Seedling management techniques of spruce species

Spruce is an evergreen tree, which is widely distributed in China. There are 20 species and 5 varieties, and 2 species are introduced and cultivated. It is the main regeneration tree species in cold temperate alpine forest area of China. It is shade-tolerant. The tree is 50 meters high, DBH 1.5 meters, flowering in late May, and cones mature in September-October. It is produced in the south of Xiaoxing 'anling Mountain and Huma River Basin on the north slope of Daxing' anling Mountain in Heilongjiang Province. Adapt to the soil layer deep, wet and good drainage environment, cold strong, lateral roots flat, weak wind resistance, easy to wind down. For temperate mountain acid tree species, high silica content, life up to 300 years, good material, elastic, wood texture straight, soft material, fine structure, bending flexibility and good acoustics, smooth slightly shiny, easy to process. It is a good building, bridge, sleeper, aviation, shipbuilding, plywood and furniture material, or musical instrument manufacturing and high-grade paper raw materials.

Spruce pine needles can extract aromatic oil, bark contains tannin, can extract glue. Spruce tree posture beautiful, fast growth, strong anti-pollution ability, is now a good tree species to build timber forests and greening around.

1. Land selection, soil preparation, fertilization and bed making

1. Choose land. Soil is the basis of seedling production, seedling success or not, the key lies in the choice of land. It is best to choose neutral or slightly acidic soil, sandy soil or light clay soil, the thickness of the soil layer is generally more than 70 cm, the thickness of the black soil layer is more than 20 cm, and it is best to choose a flat, fertile soil, sunny, convenient water source and good drainage area. Do not cultivate spruce seedlings in saline-alkali land, waterlogging pond, loess hillock, peat land and gravel land.

2. Soil preparation and fertilization. Spruce seedling stage, the root is thin and weak, the ability of root extension is very poor, there is no fine grain, loose soil conditions, seedling root extension is difficult to tie down. Therefore, we must cultivate carefully and lay a good foundation for the next step of production. In the process of soil preparation, it is necessary to rake, level and clean up the residues. At the same time, it is necessary to apply fertilizer. The best fertilizer is farm manure. The decomposed peat soil and a small amount of sawdust are mixed with human manure, and then some livestock manure is used for composting.

3. Make beds. According to the site conditions to determine the height of the bed, low-lying bed to do higher, higher terrain to do lower, according to local conditions. The general bed surface is 1.1 m-1.2 m wide, 10 m-20 m long, 20 cm-30 cm wide, the bed surface is fine and flat, and 1% ferrous sulfate solution should be used for bed surface disinfection 7 days before sowing.

II. Seed germination treatment

The purpose of germination is to promote the transformation of seed contents, early germination, enhance germination potential, shorten emergence time, enhance cold resistance, prolong growth period, and achieve the goal of rapid, uniform and complete emergence. At present, there are four seed germination methods: 1, mixed sand germination. 2. Water immersion for germination. 3. Low temperature germination. 4. Snow storage for germination.

In order to adapt to the climatic conditions in Northeast China, snow storage can be used to germinate. The specific method is: before the soil freezes, choose a well drained, shady place to dig a pit; the depth and width of the pit are about 50 cm, and the length depends on the number of seeds. First spread grass curtain or mat on the bottom of the pit, spread a layer of crushed ice about 10 cm thick, then mix the seeds and snow evenly according to 1:3 (or mix seeds, sand and snow according to 1:2:3) and put them into the pit, cultivate snow mounds on them, and cover them with grass curtain or soil. The snow is gradually removed in spring, but the grass curtain is still covered. Remove the cover 1 week before sowing, turn it upside down 2 - 3 times at noon every day to melt the ice and snow, and check the seeds. If the germination is good, control the low temperature until the sowing time. If germination is uneven or not urged well, then sun or indoor heating 1-3 days can be. If the amount of seeds is small, iron bucket or other containers can also be used, but the container should be placed in a cold house to prevent sun exposure, and the snow mixing ratio is the same as above.

III. Sowing

1. Sowing first pay attention to whether the soil moisture is appropriate. If it is too dry, it should be irrigated before sowing to ensure sufficient soil moisture, timely early sowing, early sowing and early emergence, strong resistance to pests, long growth period and good lignification. In case of late frost during seedling emergence period, it is necessary to always grasp the weather changes and do a good job of freezing prevention. Available firewood mixed sawdust cigarette to prevent late frost.

2. Cover soil immediately after sowing to avoid drying of soil and seeds affecting germination. The thickness of soil cover is closely related to seed germination and seedling emergence. Generally, the thickness of soil cover is 2-3 times of seed diameter. The thickness of the soil should be uniform, otherwise it will make the seedlings uneven, directly affecting the yield and quality of seedlings. The covering materials are mixed with peat soil, decomposed dung and sawdust in a certain proportion. These materials not only absorb water well but also have certain fertility. After covering the soil, it should be suppressed in time.

3. timely coverage. The purpose of mulch is to keep the soil moist, regulate the surface temperature, prevent topsoil hardening and weed growth, and it is more important for small seed mulch. Pine needles are used as mulch, which can achieve the purpose of aseptic labor saving, time saving and greatly reducing the cost of seedlings, and the effect is very good.

IV. Nurturing Management

1. Emergence stage. Before the seedlings are unearthed to molt, to prevent bird damage, special personnel can be used to drive birds or tie some grass people to scare or set up some wind noise.

2。Growth stage (seedling stage). First of all, create good growth conditions for seedlings, promote seedling growth and strengthen resistance. The second is pharmaceutical prevention. This period is an important period for nursery stock tending, and it is necessary to do a good job of forcing fertilizer, spraying, weeding and thinning seedlings, and controlling pests in due time. Spruce seedlings grow slowly, 1-year seedlings are only 2 cm-4 cm high, watered 2 times-4 times a day, less is better, reduce watering or stop irrigation in rainy season. Herbicide chemicals can be referred to larch management, but the dosage must be lower than larch. Thinning seedlings generally average 600 - 800 seedlings per square meter for 2-year-old seedlings, and 400 - 600 seedlings for 3-year-old seedlings.

3. Cold weather. Cold-proof is the key measure to reduce the loss of seedlings during winter. Soil cultivation is used for cold-proof, and its thickness exceeds 4 cm-5 cm of seedling height. The time of soil removal is after the spring dry wind, and physiological drought occurs prematurely.

V. Do a good job in pest control

The occurrence and spread of diseases and insect pests are closely related to local climate, temperature, humidity and soil conditions. We must implement the principle of "prevention first and active elimination" to do a good job in prevention. This includes selecting nursery land, strengthening management, sowing early in time, doing a good job in soil preparation, sprinkler irrigation, weeding, environmental sanitation, etc., and timely chemical prevention.