CN104737735B - A method for ecological greening of coastal saline-alkali land by using original soil planting - Google Patents

Abstract

The invention provides a technique for ecological afforestation of coastal saline-alkali land by using raw soil planting. The technology of the present invention is to use the hybrid tree species, which is a multi-resistant, fast-growing, high-yield, high-quality ecological and economic forest tree species, combined with a series of measures such as reasonable planting land selection, land arrangement, seedling preparation, water and fertilizer management, disease and insect pest control, plastic pruning, etc. , so that the survival and growth of the hybrid tree can be guaranteed, thus successfully establishing a greening system for the hybrid tree in the coastal saline-alkali land. The technology of the invention does not need to take too many engineering measures on the soil, and can greatly reduce the cost of greening projects. Therefore, the technology of the invention has very good application prospects in greening saline-alkali lands such as coastal saline lands and coastal tidal flats.

Description

A method for ecological greening of coastal saline-alkali land by using original soil planting

technical field

The invention belongs to the field of environmental protection, and in particular relates to a method for establishing a greening system of coastal saline-alkali land and/or coastal tidal flat saline-alkali land.

Background technique

At present, the greening technologies in coastal saline-alkali land and/or coastal tidal flat saline-alkali land ecological greening engineering mainly include halophyte greening, original soil improvement greening and alien soil greening.

Halophyte greening technology is the use of halophyte afforestation, which is an important method of biological measures to improve saline-alkali land. Halophytes are natural flora on saline soils, which can grow normally and complete their life cycle on saline soils, and are pioneer plants in saline-alkali soils. Using halophytes to green saline-alkali soil not only embodies the principle of ecological adaptability, but also saves a lot of natural and social resources, which meets the needs of ecological greening of coastal saline-alkali land. The main halophyte communities include Tamarix community, Siberia Nitraria community, Suaeda salsa community and Phragmites reed community. There are three types of halophytes: halophytes, halophytes, and halophytes. Among them, salt-accumulating plants can tolerate high-salt concentration saline soil, but most of them are herbs and single species, which are not suitable for large-scale application in seaside saline-alkali landscaping ecological greening; salt-secreting plants can absorb too much salt from saline soil, But it does not accumulate in the body, but secretes the absorbed salt through the salt gland cells densely covered on the surface of stems and leaves, and the secreted crystallized salt is diffused by wind and rain on the surface of the meridian and leaves, so it cannot be used to improve seaside salt Alkaline soil: Salt-repelling plants, also known as salt-resistant plants, can grow normally on saline-alkali soil, but they also cannot absorb salt in the soil. Therefore, the technology of using halophytes to green saline-alkali soil has certain advantages, but the single species of plants also has shortcomings.

The guest soil greening technology is a greening technology commonly used in coastal saline-alkali soil greening, which has the characteristics of good and fast greening effect. In order to prevent secondary salinization of alien soil, it is necessary to take measures to control salt. For partial soil replacement and greening, the comprehensive measures of foreign soil + salt-separating dark layer can be adopted; for comprehensive soil replacement, the comprehensive measures of foreign soil + salt-separating dark layer + underground pipe drainage are suitable. From this point of view, the initial investment cost of guest soil greening technology is large, and the later maintenance cost is high. It increases the financial investment of coastal saline-alkali land greening, which is not suitable for large-scale promotion.

The original soil improvement and greening technology mainly includes technical measures such as building terraces, irrigation with water and salt, cushioning isolation layers, applying organic fertilizers, and planting garden plants with strong salt tolerance. The coastal saline-alkali soil has high salinity, barrenness and poor structure. Local original soil improvement and greening can take comprehensive measures of fertilization and soil improvement + salt barrier dark layer + irrigation and salt spraying; comprehensive original soil improvement and greening can take comprehensive measures of fertilization and soil improvement + salt barrier dark layer + hidden pipe drainage + irrigation and salt spraying. Original soil improvement greening is ecological and environmentally friendly, but the improvement greening time is long, and the initial landscape effect is poor. The use of this technology should be planned and arranged reasonably.

Contents of the invention

An object of the present invention is to provide a method for ecological greening of coastal saline-alkali land and/or coastal tidal flat saline-alkali land by planting in original soil.

An object of the present invention is to provide a method for ecological greening of coastal saline-alkali land and/or coastal tidal flat saline-alkali land, comprising the steps of: planting a hybrid tree on coastal saline-alkali land and/or coastal tidal flat saline-alkali land with a salt content of less than 1%, so that Coastal saline-alkali land and/or tidal flat saline-alkali land are greened.

In the method, when the salt content of the coastal saline-alkali land and/or coastal tidal flat saline-alkali land is below 1%, hybrid trees can be directly planted to realize ecological greening of the saline-alkali land; when the coastal saline-alkali land and /or when the salt content of coastal beach saline-alkali land is 1%-1.5%, can make the salt content of described saline-alkali land reach below 1% through the following land consolidation process of the present invention earlier, after planting hybrid tree, also can Realize the ecological greening of saline-alkali land with a salt content of 1%-1.5%.

When the salt content of the coastal saline-alkali land and/or coastal tidal flats is 1%-1.5%, before the planting of hybrid mulberry trees, it is necessary to carry out land consolidation, so that the coastal saline-alkali land and/or coastal tidal flats after land consolidation The salt content of saline-alkali land is below 1%, and the method for described land consolidation comprises the following steps 1)-4):

1) A road with a length consistent with the length of the rectangular land and a width of 3-5m is set in the center of the entire rectangular land, and the road divides the rectangular land after subtracting the area of the road into two small pieces of equal area. Rectangular land; On the two small rectangular lands, open a plurality of drains parallel to the wide sides of the small rectangular lands respectively, the top width of the ditch is 3m, the depth of the ditch is 1-2m, and the length of the ditch is the same as that of the small rectangular lands. The width of the rectangular land is consistent, and the wall of the ditch should be inclined at an angle of 45 degrees to the outside of the ditch; the multiple ditches on each small rectangular land communicate with the outside of the whole piece of rectangular land and communicate with each other; The drainage ditch divides the small rectangular land into multiple independent strips and terraces with equal areas respectively; the width of the strips and terraces is 8-12m, and the length is consistent with the length of the small rectangular land;

On the ditch wall, slope protection treatment is also required, and the slope protection treatment process includes using an excavator or a shovel to pat the ditch surface tightly and compact it to meet the requirements;

Preferably, a road with a length consistent with the length of the rectangular land and a width of 4m is set in the center of the entire rectangular land, and the road divides the rectangular land after subtracting the area of the road into two small rectangles with equal areas Land; on the two small rectangular lands, open a plurality of drains parallel to the broadsides of the small rectangular lands respectively, the width of the top of the ditch is 3m, the depth of the ditch is 1.5m, and the length of the ditch is the same as that of the small rectangular lands. The width of the ditch is the same, and the ditch wall should be inclined at an angle of 45 degrees to the outside of the ditch; the multiple drainage ditches on each of the small rectangular lands communicate with the outside of the entire rectangular land and communicate with each other; the multiple drainage ditches The ditch divides the small rectangular land into multiple independent strips and terraces with equal areas respectively; the width of the strips and terraces is 10m, and the length is consistent with the length of the small rectangular land;

2) base fertilizer application, described base fertilizer application comprises excavating on each bar, platform fields and a plurality of ditches parallel to bar, platform field long sides for applying base fertilizer, 20 ± 3 centimeters of ditch width, preferably 20 centimeters of ditch width, The ditch depth is 30 ± 5 cm, the ditch depth is preferably 30 cm, and the ditch distance is 1 m. In the ditch, 3000 kg/mu of organic fertilizer is applied, and 50 kg/mu of NPK compound fertilizer is added at the same time; the ditch is filled with soil and placed for 15 days. decomposed organic fertilizer;

3) Build the irrigation system: combine the seedling belts to be planted, and set up and lay suitable drip irrigation belts;

After the laying of the drip irrigation belt is completed, the whole ground is irrigated once to permeate the water, and the salt in the soil is washed to further reduce the salt content of the soil and improve the survival rate of the seedlings;

The process of applying base fertilizer is completed before the laying of the drip irrigation belt is completed and once permeable;

The nursery stock belt that prepares for field planting is a ridge;

4) Ridging: In each of the strips and terraces, along the direction parallel to the long sides of the strips and terraces, make multiple high ridges with a width of 50 centimeters and a height of 20 centimeters. The distance between them is 50 cm, and the distance is used as a walkway; a planting furrow of 20 cm × 20 cm is excavated in the center of the high ridge; In the field, design the drainage ditches parallel to the broadsides of the strips and terraces at intervals of 10m respectively. The top width of the drainage ditches is 50 centimeters, 20 centimeters deep, and the ditch length is the same as the width of the strips and terraces. Consistent, the ditch wall should be inclined at an angle of 45 degrees to the outside of the ditch, and slope protection should be done well;

The ridging is completed after the laying of the drip irrigation belt is completed and once permeable;

The construction of the irrigation system and the ridging can be carried out simultaneously;

5) Plant the hybrid mulberry tree in the planting ditch described in step 4).

The slope protection treatment is specifically to use an excavator or a shovel to pat and compact the surface of the ditch to meet the requirements.

In the method, before planting the hybrid tree, seedlings need to be hardened, and the hardening includes: using a sunshade net to build a seedling hardening shed about two meters high, and placing the tissue cultured seedlings at a distance of 0-5 cm. In the shed, ventilate in a timely manner in the morning and evening. When the sun is stronger than 50,000 lux and the temperature is higher than 35 degrees on a sunny day, put down the sunshade net to cool down. Depending on the specific situation and combined with water and fertilizer management, gradually extend the ventilation time and light time. Generally, after 10-15 days Over time, strong seedlings can be cultivated.

The specific water and fertilizer management is to add water after standing for 3-4 days, and the amount of water replenishment is determined according to the degree of water shortage.

The gradual extension of ventilation time is specifically that the first ventilation time is half an hour, and then increases by half an hour every day until transplanting.

In the method, the conditions for planting hybrid trees include the following 1)-5):

1) It can be planted in months when the minimum temperature is higher than 10°C; it is preferred to plant in the first half of the year in northern my country;

2) The planting density is selected as 1m×1m;

3) Avoid planting at noon when the sun is strong; planting in the evening is preferred;

4) The planting depth should not exceed 20 cm;

5) Fill the planting water in time after planting;

The planting of the hybrid tree is specifically planting the above-mentioned strong seedlings cultivated after 10-15 days.

In the method, after planting the hybrid mulberry tree, irrigation and/or fertilization are required; the planting of the hybrid mulberry tree is specifically planting the above-mentioned strong seedlings cultivated through 10-15 days; the irrigation includes : water every other day in the first week after the planting of the strong seedlings, and water twice in the second week at least; Watering; after the seedlings are quite long, before winter, water the frozen water in a timely manner; the main points of the watering include: each watering should be watered in a sufficient amount, and do not water halfway;

The timely pouring of frozen water specifically refers to pouring frozen water before the soil is frozen from late October to early November.

The fertilization includes: after the seedlings have survived for 2 months, topdressing high-nitrogen compound fertilizer once at a rate of 0.2kg/plant during the peak growth season, and after the leaves fall in autumn, straws such as rice and corn can be applied all over the ground to cover the ground.

In the method, after planting the hybrid mulberry tree, it is also necessary to carry out pest control, pruning and/or overwintering management and protection;

The control of diseases and insect pests includes: spraying 2000-3000 times liquid of 1.8% of the insecticide gram EC to prevent and control aphids and/or mites; before the hybrid tree is planted, the insecticide can be mixed with the soil to prevent and control Moth pests; after planting, if moth pests are found, the emulsion insecticide can be applied with water for control; the insecticide is a common insecticide for preventing and controlling soil-borne pests on the market;

The shaping pruning includes: when the hybrid tree sapling grows to 80 centimeters, the redundant branches of the sapling can be thinned out, and about 5 branches with better shape at the top are kept, and similar pruning and branching is carried out to the sapling branches every month in the future. Gradually increase the trunk height of the tree body, do not prematurely, excessive pruning, when the tree body grows to about 3m, it can be fixed dry, and then transplant the 2-year-old seedlings after the fixed dry;

The overwintering management and protection include: if the lowest temperature in the planting place is lower than -10°C or extreme weather lower than -10°C may occur, appropriate cold protection measures must be taken for the seedlings, and the cold protection measures include any of the following 1)-5) One said:

1) Appropriate pruning is carried out to seedlings;

2) Remove weeds, plow the land, cultivate soil at the base of the tree roots, and pour antifreeze water;

3) Bind the trunk with rice straw, straw rope, etc. to keep warm and keep out the cold. In colder areas, a layer of plastic sheeting needs to be added outside;

4) Cover the ground with crop straw or cover the tree hole with plastic film;

5) When conditions permit in some places where the planting of seedlings is relatively concentrated, grass thatch can be used to build a windshield or a plastic sheet can be used to build a greenhouse without affecting the viewing effect.

Another object of the present invention is to provide the application of any of the methods described above in the ecological greening of coastal saline-alkali land and/or coastal tidal flat saline-alkali land.

Aiming at the shortcomings in the current ecological greening technology of coastal saline-alkali land and/or coastal tidal flat saline-alkali land, the present invention provides a technology for ecological greening of coastal saline-alkali land by using original soil planting. The technology of the present invention mainly utilizes hybrid tree species, which is a multi-resistant, fast-growing, high-yield, high-quality ecological and economic forest tree species, combined with a series of reasonable planting land selection, land arrangement, seedling preparation, water and fertilizer management, disease and insect pest control, plastic pruning, etc. Simple engineering measures and plant cultivation management techniques ensure the survival and growth of the hybrid tree, thus successfully establishing the hybrid tree greening system in coastal saline-alkali land. The technology of the invention does not require excessive engineering measures on the soil, and can greatly reduce the cost of greening projects. Therefore, the technology of the present invention has very good application prospects in saline-alkali lands such as afforesting coastal saline-alkali lands and coastal tidal flats.

The present invention has carried out a number of planting experiments continuously in Caofeidian, Hebei and Dagang oil field test sites in Tianjin through the above-mentioned method, and has accumulated a large amount of experience in planting hybrid mulberry trees in saline-alkali lands such as coastal saline-alkali lands and coastal tidal flats. At present, a seedling base has been established in the Tianjin Dagang Oilfield Test Base, and a large number of hybrid tree seedlings that can be used for saline-alkali landscaping have been cultivated, and a certain number of seedlings have been reserved for larger-scale planting tests and further promotion.

Description of drawings

Figure 1 shows the effect of soil salinity on the survival rate of hybrid mulberry trees.

Figure 2 is a schematic diagram of the design of the planting strips and terraces.

Figure 3 is a schematic diagram of the design of the ditch for applying base fertilizer on each bar and terrace.

Fig. 4 is the design schematic diagram of planting ridges and rows of small ditches on each bar and terrace.

detailed description

The methods described in the following examples are conventional methods unless otherwise specified.

The equipment, utensils, machinery, fertilizers or pesticides used in the following examples can be obtained from commercial sources unless otherwise specified.

The hybrid mulberry tree used in the following examples was bred by the mulberry tree breeding base of the Institute of Botany, Chinese Academy of Sciences, and the public can purchase it from Zhongke Conceive (Beijing) Forestry Technology Co., Ltd.

Embodiment 1. realizes the ecological afforestation of seaside saline-alkali land and/or coastal tidal flat saline-alkali land by original soil planting

(1) Selection of planting seedlings and land selection

1. Selection of planting seedlings

In 2012, a comparative experiment was carried out on the growth of hybrid mulberry and white wax after planting in saline-alkali soil in the Dagang oil area of Tianjin. Station, oil company park and Hong Kong lion living area and other experimental sites planted hybrid mulberry and white wax, and compared the growth in terms of plant height and stem thickness. See Table 1 for the relevant data measured by comparing the growth of hybrid mulberry and white wax.

Table 1

The results in Table 1 show that the hybrid mulberry tree is a fast-growing tree species, and its annual growth is very large under the condition of sufficient water and fertilizer supply.

2. Analysis of the influence of salt content in the soil on the survival rate of hybrid mulberry trees

The Caofeidian test site in Tangshan, Hebei is a high-saline sandy soil formed by sand blowing, with a distinct salt gradient distribution, and the salt content gradually increases with the terrain from high to low. Since the root system of the hybrid tree has certain requirements on the permeability of the soil, it is advisable to choose a plot with loose soil and high dry terrain for planting. According to the salt-tolerant characteristics of hybrid mulberry, 4 kinds of soils with different salinity were set, and the original soil planting mode was adopted. The hybrid mulberry container seedlings were planted in the experimental site in mid-June 2010, and field sampling surveys were carried out every month. .

Figure 1 is the analysis result of the influence of the salt content in the soil on the survival rate of the hybrid mulberry tree. The results in Figure 1 show that when the salt content is below 1%, the survival of the hybrid mulberry tree in the Caofeidian test site is good, and can be stabilized at more than 95%, and the growth is better than that in the high-salt area, and the degree of survival after survival is high; When the salt content is higher than between 1% and 1.5%, after two weeks of adaptation period, it begins to be affected by salt damage, and the phenomenon of continuous dead seedlings appears, and the survival rate is not guaranteed; when the salt content is between 1.5% and 3 % between or higher than 3%, the saplings are difficult to survive, and the survival rate is lower than 20%. Under the soil conditions of this degree, hybrid mulberry trees cannot be planted in the original soil.

3. Land selection

When selecting the actual land for cultivation in production, the salinity content of the land should be measured and analyzed in advance, and the local environment should be carefully considered to prevent changes in land salinity caused by changes in the surrounding environment and cause losses to production. The specific criteria for land selection are as follows:

1) It is advisable to choose loose soil and high dry land for planting;

2) The soil salinity should not be higher than 1%, in order to maintain a good survival rate of the hybrid mulberry tree.

For other coastal saline-alkali lands that do not meet the above two standards, the following simple land consolidation can ensure a relatively high survival rate of hybrid mulberry trees and reduce the cost of greening. The coastal saline-alkali land that meets the above standards will have better plant growth through the following simple land consolidation.

(2) Land consolidation

1. Building strips, terraces, drainage systems and land leveling

The work of land consolidation mainly includes the construction of strips, terraces, drainage system and land leveling, and the three tasks are carried out at the same time. Ditching a large piece of land to make a certain area of independent strips and terraces raises the terrain, facilitates drainage and salt leaching, and reduces soil salinity.

Taking the rectangular land with a length of 49m and a width of 44m as an example, it is convenient to explain the design of strips, terraces and drainage systems on each piece of such rectangular land:

As shown in Figure 2, a road with a length consistent with the length of the rectangular land and a width of 4m is set in the center of the rectangular land with a length of 49m and a width of 44m, and the road divides the rectangular land after subtracting the area of the road into Two small rectangular pieces of land of equal size.

On the two small rectangular lands, open a plurality of drains parallel to the wide sides of the small rectangular lands, the width of the top of the ditch is 3m ± 30 cm, the depth of the ditch is 1.5 m ± 20 cm, and the length of the ditch is the same as the width of the small rectangular land. The width of the small rectangular land is the same, and the ditch wall should be inclined at an angle of 45 degrees to reduce the speed of water discharge, and the slope protection should be done well, that is, use an excavator or a shovel to pat the ditch surface tightly and compact it. To meet the requirements, reduce the damage of running water to the strip field structure; the plurality of drainage ditches on each small rectangular land communicate with the outside of the entire rectangular land and communicate with each other, so that the drainage is not smooth when the flood season comes, causing waterlogging.

The plurality of drainage ditches divide the small rectangular land into a plurality of independent strips and terraces with the same area respectively. The width of the strips and terraces is 10m and the length is 20m.

The land preparation mode of strips and terraces artificially changed the original topography and landform, making the planting land high and dry; changed the structure of the soil, enhanced the permeability of the soil, and formed a good drainage system while preparing the land; combined The following reasonable irrigation system settings can effectively improve the soil environment of saline-alkali land, which is conducive to the survival and growth of hybrid mulberry trees.

2. Apply base fertilizer

Another characteristic of saline-alkali land is that the nutrient content in the soil is low, and due to the effect of saline-alkali, the ability of crops to absorb nutrients will also be reduced. Insufficient nutrients affect crop growth, reduce yield and economic value. Therefore, as a greening tree species and economic crop, hybrid mulberry is planted on saline-alkali soil, and it is necessary to improve the nutritional status of the soil in saline-alkali soil, ensure the nutrient supply of saplings, and promote the growth of trees. An effective way is to apply organic fertilizers on saline-alkali soil.

As shown in Fig. 3, excavate on each bar, terrace field and bar, a plurality of ditches that are used for applying base fertilizer parallel to the long sides of the terrace field, the ditch width is 20 ± 3 centimeters, deep 30 ± 5 centimeters, and the ditch distance is 1m. Apply 3000 kg/mu of organic fertilizer in the ditch, and add 50 kg/mu of NPK compound fertilizer at the same time. Go back to the soil and fill the ditch, let it stand for 15 days, let the organic fertilizer rot, and set it aside. The above-mentioned base fertilizer application process is completed before the laying of the drip irrigation belt is completed and once permeable.

3. Build irrigation system

The design of the irrigation system will be completed before the seedlings are planted, and the drip irrigation belt that is suitable for laying in conjunction with the nursery stock belts that are ready to be planted (the nursery stock belts that are ready to be planted is the ridge in the following step 4), the drip irrigation system of unified management can significantly reduce The labor requirement for irrigation can reduce the cost of cultivation in the long run. After the drip irrigation belt is laid, the whole ground is irrigated once to permeate the water to wash the salt in the soil, further reduce the salt content of the soil, and improve the survival rate of seedlings.

4. Ridging

After the drip irrigation belt is laid and filled with water once, the ridges will be formed. Figure 4 shows the layout of ridges and rows of small ditches in each bar and terrace.

Before planting hybrid mulberry tree, in each bar, terrace, along the direction parallel with bar, terrace long side, do a plurality of wide 50 centimetres, the high ridge of 20 centimetres, i.e. planting ridge, described high ridge and The spacing between the high ridges is 50 cm, which can be used as a walkway.

In order to prevent the ridges from being too long during the rainy season, the rainwater will scour the strip fields excessively, causing soil erosion and destroying the structure of the strip fields. The ridges cannot be designed to be too long. The wide-side parallel drainage ditches of strips and terraces are convenient for scattered drainage. The top of the drainage ditches is 50 cm wide and 20 centimeters deep, and the length of the ditch is consistent with the width of the strips and terraces. The angle of inclination to the outside of the ditch is 45 degrees, and the slope protection treatment is done well, that is, the surface of the ditch is patted tightly with an excavator or a shovel and compacted to meet the requirements.

5. Effect of land consolidation on the growth of hybrid tree

Carried out the following comparison test on the coastal saline-alkali land of Caofeidian, Hebei Province with a salt content of 1% to 1.5%. On the land without above-mentioned land consolidation, after planting saline-alkali land greening tree species (other conditions are the same), the results of the comparative experiment of tree growth show: the survival rate of hybrid tree is more than 80% after the above-mentioned land consolidation; After land consolidation, the survival rate of hybrid trees is only below 0.1%.

The root system of the hybrid tree has certain requirements on the permeability of the soil. The hybrid tree is planted in low-lying and poorly drained areas, because waterlogging is prone to occur in such areas, and the roots of the hybrid tree will be soaked in water. rot, resulting in the death of the plant. The test site is selected as a low-lying, poorly drained area to carry out the same implementation process, and the plant death rate is above 90%.

(3) seedling hardening

Most of the hybrid mulberry trees for planting are about one-month-old tissue culture seedlings from the solar greenhouse. If they are directly planted in saline-alkali soil, they will inevitably slow down the seedlings, grow slowly, and have a low survival rate. A key measure of the tree. Use sunshade nets to build a seedling hardening shed about two meters high, place the tissue cultured seedlings in the shed at a distance of 0-5 cm, and ventilate in a timely manner in the morning and evening. 35 degrees) Put down the sunshade net to cool down, combine water and fertilizer management according to the specific situation (replenish water after 3 to 4 days, the amount of water replenishment is determined according to the degree of water shortage), and gradually extend the ventilation and light time (the first ventilation time is half an hour, and increase every day thereafter. half an hour until transplanting), generally through the time of 10-15 days, strong seedlings can be cultivated, and they can be planted in time (the strong seedlings grow normally, and the seedlings without wilting and other performances can be planted).

(4) Colonization

The planting period of hybrid mulberry is longer, and it can be planted in the months when the lowest temperature is higher than 10℃ in North China. Planting work in Tianjin and Tangshan areas is generally completed from May to September. However, if you choose to plant in the first half of the year, the survival rate of the seedlings will be more guaranteed after a long period of growth, and they can produce some output in the same year.

It is advisable to select 1m × 1m for the hybrid tree planting density of the young stage (that is, the strong seedlings that grow for about 10-15 days). This can make full use of the land under the premise of ensuring the nutrient supply of the tree body. The time selection should avoid planting at noon when the sun is strong, and it is best to choose it every evening. When planting, first remove the nutrient bowl of the seedlings, and try to ensure that the root system is intact and does not disperse. The planting depth should not be too deep, and the depth should not exceed 20 cm. After planting, fill the planting water in time.

(5) Water and fertilizer management

In order to detect the effect of water and fertilizer management on the growth of hybrid mulberry tree, a detection experiment was carried out. Four treatments were set up in the experiment, and each treatment had three repetitions: ck was the control group, no watering and no fertilization; treatment I, watering and fertilization; treatment II, fertilization but no watering; treatment III, watering and no fertilization.

The watering of the treatment Ⅰ and treatment Ⅲ is irrigation, which is carried out according to the following standards: after the seedlings are planted, it takes about 2 weeks to slow down the seedling stage, during which water management should be strengthened. Water, water at least twice a week. After the seedlings survive, water them according to the drought conditions on the ground, usually once a week. After entering the rainy season, you can not water them. After the seedlings are quite long, before winter, water the frozen water in time to facilitate the safe wintering of the seedlings. Key points for watering: water in sufficient amounts each time, and do not water in half. The timely pouring of frozen water specifically refers to pouring frozen water before the soil freezes in late October to early November. Watering too early will not only delay the trees from entering the dormancy period, but also harden the soil. If watering is too late, it is prone to frost damage.

The fertilization of the treatment I and treatment II is carried out according to the following standards: hybrid mulberry trees generally do not need to be fertilized, but if they are used as economic tree species or seedlings for greening, reasonable topdressing is also required to ensure economic yield. After the seedlings have survived for 2 months, the high-nitrogen compound fertilizer can be topdressed once at 0.2kg/plant during the peak growth season to ensure sufficient nutrient supply for the tree. After the leaves fall in autumn, straws such as rice and corn can be applied to the whole ground to cover the ground, which can not only provide fertilizer reserves for the growth of saplings in the coming year, but also play a role in preventing cold and moisturizing and preventing salt return in spring.

The other growth environments and conditions of the four treatment groups were basically the same. When growing for 68 days, the growth of the hybrid mulberry tree was counted from the aspects of plant height, number of leaves, crown width, diameter, and number of branches. The statistical results are shown in Table 2. The data in Table 2 were collected from Tangshan, Hebei, and the experiment year was 2010.

Table 2

The results in Table 2 show that all statistics in treatment Ⅰ are higher than those in the ck control group, and there is a big difference in the growth of the two groups, which proves that water and fertilizer have a significant impact on the growth of hybrid mulberry trees, and sufficient water and fertilizer supply can significantly enhance the growth of saplings. growth.

In Table 2, the statistical data of treatment group I are generally higher than those of treatment group II, which proves that watering has a significant impact on the growth of hybrid mulberry trees. The impact of water on the growth of saplings mainly includes two aspects: on the one hand, daily watering management meets the water supply necessary for plant growth, which directly promotes the growth of plants; The washing effect reduces the salt content of the soil, which can be reduced by 0.3%, so that the degree of salt stress in the process of plant growth is reduced, and even the effect of relieving salt damage is achieved, which is beneficial to plant growth.

In Table 2, the statistical data of treatment group I are generally higher than those of treatment group III, which proves that fertilization has a significant impact on the growth of hybrid mulberry trees. In the process of planting crops, fertilization is a very important task, which is even more important in the cultivation of saline-alkali soil. In the experiment of planting hybrid trees on saline-alkali soil, fertilization can not only promote the growth of plants, but also play a role in the survival of seedlings. Great effect.

(6) Pest control, pruning and overwintering management and protection

There are few diseases and insect pests of hybrid mulberry trees. After investigations and experiments in recent years, no obvious diseases have been found to affect hybrid mulberry trees. Due to the special smell of hybrid mulberry trees, most pests are not easy to breed, which reduces the cost of later management of trees. Pests rarely occur in hybrid mulberry trees in general years, and in years when plant diseases and insect pests break out intensively, there are mainly aphids and mites, which can be controlled by spraying 2000-3000 times of worm gram EC with a volume percentage of 1.8%; in addition, moth larvae are harmful to hybrid mulberry trees. The roots of saplings and saplings will cause serious damage, and most of the insecticides available on the market to control soil-borne pests are effective against such pests. Before the hybrid tree is planted, powder insecticide can be mixed with the soil for prevention and control; after planting, if insect damage is found, emulsion insecticide can be applied with water for prevention and control.

The plastic pruning of the hybrid tree refers to the control of the tree type of the hybrid tree for greening purposes, so as to adapt to the actual needs and play the role of beautifying the environment and beautifying the landscape. The branches and leaves of the hybrid tree are luxuriant, and the side branches are well developed. Before the sapling grows to 80 cm, it is not suitable to operate to ensure the nutritional status of the tree. When the sapling grows to 80 cm, the excess branches of the sapling can be thinned out, and about 5 branches at the top can be kept. For the branches with better shape, similar pruning will be carried out on the sapling branches on a regular basis in the future, and the trunk height of the tree body will be gradually increased. Do not prematurely and excessively prune. Due to the strong germination ability and rapid growth of the side branches of the hybrid tree, the trunk is prone to bending or tilting, which affects the aesthetics of the tree. Generally, the branches are pruned every month. It is recommended to perform fixed-drying treatment in the nursery. The tree grows to 3m It can be fixed to dry when it is left or right, and then the 2-year-old seedlings after fixed drying are transplanted.

Hybrid mulberry can overwinter safely in most parts of the north where the lowest temperature is higher than -10°C. If the lowest temperature in the planting place is lower than -10°C or extreme weather below -10°C may occur, appropriate cold protection measures should be taken for the seedlings. (1) Moderate pruning of seedlings. (2) Remove weeds, turn over the land, cultivate soil at the base of the tree roots, and pour antifreeze water thoroughly. (3) Bind the trunk with rice straw, straw rope, etc. to keep warm and keep out the cold. In colder areas, a layer of plastic sheeting needs to be added outside. (4) Covering the ground with crop stalks or covering tree holes with mulch can increase the surface temperature (3-5 degrees) and maintain a certain humidity (above 80%) and prevent spring salt return. In addition, the method of straw mulching can also be used as fertilizer to supply saplings to grow after the straw rots. (5) When conditions permit in some places where the planting of seedlings is relatively concentrated, grass thatch can be used to build a windshield or a plastic sheet can be used to build a greenhouse without affecting the viewing effect.

Claims (10)

1. A method for ecological afforestation of coastal saline-alkali land, comprising the steps of: planting a hybrid tree on the coastal saline-alkali land with a salt content below 1%, so that the coastal saline-alkali land is afforested; When the salt content of the coastal saline-alkali land is 1%-1.5%, before the planting of hybrid trees, land consolidation is required so that the salt content of the coastal saline-alkali land after land consolidation is below 1%, and the The method for land consolidation comprises the following steps 1)-4): 1) A road with the same length as the rectangular land and a width of 3-5m is set in the center of the entire rectangular land, and the road divides the rectangular land after subtracting the area of the road into two small rectangular lands with equal areas ; On the two small rectangular lands, open a plurality of drainage ditches parallel to the broadside of the small rectangular lands respectively, the top width of the ditch is 3m, and the depth of the ditch is 1-2m, and the length of the ditch is the same as that of the small rectangular lands. The width of the ditch is the same, and the ditch wall should be inclined at an angle of 45 degrees to the outside of the ditch; the multiple ditches on each small rectangular land communicate with the outside of the entire rectangular land and communicate with each other; the multiple drainage ditch The small rectangular land is divided into several independent strips and terraces with equal areas respectively; the width of the strips and terraces is 8-12m, and the length is consistent with the length of the small rectangular land; 2) base fertilizer is applied, and the base fertilizer application includes excavating multiple ditches for applying base fertilizer parallel to the long sides of the bar and the terrace on each bar and terrace, with a width of 20 ± 3 centimeters and a depth of 30 ± 5 centimeters , the ditch distance is 1m, 3000 kg/mu of organic fertilizer is applied in the ditch, and 50 kg/mu of NPK compound fertilizer is added at the same time; the ditch is filled with soil and left for 15 days to let the organic fertilizer rot; 3) Build the irrigation system: combine the seedling belts to be planted, and set up and lay suitable drip irrigation belts; 4) Ridging: In each of the strips and terraces, along the direction parallel to the long sides of the strips and terraces, make multiple high ridges with a width of 50 centimeters and a height of 20 centimeters. The distance between them is 50 cm, and the distance is used as a walkway; a planting furrow of 20 cm × 20 cm is excavated in the center of the high ridge; In the field, design the drainage ditches parallel to the broadsides of the strips and terraces at intervals of 10m respectively. The top width of the drainage ditches is 50 centimeters, 20 centimeters deep, and the ditch length is the same as the width of the strips and terraces. Consistent, the ditch wall should be inclined at an angle of 45 degrees to the outside of the ditch, and slope protection should be done well; 5) Plant the hybrid mulberry tree in the planting ditch described in step 4). 2. The method according to claim 1, characterized in that: in the step 1), the width of the road is 4m; the depth of the ditch is 1.5m; the width of the strip and the terrace are 10m; In the step 2), the groove width is 20 cm, and the groove depth is 30 cm. 3. The method according to claim 1 or 2, characterized in that: before planting the hybrid tree, seedling hardening also needs to be done, and said hardening comprises: adopting a sunshade net to build a seedling hardening shed about two meters high, Place the seedlings in the shed at a distance of 0-5 cm, and ventilate in a timely manner in the morning and evening. When the light intensity is greater than 50,000 lux and the temperature is higher than 35 degrees on a sunny day, put down the shade net to cool down. Depending on the specific situation, combined with water and fertilizer management, gradually extend the ventilation time and Light time, after 10-15 days, strong seedlings can be cultivated. 4. method according to claim 3, is characterized in that: the condition of described planting hybrid tree comprises following 1)-5): 1) Planting in months when the minimum temperature is higher than 10°C; 2) The planting density is selected as 1m×1m; 3) Avoid planting at noon when the sun is strong; 4) The planting depth should not exceed 20 cm; 5) Fill the planting water in time after planting; Said planting hybrid tree is planting the strong seedlings cultivated in claim 3. 5. The method according to claim 4, characterized in that: the month when the minimum air temperature is higher than 10°C in the condition 1) is planted in the first half of the year in northern my country; The condition 3) avoiding planting at noon when the sun is strong is planting in the evening. 6. The method according to claim 3, characterized in that: after planting the hybrid mulberry tree, irrigation and/or fertilization are required; the planting hybrid mulberry tree is the strong seedling cultivated by planting claim 3; The irrigation includes: watering every other day in the first week after the strong seedlings are planted, watering at least twice in the second week; after the strong seedlings survive, watering once a week depending on the drought situation on the ground, and once in the rainy season , do not water; after the seedlings are quite long, before winter, water the frozen water in a timely manner; the main points of watering include: each watering should be watered enough, and do not water halfway; The fertilization includes: after the seedlings have survived for 2 months, topdressing the high-nitrogen compound fertilizer once at a rate of 0.2 kg/plant during the peak growth season, and applying rice and corn stalks to the whole ground to cover the ground after the leaves fall in autumn. 7. The method according to claim 1 or 2, characterized in that: after the hybrid tree is planted, pest control, pruning and/or overwintering management and protection are required; The control of diseases and insect pests includes: spraying 2000-3000 times liquid of 1.8% of the insecticide gram EC to prevent and control aphids and/or mites; before the hybrid tree is planted, mix the insecticide powder with the soil to prevent and control moths Pests; after planting, if moth pests are found, the emulsion insecticide is applied with water for control; the insecticide is a common insecticide for preventing and controlling soil-borne pests in the market; The plastic pruning includes: when the hybrid tree sapling grows to 80 cm, the excess branches of the sapling are thinned out, and the top 5 branches with better shape are retained, and the sapling branches are similarly pruned every month to gradually increase The trunk of the tree is high, so it must not be prematurely and excessively pruned. When the tree grows to 3m, it will be dry, and then the 2-year-old seedlings after the dryness will be transplanted; The overwintering management and protection include: if the lowest temperature in the planting place is lower than -10°C or extreme weather lower than -10°C may occur, appropriate cold protection measures must be taken for the seedlings, and the cold protection measures include any of the following 1)-5) One said: 1) Appropriate pruning is carried out to seedlings; 2) Remove weeds, plow the land, cultivate soil at the base of the tree roots, and pour antifreeze water; 3) Bind the trunk with rice straw and straw rope to keep warm and keep out the cold. In colder areas, a layer of plastic sheeting needs to be added outside; 4) Cover the ground with crop straw or cover the tree hole with plastic film; 5) When conditions permit in some places where the planting of seedlings is relatively concentrated, use grass thatch to build a windshield or plastic sheet to build a greenhouse without affecting the viewing effect. 8. The method according to claim 1 or 2, characterized in that: the coastal saline-alkali land is tidal flat saline-alkali land. 9. The application of the arbitrary described method of claim 1-7 in coastal saline-alkali land ecological afforestation. 10. The application according to claim 9, characterized in that: the coastal saline-alkali land is tidal flat saline-alkali land.