residues in the afforestation area, manual or mechanical methods are used to remove or cut the residues, and comprehensive or strip-shaped clearing is carried out. The cleared weeds and felled residues are returned to the forest land in the form of strip-shaped piles and decay. The height of the weeds and the fallen residues after clearing should be ≤10cm.

[0122] After land preparation, use a special fertilizer with an organic matter content greater than 20%, a total nutrient content of N+P205+K2O greater than 27%, and a trace element B+Zn+Cu content of 0.35% as base fertilizer, 250g per hole, put the fertilizer into the bottom of the hole and mix it with a small amount of topsoil, then continue to backfill until the hole is full;

[0123] In the early stage of the disease, spray 1000 times of 70% methyl thiophanate or 1000 times of 75% thiophanate-methyl in the diseased area and its surroundings for prevention and control, and spray continuously for 2 to 3 times;

[0124] Branch and trunk disease prevention

[0125] In the early stage of the disease, spray 1000 times of 70% methyl thiophanate or 200 times of 10% difenoconazole. If seriously diseased plants or branches are found, remove and burn them in time;

[0126] Root disease control

[0127] If diseased seedlings or plants are found, they should be removed and destroyed immediately, and potassium permanganate (1%) or bleaching powder (1%) should be sprayed on the site and its surroundings for disinfection, or the roots should be rinsed with 1000 times diluted methyl thiophanate;

[0128] Termite Control

[0129] Before planting, soak the seedling nutrition cup with 1000 times diluted eucalyptus termite prevention agent produced by Guangxi Zhuang Autonomous Region Forestry Science Academy for 3 to 5 seconds for preventive treatment;

[0130] Tung oil leaf moth control

[0131] Spray Bacillus thuringiensis wettable powder (16000 IU / mg) 1000 times diluted or spray 25% Miyoumai No. 11 suspension 1000 times diluted or spray 0.6% Avermectin EC 4000 times diluted or spray 2.5% Deltamethrin EC 5000 times diluted;

[0132] Eucalyptus bat moth control

[0133] Physical control: Use thin iron wire or iron awn base and other objects that can be bent and have a certain hardness to repeatedly pierce the worm tunnel, causing the larvae to be injured and die. Or use pepper water with a ratio of 1:3 to inject the worm tunnel, and kill it with a hard object after it crawls out of the hole;

[0134] Chemical control: 4.5% highly effective cypermethrin emulsifiable concentrate (500 times 3 ml) is used to inject into the borer tunnels; 10% imidacloprid wettable powder (200 times 5 ml) is used to inject into the borer tunnels; 2.0% avermectin microcapsule suspension (100-500 times) is used to inject into the borer tunnels;

[0135] Biological control: During the larval and pupal stages of the eucalyptus bat moth, you can use Beauveria bassiana powder to spray 0.5 catties / mu to 1 catties / mu in the forest, and inject Beauveria bassiana liquid (concentration 1.0×107 cells / ml) into the borehole for prevention and control. The specific method is to uncover the insect bag, inject 1 ml to 2 ml of Beauveria bassiana spore liquid into the larval borehole with a syringe, and cover the insect bag back to the hole;

[0136] Thinning should be carried out based on the principles of removing the weak and retaining the strong, removing the inferior and retaining the superior, removing the harmful and retaining the beneficial, and maintaining uniformity. Thinning should be carried out in forest stands that are targeted for the cultivation of medium-diameter and large-diameter eucalyptus timber. When the stand density is ≥0.8, 30% to 35% of the number of trees per unit area should be thinned.

[0137] Embodiment 3

[0138] The embodiment of the present invention discloses a method for directional cultivation of large-diameter target tree single plants in eucalyptus, comprising the following steps:

[0139] S1. Selection of forest land: The afforestation area must have a rainfall greater than 600 mm, an altitude below 500 m, and a land slope less than 25°;

[0140] S2. Selection of tree species: Eucalyptus species or their clones with excellent growth and strong resistance are required;

[0141] S3. Afforestation:

[0142] Dig holes in the forest with a width of 40cm to 60cm, a depth of 30cm to 50cm, and a bottom width of 30cm to 40cm;

[0143] After land preparation, use organic fertilizer with an organic matter content of more than 40% as base fertilizer, put it into the bottom of the hole and mix it with a small amount of topsoil, then continue to backfill until the hole is full;

[0144] The afforestation density of Class I sites is 1250 plants / hm2 to 1666 plants / hm2; the afforestation density of Class II sites is 1428 plants / hm2 to 1666 plants / hm2;

[0145] Plant the seedlings after the soil in the hole is thoroughly wet. When planting, the bottom of the seedling roots should be more than 5 cm away from the soil mixed with base fertilizer. Cover the soil with a height of 2 cm above the nutrient surface. After the soil is compacted, a layer of loose soil with a thickness of 2 cm to 3 cm is added to the surface.

[0146] S4. Nurturing: According to the vegetation growth, the quantity and distribution of felled residues in the afforestation area, use manual or mechanical methods to remove or cut them, and implement comprehensive or strip-shaped clearing. The cleared weeds and felled residues are returned to the forest land in the form of strip-shaped piles and decay. The height of the weeds after clearing should be ≤10cm;

[0147] S5. Top dressing: After land preparation, use special fertilizer with organic matter content greater than 25%, total nutrient content of N+P205+K2O greater than 30%, and trace element B+Zn+Cu content of 0.65% as base fertilizer, 250g per hole. Put the fertilizer at the bottom of the hole and mix it with a small amount of topsoil, then continue to backfill until the hole is full.

[0148] Specifically, in S3, holes are dug on the forest land, and the holes are dug parallel to the contour lines and perpendicular to the contour lines.

[0149] Specifically, the following steps are also included:

[0150] S6. Pest and disease control:

[0151] Prevention and control of leaf diseases: In the early stage of the disease, spray 1000 times of 70% methyl thiophanate or 1000 times of 75% chlorothalonil in the diseased area and its surroundings for prevention and control, and spray 2 to 3 times continuously;

[0152] Prevention and control of branch and trunk diseases: In the early stage of the disease, spray 70% methyl thiophanate 1000 times solution or 10% difenoconazole 200 times solution. If seriously diseased plants or branches are found, remove and burn them in time.

[0153] Prevention and control of root diseases: If diseased seedlings or plants are found, they should be immediately removed and destroyed, and the site of occurrence and its surroundings should be sprayed with potassium permanganate (1%) or bleaching powder (1%) for disinfection, or the roots should be rinsed with 1000 times diluted methyl thiophanate.

[0154] Specifically, S6 also includes:

[0155] Termite control: Before planting, soak the seedling nutrition cup with 1000 times diluted eucalyptus termite prevention agent produced by Guangxi Zhuang Autonomous Region Forestry Science Research Institute for 3 to 5 seconds for preventive treatment;

[0156] Control of tung leaf moth: spray 1000 times of Bacillus thuringiensis wettable powder (16000IU / mg), 1000 times of 25% suspension concentrate of 11 for killing young veins, 4000 times of 0.6% avermectin emulsifiable concentrate, and 5000 times of 2.5% deltamethrin emulsifiable concentrate;

[0157] Eucalyptus bat moth control:

[0158] Physical control: Use thin iron wire or iron awn base and other objects that can be bent and have a certain hardness to repeatedly pierce the worm tunnel, causing the larvae to be injured and die (use pepper water with a ratio of 1:3 to inject the worm tunnel, and kill it with a hard object after it crawls out of the hole);

[0159] Chemical control: Use 3 ml of 500 times dilution of 4.5% highly effective cypermethrin emulsifiable concentrate to inject into the borers, or use 5 ml of 200 times dilution of 10% imidacloprid wettable powder to inject into the borers, or use 3 ml of 2.0% avermectin microcapsule suspension (100-500 times) to inject into the borers.

[0160] Biological control: During the larval and pupal stages of the eucalyptus bat moth, use Beauveria bassiana powder to spray 0.5 catties / mu to 1 catties / mu in the forest;

[0161] The control is carried out by injecting Beauveria bassiana spore solution (concentration 1.0×107 / ml) into the boreholes. The specific method is: uncover the insect bag, inject 1 ml to 2 ml of Beauveria bassiana spore solution into the larval borehole with a syringe, and then cover the insect bag back on the hole.

[0162] Specifically, the following steps are also included:

[0163] S7. Thinning: Thinning should be carried out on the principle of removing the weak and retaining the strong, removing the inferior and retaining the superior, removing the harmful and retaining the beneficial, and maintaining uniformity. Thinning should be carried out in forest stands that are targeted for the cultivation of medium-diameter and large-diameter eucalyptus timber. When the forest stand density is ≥0.8, 30% to 35% of the number of trees per unit land area should be thinned.

[0164] Specifically, the following steps are also included:

[0165] S8. Soil cultivation after felling: loosen the soil once within one month after felling. For forest land suitable for mechanized farming, loosen the soil along the rows with a width of 60% of the row spacing and a depth of >20cm. For forest land not suitable for mechanized farming, loosen the soil around the stumps manually, with the felled stump as the center, and loosen the soil within a range of 1m to a depth of >20cm.

[0166] Specifically, the following steps are also included:

[0167] S9. Pinning: When the height of the sprout strips reaches 1.0m~1.5m, the first pinning begins. In areas with typhoon hazards, retain 2~3 vigorously growing sprout strips for each pile. After the typhoon season, the second pinning is carried out, retaining one of the fastest growing and strongest sprout strips for each pile. In areas without typhoon hazards, one pinning can be carried out, retaining one sprout strip for each pile. The forest stand care after pinning is the same as that of new afforestation.

[0168] According to the vegetation growth, the quantity and distribution of felled residues in the afforestation area, manual or mechanical methods are used to remove or cut the residues, and comprehensive or strip-shaped clearing is carried out. The cleared weeds and felled residues are returned to the forest land in the form of strip-shaped piles and decay. The height of the weeds and the fallen residues after clearing should be ≤10cm.

[0169] After land preparation, use a special fertilizer with an organic matter content greater than 25%, a total nutrient content of N+P205+K2O greater than 30%, and a trace element B+Zn+Cu content of 0.65% as base fertilizer, 250g per hole, put the fertilizer into the bottom of the hole and mix it with a small amount of topsoil, then continue to backfill until the hole is full;

[0170] In the early stage of the disease, spray 1000 times of 70% methyl thiophanate or 1000 times of 75% chlorothalonil in the diseased area and its surroundings for prevention and control, and spray 2 to 3 times continuously;

[0171] Branch and trunk disease prevention

[0172] In the early stage of the disease, spray 70% methyl thiophanate 1000 times solution or 10% difenoconazole 200 times solution. If you find seriously diseased plants or branches, remove and burn them in time;

[0173] Root disease control

[0174] If diseased seedlings or plants are found, they should be removed and destroyed immediately, and potassium permanganate (1%) or bleaching powder (1%) should be sprayed on the site and its surroundings for disinfection, or the roots should be rinsed with 1000 times diluted methyl thiophanate;

[0175] Termite Control

[0176] Before planting, soak the seedling nutrition cup with 1000 times diluted eucalyptus termite prevention agent produced by Guangxi Zhuang Autonomous Region Forestry Science Research Institute for 3 to 5 seconds for preventive treatment;

[0177] Tung oil leaf moth control

[0178] Spray Bacillus thuringiensis wettable powder (16000I U / mg) 1000 times diluted or spray 25% Miyoumai No. 11 suspension 1000 times diluted or spray 0.6% Avermectin emulsifiable concentrate 4000 times diluted or spray 2.5% Deltamethrin emulsifiable concentrate 5000 times diluted;

[0179] Eucalyptus bat moth control

[0180] Physical control: Use thin iron wire or iron awn base and other objects that can be bent and have a certain hardness to repeatedly pierce the worm tunnel, causing the larvae to be injured and die. Or use pepper water with a ratio of 1:3 to inject the worm tunnel, and kill it with a hard object after it crawls out of the hole;

[0181] Chemical control: 4.5% highly effective cypermethrin emulsifiable concentrate (500 times 3 ml) is used to inject into the borer tunnels; 10% imidacloprid wettable powder (200 times 5 ml) is used to inject into the borer tunnels; 2.0% avermectin microcapsule suspension (100-500 times) is used to inject into the borer tunnels;

[0182] Biological control: During the larval and pupal stages of the eucalyptus bat moth, you can use Beauveria bassiana powder to spray 0.5 catties / mu to 1 catties / mu in the forest, and inject Beauveria bassiana liquid (concentration 1.0×107 cells / ml) into the borehole for prevention and control. The specific method is to uncover the insect bag, inject 1 ml to 2 ml of Beauveria bassiana spore liquid into the larval borehole with a syringe, and cover the insect bag back to the hole;

[0183] Thinning should be carried out based on the principles of removing the weak and retaining the strong, removing the inferior and retaining the superior, removing the harmful and retaining the beneficial, and maintaining uniformity. Thinning should be carried out in forest stands that are targeted for the cultivation of medium-diameter and large-diameter eucalyptus timber. When the stand density is ≥0.8, 30% to 35% of the number of trees per unit area should be thinned.

[0184] Comparative Example

[0185] The selection of afforestation areas is relatively loose, and there are no strict requirements on conditions such as rainfall, altitude and plot slope. Choose woodland with rainfall less than 600mm, altitude higher than 500m or plot slope greater than 25°; choose tree species: eucalyptus species with excellent growth and strong resistance are required; dig holes in the forest land, with hole specifications of 40cm to 60cm wide, 30cm to 50cm deep, and 30cm to 40cm wide at the bottom; plant eucalyptus seedlings in the holes, and apply normal fertilization, tending and topdressing.

[0186] The test results are shown in the following table:

[0187] Soil conservation capacity Light intensity under forest Human disturbance intensity Embodiment 1 excellent Reasonable Few times Embodiment 2 excellent Reasonable Few times Embodiment 3 excellent Reasonable Few times Comparative Example generally There is incomplete irradiation Many times

[0188] It can be seen from the above table that by implementing the directional cultivation technology of medium-to-large diameter target trees, firstly, the tree cultivation time is extended, the number of rotation generations can be reduced, the intensity of interference from human activities on forest land is reduced, and the soil conservation capacity is enhanced; secondly, the cultivation of medium-to-large diameter timber will involve thinning of the original forest stands. After thinning, the ecological space for tree growth is improved, tree growth is promoted, while also enhancing the intensity of light under the forest and increasing the diversity of understory vegetation, thereby improving the overall problem of single forest structure and reducing the risk of diseases and insect pests; it can increase the growth of individual eucalyptus trees and increase the nutrient accumulation function of trees, as well as enhance the ecological functions of the eucalyptus forest ecosystem, such as soil conservation, plant diversity protection, and water conservation, thereby enhancing the productivity and ecosystem stability of eucalyptus plantations as a whole and achieving the goal of improving the quality and efficiency of eucalyptus plantations.

[0189] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for directional cultivation of large-diameter target tree single plants in eucalyptus, characterized in that: The following steps are involved: S1. Selection of forest land: The afforestation area must have a rainfall greater than 600 mm, an altitude below 500 m, and a land slope less than 25°; S2. Select tree species: Eucalyptus species with good growth and strong resistance are required; S3. Afforestation: Dig holes in the forest with a width of 40cm to 60cm, a depth of 30cm to 50cm, and a bottom width of 30cm to 40cm; After land preparation, use organic fertilizer with an organic matter content of more than 40% as base fertilizer, put it into the bottom of the hole and mix it with a small amount of topsoil, then continue to backfill until the hole is full; The afforestation density of Class I sites is 1250 plants / hm2 to 1666 plants / hm2; the afforestation density of Class II sites is 1428 plants / hm2 to 1666 plants / hm2; Plant the seedlings after the soil in the hole is thoroughly wet. When planting, the bottom of the seedling roots should be more than 5 cm away from the soil mixed with base fertilizer. Cover the soil with a height of 2 cm above the nutrient surface. After the soil is compacted, a layer of loose soil with a thickness of 2 cm to 3 cm is added to the surface. S4. Nurturing: According to the vegetation growth, the quantity and distribution of felled residues in the afforestation area, weeds are removed and comprehensive cleaning is carried out. The cleared weeds and felled residues are returned to the forest land in the form of strip piles and decay. The height of the weeds after cleaning is ≤10cm; S5. Top dressing: After land preparation, use special fertilizer with organic matter content greater than 15%, total nutrient content of N+P205+K2O greater than 25%~30%, and trace element B+Zn+Cu content of 0.15%~0.65% as base fertilizer, 250g per hole. Put the fertilizer at the bottom of the hole and mix it with a small amount of topsoil, then continue to backfill until the hole is full.

2. A method for directional cultivation of large-diameter target trees in eucalyptus according to claim 1, characterized in that: In S3, holes are dug in the forest floor, parallel to the contour lines and perpendicular to the contour lines.

3. A method for directional cultivation of large-diameter target trees in eucalyptus according to claim 1, characterized in that: The following steps are also included: S6. Pest and disease control: Prevention and control of leaf diseases: In the early stage of the disease, spray 1000 times of 70% methyl thiophanate in the diseased area and its surroundings for 2 to 3 times in a row; Prevention and control of branch and trunk diseases: In the early stage of the disease, spray 1000 times diluted 70% methyl thiophanate, and remove and burn seriously diseased plants and branches in time; Prevention and control of root diseases: If diseased seedlings or plants are found, they should be immediately removed and destroyed, and potassium permanganate (1%) and bleaching powder (1%) should be sprayed on the site of occurrence and its surroundings for disinfection.

4. A method for directional cultivation of large-diameter target trees in eucalyptus according to claim 3, characterized in that: Also included in the S6: Termite control: Before planting, soak the seedling nutrition cup with 1000 times diluted eucalyptus termite prevention agent for 3 to 5 seconds for preventive treatment; Tung oil leaf moth control: spray Bacillus thuringiensis wettable powder (16000IU / mg) 1000 times diluted; Eucalyptus bat moth control: Physical control: Use a bendable object with a certain hardness to repeatedly pierce the insect tunnel, causing the larvae to be injured and die; Chemical control: inject 3 ml of 4.5% highly effective cypermethrin emulsifiable concentrate 500 times into the borer tunnel; Biological control: During the larval and pupal stages of the eucalyptus bat moth, use Beauveria bassiana powder to spray 0.5 catties / mu to 1 catties / mu in the forest.

5. The method for directional cultivation of large-diameter target trees in eucalyptus according to claim 1, characterized in that: The following steps are also included: S7. Thinning: Thinning shall be carried out in forest stands targeting medium-diameter and large-diameter eucalyptus timber. When the forest stand density is ≥ 0.8, thinning shall account for 30% to 35% of the number of trees per unit land area.

6. A method for directional cultivation of large-diameter target trees in eucalyptus according to claim 1, characterized in that: The following steps are also included: S8. Felling piles and cultivating soil: loosen the soil once within one month after felling. For forest land suitable for mechanized farming, loosen the soil along the rows with a width of 60% of the row spacing and a depth of >20cm.

7. A method for directional cultivation of large-diameter target trees in eucalyptus according to claim 6, characterized in that: In S8, for forest land that is not suitable for mechanized farming, the soil is loosened artificially around the tree stumps. The soil within a range of 1m is loosened with the stump as the center, and the depth is >20cm.

8. The method for directional cultivation of large-diameter target trees in eucalyptus according to claim 1, characterized in that: The following steps are also included: S9. Determining the sprouts: When the height of the sprouts reaches 1.0m~1.5m, the first determination of the plants begins.

9. A method for directional cultivation of large-diameter target trees in eucalyptus according to claim 8, characterized in that: In step S9, in areas with typhoon hazards, 2 to 3 vigorously growing sprouts are retained for each pile, and the second planting is carried out after the typhoon season, and one of the fastest growing and strongest sprouts is retained for each pile.

10. The method for directional cultivation of large-diameter target trees in eucalyptus according to claim 1, characterized in that: In step S9, one transplanting can be carried out in areas without typhoon damage, with one sprout strip retained for each pile. The forest stand tending after transplanting is the same as that of new afforestation.

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