Cultivation techniques of pine trees





Planting and nursery selection

The nursery land should choose sandy loam with loose soil and deep soil layer, flat terrain, good drainage, and irrigation conditions. The root system of white bark pine has mycorrhizal fungus symbiosis, and mycorrhizal fungus has a good effect on promoting the growth of seedlings, that is, it can promote the roots of the seedlings to absorb water and nutrients in the soil, and improve the drought and disease resistance of the seedlings. Therefore, the breeding ground of white bark pine is suitable for continuous cropping.


Sand storage and germination of seeds

Adopt indoor layered sand storage and accelerating germination in winter. The sand accelerating germination should be carried out before the soil freezes. Choose clean houses with intact doors and windows for comprehensive disinfection. Pile the disinfected pure sand indoors with a humidity of about 60%. Use a pure cloth bag to pack the seeds and sand in a ratio of 1:3, so that the volume of sand and seeds account for the total cloth bag. 30% to 40% of the volume, then bury the cloth bag flat in the sand, and cover the sand pile with grass curtains, pay attention to ventilation, moisturizing and anti-freezing. The next year, when the seeds have 40% to 50% cracks, they can be sown.

The seedling raising method adopts container seedling raising or raising seedling on high and low bed. Seedbed nursery adopts drill seeding, with a sowing amount of 40-50 kg per mu. After sowing, it is covered with plastic film or straw, and the covered straw should be disinfected with 1% formalin or carbendazim solution.


Seedling management

25 to 30 days after sowing, the seedlings are unearthed with their shells, and the shells fall off on their own in about 15 days. During this period, prevent the destruction of birds and animals. After the seed husk falls off, the prevention of wilt should be strengthened, and the seedlings should be sprayed alternately with carbendazim and ferrous sulfate 2 to 3 times a week. Use an aqueous solution of ferrous sulfate with a concentration of 0.3% to 0.5%. One person in the front sprays the medicine, and one person in the back washes with water, otherwise it is prone to phytotoxicity. The seedlings should be watered at the right time and appropriate amount during the growth process, and pay attention to loosening the soil and weeding.

White pine seedlings grow slowly, the height of the first year is only 4 cm ~ 5 cm, the second year is about 10 cm, the height of 4 to 5 years old is 30 cm to 40 cm, and the height of 10 years old is about 1 meter. The seedlings need to be transplanted 2 to 3 times in the process of cultivating to grow into large seedlings. Usually 1 to 2 years old seedlings are transplanted for the first time, and then cultivated for 1 to 2 years to go uphill for afforestation. The 5-year-old seedlings are transplanted for the second time, and the 8-year-old seedlings are transplanted for the third time.


Forest variation

Pine trees are cross-pollinated plants, and there are wide variations among individuals, forest stands, and provenance (origin). The types of pine trees can be distinguished based on individual variation. For example, in Zunhua, Hebei, China, Chinese pine is traditionally divided into three types: red bark pine (Chinese pine), which has heavy material and color, and has more resin; yellow bark pine (bran pine), which has white material and less resin; Thousand bark pine (coarse bark pine), heavy in material, yellow. In the south, Masson pine is divided into copper pine (thin-skinned) and iron pine (thick-skin). Contemporary research on individual variation of pine trees still classifies pine tree types (Chinese pine, Masson pine, Pinus sylvestris, Korean pine, etc.) according to the thickness and color of the bark. In addition to the bark characteristics, the width and density of the canopy are often used as the basis for classification (masson pine, Chinese pine). Extensive provenance experiments have shown that pine trees generally have geographic variations, and therefore, different ecological types can be divided within the same species. The study of the geographic variation of pine trees is the basis for seed zoning and seed selection.


Planting afforestation

Planting and afforestation techniques vary with the types of seedlings. The container seedlings have soil lumps, and the root system is not easily damaged during the planting process, so the survival rate is higher. The afforestation technology is also relatively simple. Bare-rooted seedlings are mostly damaged in the process of seedling and planting. Their survival depends on the regeneration ability of the root system and environmental conditions, as well as the quality of seedlings, age, planting season and planting methods. Because of the developed root system and large rhizome ratio, the survival rate of transplanted seedlings is generally higher than that of original seedlings. The age of afforestation of seedlings mainly depends on the tree species. For Korean pine, 2-3 year-old seedlings are generally appropriate, but in areas where there are luxuriant weeds in logging areas, 3 to 4-year-old seedlings are appropriate. In North China, 1.5-year-old seedlings are mostly used for afforestation in the rainy season, and 2-year-old seedlings or transplanted seedlings are mostly used for spring afforestation. Masson pine is planted with 1-year-old seedlings or even with autumn sowing of the hundred-day seedlings unearthed in the following spring. Generally, early spring is the suitable afforestation season, while in North China and Northwest China where the spring drought is severe, you can choose rainy July and August for afforestation. There are two kinds of planting methods: hole planting and seam planting. It is necessary to keep the roots of the seedlings moist. When planting, pay attention to the extension of the root system and make sure that the roots are covered with soil. Prune the injured and long side roots appropriately before planting. Afforestation in arid areas can take various measures to reduce evaporation from the surface. The configuration of seedlings is generally 1 plant per planting point, but there are also cluster plants, that is, 2 to 4 plants per planting point. Cong planting is beneficial to increase the survival rate and promote the growth of young trees. The planting density of pine trees is suitable for 4444 plants per hectare (row spacing ⒈5×1.5 meters), or 3333 plants per hectare (row spacing 1.5×2.0 meters), or even 2500 plants (row spacing 2×2 meters).

Pure pine forests are prone to pests, diseases and fires, and their productivity is low. Therefore, regardless of whether planting or direct seeding afforestation is used, attention should be paid to the establishment of mixed forests. The type of mixing can only be determined after long-term trials. In Northeast China, common tree species that are naturally mixed with red pine include purple tilia, maple birch, fish scale spruce, red spruce, and stinky fir.