CN104982300A - Arid desert region protection forest system construction method - Google Patents

Abstract

The invention relates to the technical field of farmland shelterbelt construction, and specifically relates to an arid desert region protection forest system construction method. The method comprises the following steps of: seedling cultivation, wherein the seedling cultivation comprises pinus sylvestris seedling cultivation and poplar seedling cultivation, and for poplar, Erbai poplar and Xinjiang poplar are preferentially selected; selecting of an afforestation land and determining of specifications of planting pits; selecting of a planting season; determining of afforestation methods; and tending and management. According to the method provided by the invention, research is performed on such farmland shelterbelt transformation and construction technology as "using pines to change poplars, combining pines with poplars, and combining pines with pines". The research results can effectively overcome the technological bottlenecks in the combination reconstruction and shelterbelt construction in arid desert region pinus sylvestris, pinus sylvestris and poplar, and pinus sylvestris and picea mongolica, thereby having strong practical value and profound practical significance in the arid desert region shelterbelt restruction and construction.

Description

A method for constructing shelterbelt system in arid desert area

technical field

The invention relates to the technical field of farmland shelterbelt construction, in particular to a method for building a shelterbelt system in an arid desert area.

Background technique

In arid desert areas, farmland shelterbelts can regulate temperature, increase air humidity, reduce wind speed, reduce evaporation, improve farmland microclimate, reduce the damage of dry and hot wind to crops, and play a positive role in increasing agricultural production and farmers' income. However, in recent years, various disadvantages have appeared in the shelterbelt with poplar as the main body. For example, the shelterbelt with poplar as the main tree has a single species and serious pest damage. Once the beetle pest occurs, it will give poplar a devastating blow; The effect of the tree side is significant, the transpiration consumes a lot of water, and the contradiction between agriculture and forestry is becoming more and more prominent; moreover, the life span of the poplar shelterbelt system is short, the leafless period is long, and the time to fully exert its protective effect is short. In areas with poor soil texture, improper management is prone to occur. "Little old man tree", the protection system is extremely degraded, and the protection effect is seriously lost. Therefore, it is of great significance to choose tree species with strong resistance to diseases and insect pests, less water consumption and strong adaptability as the substitute tree species of poplar shelterbelts in arid desert areas.

For a long time, in arid desert areas, people are keen to use poplar as a tree species for farmland shelterbelts. In the 1990s, there were 142,100 hm ² of poplar plantations in Gansu Province, while mixed shelterbelts and evergreen tree species shelterbelts developed slowly and the number was small. Once a poplar shelterbelt is established, it will reach a mature forest after 20 years. At this time, it will not only require a large investment in transformation, but also the age of the transformed shelterbelt is too young to play a protective role in the short term. Consider the measures of "replacing pine with poplar, combining pine and poplar, and combining pine and pine" for the transformation and construction of shelterbelts, so that the shelterbelts can continuously and stably perform their protective functions while minimizing the impact on crops.

Pine sylvestris (Pinus sylvestris var.mongolica Litv.) has many excellent characteristics suitable for growth in arid desert areas, such as light-loving, drought-resistant, barren-resistant, and fast growth. In recent years, it has been successfully introduced in sandy lands such as northern Shaanxi, Ningxia, Gansu, and Qinghai. Pinus sylvestris can grow normally with proper artificial irrigation in arid desert areas, and shows strong adaptability in arid desert areas. Therefore, sylvestris pine will become one of the first choice tree species for building farmland shelterbelts in arid desert areas. Sand spruce is an excellent shelterbelt tree species that has been introduced and promoted in recent years. Experiments and demonstrations of seedling cultivation and afforestation have been carried out in arid desert areas. The afforestation survival rate is high and the adaptability is strong. It can also be used as an alternative tree species for existing shelterbelt tree species in arid desert areas. In the arid desert area, through the transformation and construction of farmland shelterbelts "using pine to poplar, combining pine and poplar, and combining pine and pine", the negative effects of poplar-based shelterbelts can be reduced, the protection time can be prolonged, and the protection efficiency can be improved, bringing considerable benefits. Ecological, economical benefits. Therefore, in the arid desert area, the development of shelterbelts dominated by evergreen tree species such as sylvestris sylvestris has broad prospects and great potential.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for transforming poplar shelterbelts in arid desert areas and building shelterbelts with Pinus sylvestris as the main body. In particular, sylvestris sylvestris is used as a substitute tree species for poplar over-mature forest transformation to transform existing farmland shelterbelts, evergreen tree species represented by sylvestris sylvestris are combined with poplars to build a shelterbelt, and sylvestris sylvestris is paired with sandy spruce to establish a shelterbelt system Methods.

In order to solve the above-mentioned technical problems, the present invention provides the following technical solutions: a method for building a shelterbelt system in an arid desert area, comprising the following steps:

(1) described nursery stock cultivation comprises the seedling stock cultivation of sylvestris sylvestris and poplar seedling cultivation. The method for cultivating seedlings is as follows: sylvestris sylvestris is transferred from Liaoning, Inner Mongolia and other places to cultivate young sylvestris sylvestris sylvestris, or seeds are used to raise seedlings, and then transplanted and cultivated. When the height of sylvestris sylvestris reaches 1.2m to 1.5m You can plant forests. Seed raising method: choose sandy soil with good drainage, make a flat bed, and then spread a layer of aeolian sand on the bed surface, with a thickness of about 3cm. Disinfect the sown Pinus sylvestris sylvestris seeds with 0.5% potassium permanganate for 10 minutes, then wash the seeds with water, and finally put them in sacks and place them in a sunny place for germination, turn the seeds from time to time, and sprinkle water in time until more than 60% of the seeds After whitening, sow in time. Adopt the ditching drill method, the ditch distance is 20-25cm, the ditch width is 8-10cm, and the depth is about 2cm. The germinated seeds are sown, and then covered with sandy soil with a thickness of 1cm. The bed surface is moist, and after emergence, shading, ventilation, pest control, weeding, timely irrigation and fertilization are carried out according to the season after emergence, and winter water is poured before the land freezes, and the soil is buried for the winter. The seedlings raised by the seeds can be transplanted and cultivated after more than 3 years of growth. The row spacing of transplanted plants is 20×20 cm. The poplar trees for the construction of shelterbelts are mainly local tree species Populus ericus and imported tree species Xinjiang Poplar. Poplar trees are mainly propagated by cuttings, which can be used to grow seedlings by cutting on site or transfer seedlings from other places. The method of raising seedlings by cuttings is to pick the ears before the poplar sap flows in spring, the cuttings are 15 cm long, the upper incision is cut horizontally, and the lower incision is obliquely cut, in a horseshoe shape. After cutting, bundle the cuttings together, 100 per bundle, and then place the cuttings in water to stimulate the roots, changing the water 1-2 times a day. If the temperature is high, calluses can be produced at the base of the cuttings. Cuttings are carried out after the temperature rises. Before cuttings, spread black plastic film to increase the ground temperature and reduce the growth of weeds. ° Angle, the cuttings are inserted into the ground about 12cm, leaving 1 to 2 full buds on the top, the row spacing of the cuttings is 25×60cm, watering in time after cuttings, and then watering once every 10 days, continuous watering 3 to 4 times, in the future according to the weather Irrigate in good time. During the rooting period of seedlings, weeds should be removed in time and buds should be wiped in time. Cutting seedlings can be used for shelterbelt construction after careful cultivation for 3 to 4 years. (2) The method for selecting the afforestation site and determining the specification of the planting pit on the afforestation site is that the afforestation site is preferably sandy soil with good irrigation and drainage, gentle terrain, light salinization, and no water accumulation. If a pure sylvestris sylvestris forest and inter-plant mixed forest are to be built, the width of the ditch in the plantation land is 1.5m, and the ditch depth is 30cm; if it is a ditch for farmland irrigation, the ditch depth is 40cm. Before planting Pinus sylvestris sylvestris, remove different trees and weeds in the ditch, and then dig pits. The distance between pits should be determined according to the type of shelterbelt to be built and the selected tree species. The size of the sylvestris pine planting pit is generally 1.5 times the size of the sylvestris pine soil ball; the size of the poplar bare root transplanting pit is excavated according to the size of the poplar root system, and the depth of the pit for 3-5 year old poplars is generally 40-50cm The diameter is between 25 and 30 cm. After planting, the root system can be stretched, and the pit is opened for use.

(3) the method that described afforestation season is selected is, the poplar afforestation season is carried out before the sap flows after soil thawing in spring, and my country's arid desert area is generally carried out in late April, if local seedlings can follow the afforestation with the seedlings, The seedlings from other places can be afforested after they are raised and transported back. If the time is too early, they can be planted in moist soil, and afforestation can be carried out in the afforestation season. Pinus sylvestris is transplanted with soil balls for afforestation using the soil ball binding method. The afforestation time can be spring and autumn, but spring afforestation is appropriate.

(4) The method for determining the described afforestation method is that Pinus sylvestris and sandy spruce will be transplanted with soil balls. % to 80%; poplars can be transplanted and planted with bare roots, and the depth of excavation depends on the size of poplar seedlings. In "replacing pine with poplar", it can be renewed at intervals, or a sylvestris pine shelterbelt can be built to replace the poplar in the sunny place. After the sylvestris sylvestris reaches a certain height, the poplar shelterbelt can be cut down. In the "combination of pine and pine", sylvestris pine and sand spruce can be mixed between rows. In the "combination of pine and poplar", sylvestris sylvestris can be mixed with Xinjiang poplar or Erbai poplar.

(5) The method of tending management is as follows: irrigate 7 to 9 times in the year of Pinus sylvestris sylvestris, and then irrigate 5 to 6 times a year, and start to end the slow seedling stage in the 4th year, and enter the fast-growing stage, and the annual growth can reach 50cm. Generally, there is no need for weeding after planting Pinus sylvestris. If there are shrubs, they can be removed in time, and weeds in the field do not need to be removed. It can improve the soil, increase soil nutrients, and provide certain nutrients for the growth of Pinus sylvestris. The crown of Pinus sylvestris is conical, with obvious dominance at the top, weak sprouting ability and small growth of side branches, and no pruning is required during the whole growth process. Pinus sylvestris has few pests and diseases, and generally no special control measures are needed, mainly quarantine and prevention, with simple operation and less workload.

Compared with the prior art, the present invention has the remarkable effects that: the present invention has the advantages of cultivating seedlings, selecting afforestation sites, determining afforestation seasons, excavating and planting soil balls of Pinus sylvestris and spruce, tending management, etc. Pine to Poplar, Pine and Poplar Combination, Pine and Pine Combination" farmland shelterbelt transformation and construction technology were studied, and the combination of sylvestris sylvestris, sylvestris sylvestris and poplar, and sylvestris sylvestris and sandy spruce in the arid desert area was solved. The technical bottleneck of shelterbelts has strong practical value.

Detailed ways

In order to make the object, technical solution and advantages of the present invention more clear, the present invention will be further described in detail below in conjunction with specific examples. It should be understood that the specific examples described here are only used to explain the present invention, not to limit the present invention.

A method for constructing a protection forest system in an arid desert area, comprising the following steps: cultivating seedlings. The seedling cultivation includes sylvestris sylvestris sylvestris seedlings and poplar saplings. The poplars are preferably Erbai poplar and Xinjiang poplar. When raising seedlings, when the height of sylvestris sylvestris reaches 1.2m-1.5m, transplant afforestation. When the seedlings are transported from the provenance for cultivation, when the height of the seedlings reaches 1.2m-1.5m, they can be used for shelterbelt construction; construct shelterbelt poplar Mainly the native tree species Erbai poplar and the imported tree species Xinjiang poplar. Poplar is mainly propagated by cuttings, and seedlings can be raised by cuttings on the spot, or transferred from other places. When poplar seedlings are raised, ear picking is carried out before the poplar sap flows in spring. The cuttings are 15 cm long. After cutting, bundle the cuttings together, 100 per bundle, and then place the cuttings in water to stimulate the roots, changing the water 1-2 times a day. If the temperature is high, calluses can be produced at the base of the cuttings. After the temperature rises, the cuttings are carried out, and black plastic film is spread before the cuttings to increase the ground temperature and reduce the growth of weeds. When cutting, use a cutting cone to open holes first. The cuttings and the ground are at an angle of 45°. The cuttings are inserted into the ground about 12cm, leaving 1-2 full buds on the top. Irrigate once a day, continuously irrigate 3 to 4 times, and then irrigate in due time according to the weather conditions. During the rooting period of seedlings, weeds should be removed in time and buds should be wiped in time. Cutting seedlings can be used for shelterbelt construction after careful cultivation for 3 to 4 years.

Selection of afforestation sites and determination of planting pit specifications on afforestation sites. Sandy loam land with good drainage and irrigation, gentle terrain, light salinization and no water accumulation is preferred for afforestation. If it is to build a pure pine forest and a mixed forest between trees, the width of the ditch in the forestation land is 1.5m, and the ditch depth is 30cm; if it is a ditch for farmland irrigation, the ditch depth is 40cm. Before planting Pinus sylvestris sylvestris, remove different trees and weeds in the ditch, and then dig pits. The distance between pits should be determined according to the type of shelterbelt to be built and the selected tree species. The size of the pit for planting sylvestris pine is generally 1.5 times the size of the soil ball of sylvestris pine. The size of the poplar bare root transplanting pit is excavated according to the size of the poplar root system. Generally, the depth of the pit for 3-5 year old poplars is 40-50cm The diameter is between 25 and 30 cm. After planting, the root system can be stretched, and the pit is opened for use.

Afforestation season selection. The poplar afforestation season is carried out after the soil is thawed in spring and before the sap flows. Generally, it is carried out in late April in the arid desert areas of our country. If it is the local seedlings, it can be afforested with the seedlings. The seedlings from other places can be planted after they are raised and transported back. Pinus sylvestris is transplanted with soil balls for afforestation using the soil ball binding method. The afforestation time can be spring and autumn, but spring afforestation is appropriate.

Afforestation methods. Pinus sylvestris and sandy spruce should be transplanted with soil balls. The size of the soil balls is 5 to 6 times the diameter of the seedlings, and the height of the soil balls is 70% to 80% of the diameter of the soil balls; poplars can be transplanted with bare roots. For planting, the depth of excavation depends on the size of poplar seedlings. In "replacing pine with poplar", it can be regenerated at intervals, or a sylvestris pine shelterbelt can be built to replace the poplar in the sunny place. After the sylvestris sylvestris reaches a certain height, the poplar shelterbelt can be cut down. In the "combination of pine and pine", sylvestris pine and sand spruce can be mixed between rows. In the "combination of pine and poplar", sylvestris sylvestris can be mixed with Xinjiang poplar or Erbai poplar.

Parenting management. Pinus sylvestris is irrigated 7-9 times in the first year of planting, and 5-6 times a year thereafter. The slow seedling stage ends in the fourth year and enters the fast-growing stage. The annual growth can reach more than 50cm. There is generally no need for weeding after planting Pinus sylvestris. If there are shrubs, they can be removed in time, and weeds in the field do not need to be removed, which can improve the soil, increase soil nutrients, and provide certain nutrients for the growth of Pinus sylvestris; the crown of Pinus sylvestris is conical, The top advantage is obvious, the side branches have weak tillering ability and small growth, and do not need to be pruned during the whole growth process; Pinus sylvestris has few diseases and insect pests, and generally does not need to take special control measures, mainly for quarantine and prevention. The operation is simple and the work Small quantity.

Below in conjunction with several examples concrete method of the present invention is carried out all-round elaboration:

Example 1

Construction of pure sylvestris sylvestris pine shelterbelts: After the soil thawed in early April 2001, single-row sylvestris sylvestris sylvestris pine shelterbelts were directly planted on the farmland without shelterbelts. The construction site of Pinus sylvestris forest belt is also an irrigation channel. Therefore, the planting of Pinus sylvestris is generally combined with the canal. The sylvestris sylvestris is planted on the side of the canal. The size of the loose soil ball is determined, generally 1.5 times the size of the soil ball, so as to facilitate the planting of seedlings. Choose sylvestris pine with vigorous growth, beautiful tree shape, and no pests and diseases as seedlings for building shelterbelts. Pinus sylvestris must be transplanted with a soil ball. The size of the soil ball is 5 to 6 times the diameter of the seedling, and the height of the soil ball is 70% to 80% of the diameter of the soil ball. The height of the transplanted Pinus sylvestris is 1.2 to 1.5m. The crown width is 0.8×0.8m～1.0×1.0m. When raising seedlings, dig 20cm straight down on the periphery of the diameter of the soil ball to remove the empty soil, and then dig in obliquely. Cut with scissors, do not forcibly use a shovel to shovel, and do not use a shovel to pry the soil ball to prevent the soil ball from breaking. After digging all around and leaving the bottom connected to the ground, you can use a sharp shovel to shovel off the hair root and tap root from the bottom. The soil ball After being completely separated from the ground, it is tied up with a wet straw rope, and then afforestation is carried out. During the transportation process, it must be slow, do not bump, and keep the soil ball intact, otherwise the survival rate of afforestation will be significantly reduced. The wind speed of afforestation in spring is relatively high, and it can be fixed with a rope on the side of the main wind direction to prevent the strong wind from blowing down or skewing the seedlings. After the seedlings are planted, they are irrigated in time, and then watered once every 10 days. After one month, the normal irrigation is resumed. The next year, the seedlings can be irrigated 5 to 6 times a year to grow normally. After the Pinus sylvestris is planted and survived, it is irrigated according to the time, and there is basically no need for daily management such as weed removal, pruning and spraying. In order to promote the rapid growth of Pinus sylvestris, fertilization can be carried out in spring. Fertilization and watering can be carried out at the same time. Urea can be applied, 15-20g per plant. The specific method is to dig a pit 15cm deep at a distance of 20-30cm from the main pole of Pinus sylvestris. , put chemical fertilizers into the pit and bury it with soil, and then irrigate. After 4 years of planting, the slow seedling stage of Pinus sylvestris ends and enters the fast-growing stage. The annual growth can reach more than 50cm. The growth of seedlings was investigated in 2015. The height of Pinus sylvestris is 8m, the crown width is 3.2-3.5m, the diameter at breast height is 8.5cm, and the canopy density is 75%, which can already play a protective role. The pure forest of Pinus sylvestris basically has no shade, which is conducive to the growth of Pinus sylvestris. It can enter the rapid growth period in 3 years, and the annual growth can reach more than 50cm. Pine is greatly affected by poplar in the early stage of poplar harvesting, and its growth is relatively slow. The side effects of Pinus sylvestris are small, and a "narrow forest belt, small grid" forest belt can be built, with a belt length of 100-150m.

Example 2

"Replacing pine with poplar" shelterbelt forest transformation: starting from the whole shelterbelt system, shelterbelts should be renewed at intervals, that is, shelterbelts in the same direction should be renewed at intervals, so as to reduce the disadvantage of the decline in protective function due to one-time renewal . One to two rows of Pinus sylvestris can be planted at a time. Pinus sylvestris is a light-loving plant. If two rows are planted, each plant in the second row should be planted in the middle of the first row to avoid shading. Increase light time. Pinus sylvestris belongs to the positive tree species. If it is multi-row poplar shelterbelts to be regenerated, the regeneration should start from the sunny side, and the shelterbelts on the sunny side should be thinned or planted on the original site after a certain distance. On the basis of the forest belt, a successor forest belt is planted on the sunny side of the forest belt. After the newly planted forest belt is closed and can fully exert its protective effect, the old forest belt can be gradually cut down.

"Converting pine to poplar" over-mature forest transformation was carried out in late April 2007. A 2m wide ditch with a depth of 30cm was opened on one side of the original poplar shelterbelt, and pits were dug at a distance of 1.3m from the poplar shelterbelt, with a row spacing of 3m. Carry out field planting of sylvestris sylvestris sylvestris, planting sylvestris sylvestris with soil balls, and the soil ball excavation method is the same as example 1. The initial height of Pinus sylvestris planting is 1.3m, and the crown width is 1.0×1.0m. After planting, watering is carried out in time. In the early stage of planting, watering is carried out every 10 days. Normal irrigation can be resumed after 4 consecutive irrigations. Just 6 times, other management such as pruning and weeding are basically unnecessary, and quarantine and prevention of diseases and insect pests are mainly used. Fertilization can be carried out according to the actual situation. The method of fertilization is the same as in Example 1. At present, the height of Pinus sylvestris shelterbelts reaches 4.5-5m, and the diameter at breast height is 8-10cm. After the poplar is excavated, Pinus sylvestris can play a protective role.

Example 3

"Combination of pine and poplar" to create a shelterbelt: The combined pine and poplar shelterbelt camp was built in mid-April 2003. A row of mixed shelterbelts were constructed by mixing Pinus sylvestris sylvestris and Populus sylvestris , and the distance between pine and Populus sylvestris was 2.5m. The afforestation method is basically the same as example 1. Dig a ditch next to the ditch on the side of the farmland. The ditch is 90 cm wide and 40 cm deep. Weeds and trees in the ditch are removed, and then afforestation is carried out. For afforestation, the height of Pinus sylvestris is 1.2-1.5m, the crown width is 0.8×1.0cm, and it is transplanted with soil balls. Irrigate in time after planting, and the rest of the management methods are the same as in Example 1. At the end of the survey, the survival rate of Pinus sylvestris reached over 98%. The poplar is selected from Xinjiang poplar, which comes from the 4-year-old seedlings cultivated by the Minqin Sand Control Station in Gansu Province, with a height of 3.0m and a DBH of 3-4cm. On the same horizontal line, then fill with soil, and after filling half of the pit, pull up the poplar by about 5-10cm by hand to stretch the root system of the poplar, and step on it firmly with your feet, and finally fill the pit with soil, and then carry out For irrigation, the first water should be fully irrigated, and the follow-up irrigation should be carried out simultaneously with Pinus sylvestris. The survival rate at the end of the survey reached 98%. At present, the height of Pinus sylvestris has reached 7.5m, the crown width is 2.8×3.0cm, and the diameter at breast height has reached 8-10cm; the height of Poplar Xinjiang has reached 13m, the crown width is 2.5×3.0m, and the average diameter at breast height is about 13cm. .

Example 4

"Combination of pine and pine" to build a protection forest system: firstly, sort out the planting ditch, remove the previously planted ash, black locust, white elm and other miscellaneous trees, and then open a 2.5m wide and 30cm deep ditch. The length of the ditch depends on the length of the farmland. . On April 28, 2014, a shelter forest with pine and sandy spruce mixed between rows was built, with a row spacing of 1.8m, a sandy spruce height of 1.5-1.8m, a crown width of 1.5-1.8m, a DBH of 1.5cm, and sandy spruce. The planting distance of fir is 3m; the height of Pinus sylvestris is 2.8-3m, the crown width is 1.6×1.8m, the diameter at breast height is 4.5-5cm, and the planting distance of Pinus sylvestris is also 3m. Pinus sylvestris came from seedlings raised in Minqin Sand Control Station, and spruce in sandy land came from Heshiketeng Banner. Both spruce in sandy land and Pinus sylvestris were transplanted with soil balls, and the excavation of soil balls was the same as in Example 1. After transplanting Pinus sylvestris and sandy spruce, irrigate in time. The head water should be irrigated thoroughly. After that, irrigate once every 10 days. After 4 times, the frequency of irrigation can be reduced. Irrigate once every 20 days. Irrigate 5-6 times. After planting Pine Pinus sylvestris and Sandy Spruce, there is basically no need for management such as weeding except for watering. Pests and diseases and fertilization can be determined according to the situation. In June, the survival rates of Pinus sylvestris and Sandy Spruce were investigated, and the survival rates were above 98%. This type of shelterbelt system has no obvious protection benefits in the short term, and after 4 to 5 years of stable growth, it can play a protective role when the height reaches more than 5m.

The above description is only a preferred example of the present invention, and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention within.

Claims (6)

1. A method for shelterbelt system construction in arid desert area, is characterized in that, comprises the following steps: (1) nursery stock cultivation, described nursery stock cultivation comprises sylvestris sylvestris sylvestris seedling cultivation and poplar seedling cultivation, and described poplar is preferably Erbai poplar and Xinjiang poplar; (2) Selection of afforestation land and determination of planting pit specifications on the afforestation land; (3) Selection of afforestation season; (4) Determination of afforestation methods; (5) Nursing management. 2. the method for a kind of shelterbelt system construction in arid desert area according to claim 1, is characterized in that: the method for nursery stock cultivation described in the step (1) is that Pinus sylvestris is transferred into seedlings from Liaoning, Inner Mongolia and other places to carry out Cultivate or use seeds for seedling cultivation. When using seeds for seedling cultivation, it will go through two stages of seed cultivation and seedling transplanting. After transplanting, transplant and afforestation will be carried out when the height of Pinus sylvestris reaches 1.2-1.5m. Seedling cultivation method As follows, select a well-drained sandy soil, disinfect and neutralize the soil with ferrous sulfate powder, make a flat bed after deep plowing, and then spread a layer of wind-sand soil on the bed surface with a thickness of about 3cm. Disinfect with 0.5% potassium permanganate for 10 minutes, then wash the seeds with water, and finally put them in a sack and place them in a sunny place for germination. During the germination period, turn the seeds from time to time and sprinkle water in time. After more than 60% of the seeds are white, they can be sown , using ditch drill method, the ditch distance is 20-25cm, the ditch width is 8-10cm, and the depth is about 2cm. Sow the germinated seeds, the seeding rate per mu is 5kg, cover the wind-sand soil with a thickness of 1cm after sowing, and then water in time, and the seedlings will emerge Spray water at the right time during the period to keep the bed surface moist. Shade, ventilate, prevent and control pests and diseases, weeding, timely irrigation and fertilization according to the season after emergence, and fill winter water before the land freezes and bury the soil for the winter. After the growth period of more than 3 years, transplanting and cultivation can be carried out. The row spacing of transplanted plants is 20×20cm. When planting and cultivating seedlings or transporting seedlings from other places to cultivate seedlings, the height of the seedlings reaches 1.2-1.5m and can be used to build shelterbelts. The poplars for building shelterbelts are mainly native species of poplar and imported species of Xinjiang poplar. Propagation is the main method. Seedlings can be grown locally or transferred from other places. The method of cutting seedlings is as follows. Before the poplar sap flows in spring, choose healthy and full branches of 1 to 2 years old for ear picking. The cutting length is 15cm, and the upper incision is cut flat. , cut obliquely at the lower incision, in the shape of a horseshoe. After cutting, bundle the cuttings together, 100 per bundle, then place the cuttings in water to accelerate the roots, and change the water 1 or 2 times a day. If the temperature is high, the cuttings will last for two weeks Callus can be produced at the rear base. Cuttings can be carried out after the temperature rises. Choose a well-drained sandy soil as a place for cutting seedlings, rake the land deeply, remove weeds, and spread black plastic film before cuttings to increase ground temperature and reduce weeds. The grass grows. When cutting, use the cutting cone to make holes first. The cuttings are at a 45° angle to the ground. The cuttings are inserted into the ground about 12cm, leaving 1-2 full buds on the top. Irrigate once every 10 days, and after 3-4 consecutive irrigations, perform irrigation according to the weather conditions. During the rooting period of seedlings, weeds should be removed in time, and buds should be wiped in time. The survival rate of poplar cuttings is very high, above 95%. Slightly lower, cutting seedlings can be used for shelterbelt construction after 3 to 4 years of careful cultivation. 3. the method for the construction of a kind of arid desert area protection forest system according to claim 1, is characterized in that: the selection of afforestation ground described in the step (2) and the method for determining the specification of planting pits on the afforestation ground are, the preferred drainage and irrigation of the afforestation ground For the sandy soil land with good, gentle terrain, light salinization and no water accumulation, if the pure forest and inter-plant mixed forest of Pinus sylvestris are to be built, the width of the ditch in the forestation land shall be 1.5m and the depth of the ditch shall be 30cm; Build a shelterbelt in the irrigated ditch with a depth of 40cm. Before planting seedlings, clear the different trees and weeds in the ditch, and then dig a hole. The distance between the pits is determined according to the type of shelterbelt to be built and the tree species selected. Pinus sylvestris and sandy spruce The size of the planting pit is generally 1.5 times the size of the sylvestris pine soil ball; the size of the poplar bare root transplanting pit is excavated according to the size of the poplar root system. Generally, the depth of the pit for 3 to 5-year-old poplars is between 40 and 50 cm. The diameter is between 25 and 30 cm. After planting, the root system can be stretched out, and the pit is opened for use. 4. the method for the construction of a kind of arid desert area shelterbelt system according to claim 1, is characterized in that: the method for afforestation season selection described in the step (3) is, poplar afforestation season after soil thawing in spring, sap It is carried out before the flow. Generally, it is carried out in mid-April in the arid desert areas of our country. If it is the local seedlings, it can be afforested with the seedlings. The seedlings from other places can be planted after they are raised and brought back. If the time is too early, they can be planted in moist soil. , Afforestation is carried out in the afforestation season. Pinus sylvestris and sandy spruce are transplanted with soil balls for afforestation by using the soil ball binding method. The afforestation time can be spring and autumn, but spring afforestation is appropriate. 5. the method for the construction of a kind of arid desert shelterbelt system according to claim 1, is characterized in that: the method for determining the afforestation mode described in the step (4) is that sylvestris sylvestris and sandy spruce all want to bring soil Ball transplanting, the size of the soil ball is 5 to 6 times the diameter of the seedlings, and the height of the soil ball is 70 to 80% of the diameter of the soil ball; poplars can be transplanted and planted with bare roots, and the excavation depth depends on the size of the poplar seedlings. In the reconstruction of the "pine to poplar" shelterbelt, it can be renewed at intervals, or a sylvestris sylvestris pine shelterbelt can be built to replace the poplar in the sunny place. After the sylvestris sylvestris reaches a certain height, the poplar shelterbelt can be cut down; In "Pinus sylvestris sylvestris and Populus sylvestris or poplar sylvestris are inter-crossed; in "combination of pine and pine", sylvestris sylvestris and spruce are inter-row mixed. 6. The method for the construction of a shelterbelt system in arid desert area according to claim 1, characterized in that: the method of tending management described in step (5) is to irrigate 7 to 9 times in the year when Pinus sylvestris is planted, and then every year thereafter Irrigate 5 to 6 times. In the fourth year, Pinus sylvestris begins to end the slow seedling stage and enters the fast-growing stage. The annual growth of Pinus sylvestris can reach 50cm. Generally, weeding is not required after planting. If there are shrubs, they can be removed in time, and weeds in the field are not needed. Clearing can improve the soil, increase soil nutrients, and provide certain nutrients for the growth of Pinus sylvestris. The crown of Pinus sylvestris is conical, with obvious dominance at the top, weak sprouting ability of side branches, and small growth. , Pine sylvestris has few diseases and insect pests, and generally does not need to take special control measures. It mainly focuses on quarantine and prevention, and the operation is simple and the workload is small.