The latest course of Larix gmelinii planting techniques

Larix gmelinii is a kind of pine tree, it is a deciduous tree of Larix family, the main forest composition tree species in Northeast China and Inner Mongolia forest region, one of the three major coniferous timber forest species in Northeast China, which is widely distributed naturally. It is the most cold-tolerant among coniferous species, and its vertical distribution reaches the upper limit of forest distribution. Let's take a look at larch planting techniques.

Cultivation value of larch

Larch wood is heavy and solid, with high compressive and bending strength, decay resistance and high technological value. it is an excellent material for electric poles, sleepers, bridges, pillars, vehicles, construction and so on. The tree is tall and straight, the crown is beautiful, the root system is very developed, the anti-smoking ability is strong, is also an excellent landscaping tree species. Larch arabinogalactan is extracted from larch wood with water or dilute alkali. It is a kind of gum with low viscosity and high dispersion, which is mainly used in medicine, food and so on.

Growth habits of larch

Larix gmelinii is a light-loving strong positive tree species with strong adaptability and a wide range of adaptation to soil water conditions and soil nutrient conditions. it is most suitable to grow best in moist, well-drained, well-ventilated, deep and fertile soil. Larix gmelinii can also grow on dry and barren mountain slopes or in perennial water wetlands or lowlands, but it is poor in growth and resistant to low temperature and cold. Generally, it can grow normally even when the lowest temperature reaches-50 ℃. Distributed in Northeastern University, Xiaoxinganling, Laoyeling, Changbai Mountain, Northwest Liaoning, Northwestern Hebei, Shanxi, Qinling of Shaanxi, Southern Gansu, Northern, Western and Southwest Sichuan, Northwest Yunnan, Southern and Eastern Xizang, Altai Mountain and Eastern Tianshan Mountains, often forming a large area of simple forest, or mixed with other coniferous and broad-leaved tree species.

Larch seedling cultivation

1. Nursery site selection: choose convenient transportation, flat terrain, good drainage and irrigation, deep soil layer, loose soil, more fertile neutral or slightly acidic sandy soil or light loam to raise seedlings, winter soil preparation, applying organic fertilizer 750kg per mu, turning over 30cm deeply, spraying 1:10 times ferrous sulfate solution evenly before sowing, raking flat bed after drying, the bed is 15 cm high, 1 meter wide and 25 cm apart.

2. Seed treatment: before sowing, larch seeds were soaked in 0.5% potassium permanganate solution for 4 hours, washed with clean water and then soaked in 45 ℃ warm water for 24 hours, slightly dried and mixed with river sand three times the size of the seeds, and then placed in the germination pit to accelerate germination. The germination pit should be dug in the leeward direction, 50 cm deep and 50 cm wide, covered with plastic film, covered with grass curtain at night, the seeds should be turned evenly once a day, and the seeds can be sown after 30% of the seeds are cracked.

3. Sowing technology: it can be sowed when the surface temperature is above 10 ℃. The sowing rate is 4-4.5 kg / square meter, and the seedbed should be filled with enough bottom water before sowing. The use of strip sowing, ditch distance of 10 cm 15 cm, ditch depth 1 cm, cover 1 cm thick fine sand loam, and cover a layer of straw, it is appropriate to cover the grass, and immediately spray water, and then spray water a small number of times a day, often keep the bed moist. When 30% of the seedlings are unearthed, the grass will be unearthed. After the seedlings are all unearthed, the grass will be uncovered. The grass should be uncovered on a cloudy day or in the evening, and the grass should be watered in time after uncovering.

4. Seedling stage management: timely watering after seedling emergence, a few times, keeping the seedling bed moist, paying attention to loosening soil and weeding, weeding combined with loosening soil, building a front shed above the seedling bed, keeping the transmittance at 60-70%. The disease of larch seedling is mainly blight, and the insect pests are grub and mole cricket, so attention should be paid to the control in the process of seedling cultivation.

Larch planting technique

1. Land preparation: generally adopt burrowing, fish-scale pits and horizontal ditches for soil preparation. On the site conditions of new cutting sites, abandoned farmland with fewer weeds, and sparse shrubs, burrowing site preparation with a specification of 40 cm × 40 cm × 30 cm, barren hills, old cutting sites, shrubs and weeds should be carried out before site preparation. The fish scale pit site preparation specification is 50 cm × 50 cm × 40 cm, or horizontal ditch preparation with a ditch length of 70 cm × 100 cm and a width of 40 cm. It is 30cm to 40cm deep.

2. Planting density: afforestation with 2-year-old 1-2 qualified seedlings, afforestation in areas with better site conditions, planting density of 1600 to 1700 plants per hectare, row spacing of 2 × 3 meters, and planting density of 2500 plants per hectare in areas with relatively poor site conditions. the planting density should be 2 × 2 meters or 1.6 × 2.5 meters.

3. Fertilizer and water management: after larch is planted, water is applied twice in a week, then the soil can be loosened and the soil moisture can be preserved, and then it can be watered again in early May. After that, if the weather is not dry, fertilizer can be applied once in June and ferrous sulfate once in August. Dig a hole at the edge of the plant. In loosening soil and weeding, can be carried out once every 20 days, requiring serious and meticulous, generally up to 4 to 5 cm deep, requiring hoing evenly, loose soil without bumpy, grass hoe clean, pick clean.

4. Disease prevention and control: before the peak of sporangium emission in spring and summer, spray 1VRV 100 Bordeaux solution, 50% acetaminophen 500 × 800, 70% Dexong 500 × 800, 65% zinc 500 times, 45% Dysenamine 200 × 300, and apply 621 smoke agent, chlorothalonil smoke remover or sulfur smoke agent to the closed young forest or seriously ill adult forest.