(1) Selection of seedlings: The quality of seedlings is one of the important factors affecting survival. In order to improve the survival rate and future effect, strict seedling selection must be carried out before transplantation. When selecting seedlings, in addition to the special requirements such as seedling size and tree shape, we should also pay attention to selecting seedlings with developed roots, strong growth, no pests and diseases, no mechanical damage and correct tree shape.
(2) The main quality standards of trees should be measured by height, crown width and DBH. Quality requirements: The trunk must be straight, with even branches, complete crown, avoiding bending and deflection, smooth trunk, and free of large nodules (unhealed scars with a diameter greater than 20mm) and foreign bodies coming out of the hole. Except for the color leaf type, the leaves are usually dark green, bright, leafy and full. The main anti-glare tree species are thick and flat, and it is strictly forbidden to fall off (falling off means that the leaves are more than 20 cm from the ground). Leaves are usually not yellow and white, and there are no pests or a large number of eggs parasitic. It is advisable to choose 3-5-year-old strong seedlings and avoid small old trees.
(3) The main quality standards of shrubs should be measured by tree height, crown width and ground diameter. Quality requirements: it is better to choose more branches and lower branches. Generally, the 1 branch should have more than 3 branches, and the branch point should not exceed 30cm. The color of green leaves is green, dark green and bright, and the color of colored leaves should be pure. Shrubs should be more branched and have dense and full leaves, especially some balls or shrubs need to be cut into various shapes, which requires higher density of branches and leaves. The diseased leaves of plants change from green to yellow, white or various variegated colors. Observe whether the leaves are bitten by insects, whether there are insects, or whether there are a lot of eggs parasitic.
(4) Choose the correct grass seeds, which shall not contain other weed seeds. The lawn is green and free from pests and diseases.
(5) When measuring seedling height, irrigation height, branch height, crown diameter and crown diameter, steel tape measure, tape measure or wooden ruler shall be used, and the reading shall be accurate to 65438±0.0cm. The inspection of seedling age and transplanting times shall be subject to the seedling file records before leaving the nursery. When all the seedlings are selected, they should be tied and listed. Make obvious marks to avoid making mistakes. A certain number of seedlings should be selected for standby.
Treatment and maintenance of seedlings before transplantation
(1) Before planting, measures should be taken, such as cutting roots, turning stumps, thinning and shaping, and applying more base fertilizer to ensure the survival rate of transplanting. At the same time, by means of trunk protection, root hydration, foliar spraying, pruning, wound disinfection and waxing, plant protection, etc., the adaptability and resistance of plants to migration are cultivated and enhanced, and the function of harvesting new fibrous roots is strengthened, so that the selected seedlings become "semi-finished products" that not only survive after planting, but also take shape at one time and grow well.
(2) If the soil where the seedlings grow is too dry, water them a few days in advance; On the contrary, when the soil is too wet, we should try to drain water in advance to facilitate the operation during excavation.
(3) Crown collection: For evergreen trees with low lateral branches and shrubs with huge crown clusters, especially thorny shrubs, in order to facilitate operation, the crown should be tied with straw ropes first. But pay attention to the tightness and don't damage the branches. Crown collection operation can also be combined with seedling selection.
(4) Prepare sharp seedling digging tools. When digging seedlings with soil balls, you should prepare suitable packaging materials such as cattail bags, straw ropes and plastic sheets.
(5) Trial excavation: In order to ensure that the seedling root system specifications meet the requirements, the seedling root system specifications should be excavated. Deciduous shrubs should only be transplanted to 1/3 of the seedling height, and the transplanted soil balls of evergreen trees should be about 10 times of the seedling breast (trunk) diameter.
Excavation of seedlings
(1) Migration sequence. When transplanting seedlings, according to the principle of high before low, skeleton trees should be first, then big shrubs, then small shrubs, ground cover and lawn. At the same time, according to the specific situation and weather changes, flexible adjustment, so as to ensure the workload of the construction period and ensure the quality survival rate.
(2) Before transplanting and digging seedlings, make full arrangements for tools, equipment, manpower and transportation capacity, so as to keep the digging and planting seedlings synchronized and coordinated, and avoid delays in digging and planting seedlings. It is required that the whole transplanting process of digging and transporting seeds should not exceed 24 hours.
(3) Manual seedling digging method and quality requirements for bare root transplantation:
According to the size of trees and seedlings, dig outside the specified root system specifications. Dig vertically around the seedlings to a certain depth with a sharp digging tool, and cut off all lateral roots. After cutting, dig deep and shake the seedlings, try to find deep and thick roots and cut off the bottom roots. When encountering thick roots, it is best to saw them off with a hand saw. Then gently put down the seedlings and break the surrounding clods. In short, when digging seedlings, we must protect the big roots from splitting and leave as many fibrous roots as possible.
Seedlings should be shipped immediately after digging. If it can't be transported for a while, you can bury the heel in the original pit and bury the root with wet soil. If it lasts for a long time, we should properly irrigate the soil according to the dryness of the soil to keep the temperature of the soil.
(4) Manual seedling digging method and quality requirements for ball seedlings with soil:
1) use soil balls to pick seedlings. The general requirement is that the specifications of soil balls should meet the specified size; Ensure that the soil ball is in good condition and the appearance is flat and smooth; The upper part is large and the lower part is slightly smaller, which looks like an apple. Tight packaging, straw rope tight but not loose. The bottom of the soil ball should be sealed to prevent soil leakage.
2) At the beginning of excavation, draw a circle with the trunk as the center according to the size of the soil ball, indicating the diameter of the soil ball. In order to ensure that the soil ball reaches the specified size, in general, the scope should be slightly expanded during excavation.
3) Remove the topsoil first, and after delineation, remove a layer of topsoil from the circle first, and the depth shall not damage the seedling roots on the surface.
4) After the topsoil is removed, dig trenches vertically downward along the outer edge of the circle. The width of the ditch is about 50-80 cm, which is convenient for operation. The width of the dug ditch should be basically the same. When you dig, trim the surface of the earth ball; Never trample or hit the edge of the soil ball during operation, so as not to damage the soil ball, and dig to the specified depth of the vertical diameter of the soil ball.
5) Cutting: After the soil ball is trimmed, it is slowly dug inward from the bottom ring, which is called "cutting". For soil balls with a diameter less than 50 cm, the subsoil can be directly hollowed out to transport the soil balls to the outer packaging of the pit; For soil balls larger than 50 cm, a part of subsoil center should be reserved to support the soil balls packed in the pit.
6) Pubao and straw rope should be soaked in water before packaging, so as to enhance the toughness of packaging materials and reduce brittle fracture and tensile fracture caused by binding.
A. If the diameter of the soil ball is less than 50 cm, take it out of the pit and pack it: first, put a bag of suitable size at the edge of the pit, hold the soil ball with both hands and gently put it in the middle of the bag. Then wrap the trunk longitudinally with wet straw rope and bind the package firmly.
B, loose soil and large-scale soil balls, you should look for a bag in the pit. The method is: cut two wet pouches of suitable size from one side of the bag to the center of the bottom, and cover the bottom with one and the top with the other; At the joint of two cattails, tie some straw ropes to fix cattails, and then tie longitudinal straw ropes as required.
C, longitudinal straw rope binding method: first, bind the soaked straw rope to the stem of the trunk and fix it around several times. Then tie the straw rope slightly at an oblique angle (about 30 degrees) between the direction of the soil ball and the vertical direction. While pulling, use the wooden hammer and masonry prepared in advance, and knock the straw rope while pulling, so that the straw rope is slightly embedded in the soil and tied more firmly. Each straw rope is about 8 cm apart until a soil ball is tied completely.
If the diameter of the soil ball is less than 40 cm, it should be tied with straw rope, which is called "single strand and single shaft"; If the soil ball is large, bind it twice with straw rope in the same direction, which is called "single strand uniaxial"; If the soil ball is very big and the diameter is more than one meter, it must be tied twice with two straw ropes, which is called "double-stranded biaxial". After the longitudinal straw rope is tied, it will be tied firmly at the root of the trunk.
D. Tying the waist rope: For the soil ball with a diameter of more than 50 cm, after the longitudinal tying is completed, a horizontal straw rope should be tied in the middle of the soil ball to protect the soil ball, which is called "tying the waist rope". The method is: another straw rope is tightly wound in the middle of the soil ball for several times, and then connected in series with the straw rope obliquely from top to bottom with vertical and horizontal straw ropes to prevent the waist rope from slipping.
E. Back cover: After tying the waist rope, gently push down the seedlings and tie the ball tightly with a straw bag, which is called "back cover". The method is: first, make a small ditch on one side of the pit (the direction to be pushed down), tie a straw rope at the bottom of the pit, and insert the straw rope in the exposed place at the bottom of the soil ball with a pu bag to cover it tightly. The Almighty pushes the seedlings down in the direction of ditching, and then firmly crosses and binds them to the opposite longitudinal straw ropes with straw ropes on the back.
F. When the soil is too dry and easy to loosen, and it is difficult to ensure the formation of soil balls, the straw rope can be tied horizontally while digging, which is called "beating the inner waist rope" and then wrapped outside the inner waist rope.
G, soil ball after the back cover, should be immediately shipped out of the pit, such as hard soil is not easy to loose tuo, also shall not use a cattail bag.
Seedling transportation
The quality of transportation and follow-up of seedlings is also an important link that affects the survival of tree planting. Practice has proved that "digging, transporting and planting" is the best guarantee for the survival rate of tree planting.
Transportation and follow-up of seedlings: the transportation of seedlings depends on the amount of planting. Before transporting seedlings, we should go through the plant quarantine procedures according to the quantity and variety loaded, and go with the vehicle. After the seedlings are transported to the construction site, they should be planted in time. When loading and unloading seedlings, handle them lightly, so as to avoid damaging seedlings and causing scattered balls. Loading and unloading of seedlings should be carried out in a certain order, and it is not allowed to take them at will. It is forbidden to load and unload the whole vehicle, so as not to damage the roots and trunks of seedlings. Soil balls smaller than 40 cm can be taken out directly, with the trunk in one hand and the ball in the other. If the diameter of the soil ball is more than 50 cm, you can put a board and gently slide the seedlings down; If the diameter is greater than 80 cm, it needs to be lifted and unloaded by crane. When loading soil ball seedlings, the soil ball should be put forward, and the crown of the tree should be put back neatly according to the driving direction of the vehicle. When transporting bare-rooted seedlings for a long distance, the escort personnel should cooperate with the driver on the way, often check whether the tarpaulin is lifted, and transport seedlings for a short distance without rest. Long-distance driving, if necessary, water should be sprayed to wet the roots to keep them moist. When loading the car, it should be placed neatly; After loading, the trunk should be tied tightly and padded to prevent the trunk from being worn. Bare-rooted seedlings must be transported quickly, quickly, on cloudy days, and must be delivered on the same day before planting. The exposure time of bare-rooted seedlings from emergence should not exceed 8 hours. Take good care of the seedlings when unloading, and handle them with care. Bare-rooted seedlings should be taken and placed neatly, and it is not allowed to pull them randomly, let alone push them all over the car. Seedlings that can't be planted that day should be planted. After the seedlings with soil balls are transported to the construction site, they should be placed neatly. When you can't plant it that day, sprinkle water to keep the soil ball wet.
Seedling fixed-point pay-off
On a flat construction site. Construction personnel shall check with the site according to the design drawings, take the coordinate datum point designed in the drawings as the lofting datum point, use flat-panel instruments and grid method, and determine the planting position of plant communities and individual plants according to the scale requirements of the drawings, mark the tree species with wooden stakes, indicate the specifications of tree species and tree pits, draw the range line of tree groups with white plaster, and nail wooden stakes within the scope. Indicate the specifications of several kinds, quantities and pits, and then visually measure the planting point of a single plant. Pay attention to the following points in fixed-point setting-out: a. Tree species, quantity and location should be consistent with the design drawings. B, shrub configuration should be natural, should be fixed according to the principle of organization and coordination of shrubs, avoid by all means dull, avoid exclusion or equidistant planting. When trees encounter obstacles, they should get in touch with the design unit in time and make appropriate adjustments. After the fixed-point pay-off is completed, the acceptance shall be accurate.
Dig a hole in the ground
Before digging a hole, you should know about underground pipelines and hidden objects. The quality of digging a pit has a great influence on the growth and development of plants in the future. The size of the pit should be determined according to the size and soil quality of seedlings and soil balls of different sizes, and generally it should be 20-30 cm larger than the specified root system and soil ball diameter. At the same time, the depth of the pit should be determined according to the root type of the tree species, and the pit should be cylindrical to ensure that the root system is extended and easy to survive when planting. When digging a hole, mark the center of the circle, draw a circle in proportion, and dig vertically down the circumference to a specified depth. Then the bottom of the pit is dug loose and leveled, and it is best to pile a small mound in the center of the bare-rooted seedling pit to facilitate the extension of the root system. After the reverse excavation, insert the fixed-point pile on the mound of the pit for inspection when sowing seedlings. When digging a pit, the topsoil and subsoil should be stacked separately. Because of the high content of organic matter in topsoil, the pit bottom is filled first and the upper part is filled with subsoil for cofferdam. After the land is leveled, dust prevention measures should be taken.
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