How to plant eucalyptus urophylla

Eucalyptus urophylla is an ideal tree species for soil and water conservation. The planting method is as follows:

I. Forest land selection

Choosing afforestation sites is the basis of planting fast-growing and high-yield forests. Choose low hills with deep and fertile soil layers. Sandy soil is the best soil, which requires loose soil and strong permeability, and is most suitable for mechanized farming.

Second, tree species selection

There are many excellent varieties of eucalyptus urophylla, each with its own advantages and disadvantages. Different eucalyptus varieties should be selected according to different site conditions, and different tree species (strains) have different requirements for opposing conditions, especially for soil fertility. Therefore, in order to build a high-yield eucalyptus urophylla forest, we should follow the principle of "suitable land and suitable trees" and choose suitable afforestation trees or varieties according to the situation of afforestation sites, so as to achieve better benefits.

Eucalyptus urophylla U6 is an excellent strain selected from Eucalyptus urophylla seedling forest, which has been widely planted in Guangdong, Guangxi and Hainan provinces. It has the advantages of fast growth, high yield, bacterial wilt resistance, strong wind resistance and strong germination of the second and third generations. The disadvantage is that the fast-growing performance is slightly degraded, which requires high soil fertility and is not tolerant of barren land. It is not suitable for growing in low-lying areas with waterlogging and poor drainage. In the hot and rainy season, if planted too closely, the air permeability of the stand is not good, which is easy to cause dead (commonly known as defoliation) and affect the growth of trees.

? Third, seedling procurement

Improved varieties and strong seedlings are the basis and guarantee for building high-yield forests. In recent years, the market of eucalyptus seedlings has developed rapidly, and there are many eucalyptus nurseries, but the quality of seedlings is uneven. In order to ensure the quality of seedlings, afforestation units and farmers must be cautious when purchasing seedlings. They can consult the local forestry department first and buy seedlings in nurseries with seedling business licenses, and it is best to buy seedlings in eucalyptus seed bases.

Three inspections should be carried out when purchasing eucalyptus clones;

One is to ask whether the mother plant in the cutting nursery is a tissue culture seedling. If it is not a tissue culture seedling, but a cutting seedling instead, don't buy it;

The second is to inquire about the age of the mother plant. Generally, the cutting mother plant is required to be updated every two years. If the cutting mother plant is too old (not updated for more than three years), it is not suitable for purchase. To know how old and young the mother plant is, you can look at the head of the mother plant. Generally, if the head is small and tender, the parent plant is tender and the quality of the seedlings is better. If the tree head is larger, the cuttings will be older, resulting in poor seedlings and poor afforestation effect. Even if the seedlings are cheap, you can't take them.

The third is to check whether the seedlings from the nursery have complete terminal buds, developed roots, healthy and strong, and the seedling height is 18-25 cm. Choosing seedlings with complete terminal buds, developed roots, strong and moderate height has good afforestation effect. Expired superelevation is used for greening, with low survival rate; The seedlings are too small, the roots are underdeveloped and the survival rate of afforestation is low.

Fourth, afforestation measures

(1) refining mountains

Mountain refining is an important process of afforestation, which has a great influence on afforestation effect. Mountain refining can not only harvest plant ash, but also improve soil fertility and kill germs through high temperature. Therefore, in the winter of the year before afforestation, it is necessary to carry out comprehensive mountain refining and clean up the woodland. In mountainous areas with many miscellaneous shrubs and difficult mountain refining, the mountains should be thoroughly refined after "greening", and unburned shrubs and branches should be piled up and burned to prevent termite damage. Mountain smelting should pay special attention to fire safety, and adequate safety measures should be reported for approval before mountain smelting.

(2) Methods and specifications of soil preparation

Soil preparation is one of the key measures to build a high-yield eucalyptus forest. Eucalyptus likes to grow in loose soil, so it is very important to choose the appropriate soil preparation method according to the conditions of afforestation site and loosen the soil as much as possible. There are three main land preparation methods for building high-yield eucalyptus forests:

1, fully reclaimed by machine ploughing. Suitable for gentle slope afforestation land with flat terrain or slope less than 10 degree. Mechanical total reclamation is divided into three steps: first, clean up the miscellaneous shrubs and tree tops on the forest floor; Ploughing the afforestation land again by machinery, and the depth of mechanical ploughing is more than 40 cm; Finally, according to the planting density of afforestation design, planting ditches are opened, with the depth of 40-50 cm and the spacing of 2.5-3 meters, so as to adopt mechanical tending in the future.

2. Land preparation through reclamation. Suitable for gentle slopes. Land preparation by reclamation can fully loosen the soil around the planting area, which is beneficial to the growth of young forests and does not cause soil erosion. The specific method is: use a high-power tractor to fully plow loose soil into strips along the contour line of the hillside, and the width should be suitable for planting two rows of trees. There is an uncultivated area between the mechanized tillage areas to prevent soil erosion, and other land preparation operations are the same as full tillage.

3. Cave reclamation and land consolidation. Suitable for afforestation land with large slope and unsuitable for mechanical farming. By opening holes for soil preparation, it is necessary to clean up the miscellaneous shrubs and tree heads on the forest floor, and then determine the planting holes (points) according to the designed planting density, and open planting holes with the length of 50×50×40 (or 40×40×30) cm, width and depth along the contour line, and leave surface soil containing humus when opening holes, so as to backfill the hole bottom with nutrient-rich surface soil when planting.

After the soil preparation is completed, the soil should be weathered for a period of time before planting. If the filter mud and phosphate fertilizer are used to make afforestation base fertilizer, the base fertilizer can be applied first, and the soil at the edge of the ditch (hole) can be crushed back to about 80% in the hole, and then the ditch (hole) can be filled when planting. If the base fertilizer is chemical fertilizer (such as compound fertilizer), you can fill the ditch (hole) in advance and wait for planting.

(3) Planting density

Reasonable planting density can not only avoid the influence of tree differentiation caused by tree density or natural pruning on individual tree volume, but also avoid soil drought caused by sparse trees and excessive evaporation of bare water in woodland. At the same time, it is necessary to ensure the yield per unit area by ensuring a certain number of plants. Some people think that "the greater the density, the greater the output" and "many kinds can be obtained", which is without scientific basis. Afforestation is too dense, even if 300-400 trees are planted on an acre of land, the young forest will be closed in a few months. Due to poor ventilation and light absorption, trees are prone to illness. At the same time, due to too dense planting, trees begin to shed leaves and dead branches in less than 1 year, which seriously affects the normal growth of trees, often failing to grow trees, with small volume per plant and low yield when cut down. Planting is too sparse, the number of trees per unit area is too small, and the wood output is low. Therefore, it is very important to adopt suitable planting density. When designing the row spacing of afforestation plants, it is advisable to adopt wide rows and narrow plants. The wide row spacing of 2.5-3.0 meters is proved to be beneficial to the growth of trees, and it is convenient for ditching, weeding, loosening soil and topdressing after afforestation or germination, and it is also convenient for cutting operations.

According to years of experience, the row spacing of eucalyptus urophylla U6, hybrid eucalyptus LHI, hybrid eucalyptus Donghai 1 and Donghai No.3 can be 2.5×( 1.6-2) meters (per mu 167- 133 plants). Congo 12 eucalyptus W5 and hybrid eucalyptus Shiling 1 can be planted 185-238 plants per mu, and the plant spacing can be 1.2× 3m (per mu 185 plants), 1× 3m (. The planting density in mountainous areas is slightly higher than that in flat slopes.

(4) base fertilizer

Excellent eucalyptus varieties, because of their fast growth, high yield and large fertilizer demand, it is very important to apply base fertilizer for afforestation. Applying base fertilizer is an important measure to ensure high yield of eucalyptus. Without fertilization, eucalyptus can't grow and high yield can't be achieved. Afforestation base fertilizer should have a reasonable ratio of nitrogen, phosphorus and potassium.

According to the soil conditions in Gaozhou area, phosphorus fertilizer should be used as the main base fertilizer, and nitrogen, phosphorus and potassium fertilizer should be applied together, with remarkable results.

There are five basic fertilizers commonly used:

1, phosphate fertilizer+urea+potassium chloride mixed fertilizer. Through the practice in recent years, the mixed fertilizer method is troublesome, but the cost is low and the effect is good. The specific mixing method is as follows: phosphorus powder: urea: potassium fertilizer = 1: 0.2: 0.3, that is, 100 kg of phosphorus powder is mixed with 20 kg of urea and 30 kg of potassium fertilizer, and 0.5-0.8 kg is applied to each plant after being evenly mixed, and it is evenly mixed with the soil of the planting hole and planted in rainy days.

2. Chicken manure+phosphate fertilizer+carbon safe compound fertilizer. Apply 3 kg of chicken manure+5 Liang of phosphate fertilizer+3 Liang of carbofuran to each plant, and apply it after thorough mixing.

3. Mixed compost of filter mud and phosphate fertilizer. The filter mud from sugar factory is transported to the vicinity of the afforestation site, and it is piled for about 1 month, and then 50 kg of phosphate fertilizer is added to the filter mud according to the wet ton, and it is piled for 7- 10 days. If the filter mud is not fully collected and reused, it will ferment, burn and even burn seedlings. Before planting, apply 8- 10 kg to each plant, spread it evenly along the planting ditch (or hole) and cover it with soil. When planting, apply 1-2 urea to each plant.

4. Import 0.3-0.5 kg of Norwegian compound fertilizer.

5, eucalyptus fertilizer (Batian, Lin Lei eucalyptus fertilizer) 0.5- 1 kg.

No matter what kind of base fertilizer is applied, we should pay attention to the following problems:

First, when applying base fertilizer, the fertilizer should not be in direct contact with the planted seedlings to prevent burns. Fertilize and cover the soil in the planting ditch 20 cm away from the seedling (planting point); You can also dig a deep pit when planting, put the fertilizer at the bottom of the pit, return the mud to 5-8 cm, mix it evenly with the fertilizer, and then plant seedlings in soil separated from the fertilizer;

Second, be careful not to concentrate on fertilization, block fertilizer should be crushed, and the applied fertilizer should be mixed with the surrounding soil to avoid affecting fertilizer efficiency or burning seedling roots;

Third, cover the soil in time after fertilization to prevent nutrient volatilization and reduce fertilizer efficiency.

(5) Planting

Eucalyptus can be planted in Gaozhou area in spring, summer and autumn, but afforestation after rain in spring is the most suitable. At this time, the temperature is not high, the air and soil are moist, and the survival rate of afforestation is high.

Before planting, the ploughed or dug topsoil should be backfilled into the ditch (hole). If soil impurities such as filter mud and phosphate fertilizer are used as base fertilizer, the base fertilizer should be applied to the bottom of the ditch (hole) first, and then returned to the mud. When planting, small holes should be dug in the loose soil of ditches (holes) for planting. If chemical fertilizer (such as compound fertilizer) is used as the base fertilizer, 80% of the soil should be backfilled first, and then after a soaking rain or continuous light rain, holes should be dug in the loose soil along the ditch (hole) and planted while fertilizing.

Some people plant seedlings directly at the bottom of ditches (holes) without backfilling, which is not correct. This will make the land preparation ineffective, and it is easy to cause the seedlings to be soaked and buried after the rainstorm, which is very unfavorable for the growth of trees.

Pay attention to the following links when planting:

1, seedlings from nursery to woodland should be straightened after planting, and can be planted on the mountain after watering. 2. When distributing the seedlings to the planting site, be careful not to throw them around, so as not to lose them. 3. When planting, gently compact the nutrient soil at the root of the seedling, then tear off the film bag and plant the seedling in the field, being careful not to scatter the nutrient soil. If the film bag is not torn off, the root system of the seedling is blocked by the film, which can not absorb water and nutrients, and the survival rate of afforestation is low; Even if it survives, it will vortex roots and affect the growth of young trees. 4. When planting seedlings, return the soil to cover the base of seedlings for 2-3 cm, and compact the soil around young trees with hands or feet to make the roots of seedlings fully contact with the soil to absorb water and nutrients in the soil. 5. If afforestation is carried out in sunny days or when soil moisture is insufficient, water should be poured on the roots after planting to ensure the survival of seedlings.

(6) Replanting seedlings

If you plant trees in the field after rain, the survival rate can generally reach more than 95%, and afforestation can be completed at one time without replanting. But when the survival rate is low in some places or in general, it is necessary to replant seedlings.

Transplant seedlings as soon as possible. After afforestation for half a month, it is necessary to check the survival of seedlings in time, and replenish seedlings in time if missing or dead seedlings are found. If the seedlings are replanted every two or three months, even if they survive, it is difficult to become useful. The reason is that eucalyptus grows fast, and the young trees planted in the early stage are quickly covered, which affects the growth of seedlings replanted in the later stage.

Verb (abbreviation of verb) tending management

Tending management is another important link of fast-growing and high-yield eucalyptus forest, and it is also a necessary measure to build fast-growing and high-yield eucalyptus forest. The main contents of young forest tending are topdressing, loosening soil and weeding. Two years before afforestation, usually once a year 1-2 times. For afforestation in spring, the first topdressing and tending should be carried out when the young trees grow to a height above 1 m around September of that year. The second topdressing and tending will be carried out in April-May of the following year. When conditions permit, topdressing will be carried out in the third year.

Each topdressing and tending should be carried out after rain and when the soil is wet. When topdressing, dig a small hole between two small trees for fertilization, and return the soil to cover the fertilizer in time after fertilization. It is better to cooperate with weeding and soil improvement when fertilizing.

The principle of topdressing is to highlight nitrogen fertilizer and combine nitrogen, phosphorus and potassium.

There are two kinds of fertilizers commonly used for topdressing and tending of eucalyptus high-yield forests:

(1) Phosphate fertilizer+urea+potassium chloride compound fertilizer: the first topdressing is urea 1-2+potassium chloride 0.5- 1 2 per plant. For the second and third topdressing, each plant was applied with 3 Liang of phosphate fertilizer+2 Liang of urea+0.5- 1 2 of potassium chloride.

(2) Compound fertilizer: 2-3 Liang of compound fertilizer +65438+ 0-2 Liang of urea are applied to each plant.

When topdressing, pay attention to mixing several fertilizers in proportion before applying.

Six, eucalyptus budding forest tending management

Eucalyptus has a strong ability of germination and regeneration, and it can be cut down and used for 2-3 times once planted. But only cutting, not tending, the output of trees is obviously not as good as that of the first generation. By strengthening the management of the budding forest, the second generation or even the third generation of eucalyptus budding forest can still obtain high yield.

Tending of eucalyptus budding forest mainly focuses on loosening soil, fixing plants and topdressing:

(1) scarify the soil

After the trees are cut down, ditch the soil before the tree heads sprout. It is best to use a high-power tractor with three iron hooks to loosen the soil along the line, with a depth of about 40 cm. The function of loosening soil: first, loosening soil to release nutrients and fertility, which is convenient for trees to absorb; Second, it is beneficial to the respiration and ventilation of tree roots; The third is to hook off the old roots with poor absorption ability, so that more new fibrous roots with strong absorption ability can grow on the tree head, which is beneficial to the growth of trees.

(2) Fixed factory

Eucalyptus has strong germination ability. After logging, a tree head can generally sprout six or seven buds, up to a dozen or twenty. There are many sprouting strips, which compete for nutrient space and soil nutrients, which is not conducive to budding forests. Therefore, the budding forest should be thinned and fixed in time.

In the practice of planting: after cutting down trees, when the shoot length at the head of the tree is about 1.5m, and the differentiation is obvious, according to the principle of "removing the weak and keeping the strong, removing the dense and keeping the sparse, and keeping the reasonable spacing between plants", select and keep the 1-2 dominant plant with vigorous growth, obvious top advantage and straight stem shape, and all the other shoots are cut off from the base.

Some rangers are unwilling to cut off too many budding strips after cutting, or even if they cut off a part, they still keep more than 3-4 strips. The result is that although there are many sprout strips, they grow slender and have no volume, and the wood output is lower than that of trees when they are cut down.

(3) Topdressing

After loosening the soil and fixing the seedlings, the budding forest must be topdressing in time.

The method of topdressing is: several kinds of chemical fertilizers are evenly mixed according to the dosage and applied into the ditch (hole), and then covered with soil. Top dressing for the first time, applying 5-6 liang of phosphate fertilizer +65438+ 0-2 liang of urea+0.5- 1 liang of potassium chloride to each plant; For the second and third topdressing, each plant was applied with 3 Liang of phosphate fertilizer+2 Liang of urea+0.5- 1 2 of potassium chloride. If compound fertilizer is used for topdressing, 3-4 Liang of compound fertilizer +65438+ 0-2 Liang of urea can be applied to each plant each time.

Seven, the main diseases and insect pests of eucalyptus and their control

The main pests and diseases of eucalyptus are bacterial wilt, scorch (commonly known as defoliation), stem rot of eucalyptus seedlings, eucalyptus moths, termites, scarabs and so on.

(1) Bacterial wilt: At present, there is no effective method to control bacterial wilt. Control measures: mainly select strains with strong disease resistance for afforestation.

(2) scorch disease (commonly known as defoliation): This disease is caused by high temperature and high humidity, which can cause eucalyptus to die in severe cases, especially when eucalyptus urophylla and its clones encounter high temperature and rainy weather for six or seven consecutive days, and some places with low terrain, poor drainage, high afforestation density and poor forest permeability are prone to disease. Prevention and control measures: Choose land with good drainage for afforestation, and make drainage ditches in low-lying areas. The planting density should be appropriate, not too dense.

(3) Stem rot of eucalyptus seedlings: it is a disease of eucalyptus seedlings. When it happens, the stems of eucalyptus seedlings rot and die gradually. Control measures: chlorothalonil or chlorothalonil or Bordeaux solution should be used at seedling stage or before seedlings leave the nursery, and then sprayed after diluted to the concentration.

(4) Eucalyptus leaf roller moth: it harms young leaves of Eucalyptus from April to August every year, damages young branches and terminal buds, makes young trees wither and affects growth. Control measures: (1) Manual kneading. When you see the tender leaves of a small tree with curly leaves, crush the larvae in the curly leaves with your hands. (2) Pesticide spraying. Spray with trichlorfon 600 times solution and a small amount of kerosene or dimethoate 1000 times solution or pyrethroid (according to the concentration).

(5) Termites: mainly harm the bark of eucalyptus trunk and seriously affect the growth of trees. Prevention and control measures: (1) trapping and killing. Bury with bagasse, sugar, etc. Lure termites to concentrate and then poison them with pesticides; (2) Drug-driven. Metarhizium anisopliae produced by Guangdong Academy of Forestry has a good effect. The use method is to prepare Metarhizium anisopliae into liquid medicine according to the instructions, soak the afforestation seedlings in the liquid medicine, and then take off the afforestation, which can effectively control termites; (3) Internal inhalation poisoning. Applying carbofuran to the soil around small trees will poison termites. Carbofuran can be applied alone or together with other base fertilizers.

(6) Scarab: Larvae (commonly known as chicken mite) harms the roots of young trees, especially some cultivated land such as sugarcane fields and sweet potato fields, with many larvae and serious harm. Adults harm the leaves of young trees. Prevention and control measures: (1) During afforestation, 4-5 kg of trichlorfon powder (or 2.5 kg of terbutyphosphine) should be evenly scattered in planting holes to drive away and kill turtle larvae. (2) The pesticides trichlorfon and methamidophos are diluted into 600-800 times solution and sprayed on the leaves, which can effectively kill adults.