Key Technical Points for Raising Taxus Seedlings in Container Bags and Afforestation
Taxus (yew), a tree species under first-class national key protection, is an evergreen tree reaching 30 m in height, with bark grayish brown, reddish brown, or dark brown, splitting into strips; first-year branches green or pale yellow-green; leaves linear, slightly curved or straight, apex gradually and slightly acuminate, with dense, uniform, minute rounded horn-like papillary protuberances on the midrib beneath; seeds ovoid, with a protruding short blunt tip at the apex; heartwood orange-red, sapwood pale yellowish brown, grain straight, extremely hard and durable, used for high-grade furniture, piano casings, joinery, etc., and regarded by the public as a treasure. Taxus grows mostly wild. Because its root system is not well developed, the survival rate of bare-root seedlings planted on hillsides for afforestation is low and it is difficult to establish a forest, whereas container seedlings have a high survival rate when planted on hillsides for afforestation, readily establish a forest, and grow somewhat faster than bare-root seedlings.
I. Biological Characteristics
Produced south of the Qinling Mountains, distributed in Yunnan, Guizhou, and Sichuan, often growing on mountain land above 1000 m to 1200 m in elevation; shade-loving, fond of a warm and humid climate, and fond of slightly acidic or neutral soil.
II. Seed Collection and Storage
The seed collection time should be chosen in October, collecting seeds after Cold Dew. When collecting seeds, collect seeds from mother trees over 20 years old that are robust in growth and free of pests and diseases. After collection, store the seeds in sand with fine sand, and take care to keep the room well ventilated at all times, turning the sand and the seeds to avoid the seeds becoming moldy and rotten.
III. Preparation of Nutrient Soil and Sowing
1. Preparation of Nutrient Soil
Generally, take subsoil and crush it, then mix it thoroughly with humus from the forest at a ratio of 2:8, then apply a nitrogen-phosphorus-potassium ternary compound fertilizer; the compound fertilizer rate is generally 20 kg per cubic meter of soil. Mix the fertilizer and the soil thoroughly and prepare nutrient soil through fermentation. After the nutrient soil is prepared, disinfect it with dexon, then mix it thoroughly with the nutrient soil and it is ready.
2. Filling the Container Bags
Generally, cylindrical plastic container bags are used. Put the prepared nutrient soil into the container bags; the nutrient soil should fill and pack the container bags fully, then place the container bags one by one on a level seedling bed. The width of the seedling bed is generally 1.2 m.
3. Sowing
The sowing time is in late February. Before sowing, soak the seeds in warm water at 60°C for 2 hours, then carry out a 3-4 day pregermination treatment before sowing. When sowing, first poke a hole in the middle of the nutrient soil in the container bag with a thin wooden stick to a depth of about 3 cm, then put the seed into the hole and seal the hole with nutrient soil to cover the seed.
IV. Seedling Stage Management
About 50 days after sowing, the seedlings begin to emerge. The young seedling stage is generally in April-May. If continuous high-temperature weather occurs, shade and water, and weed in time. Container bags in which seedlings have not emerged should be reseeded or replanted with seedlings. The established seedling stage is generally in July-September, when fertilization should be carried out; the fertilizer is generally a nitrogen-phosphorus-potassium ternary compound fertilizer, and the number of fertilizer applications is generally 3: the first in late June at about 2 kg per mu, the second in late July at about 4 kg per mu, and the third in late August at about 8 kg. If high-temperature and drought weather occurs, water, generally once every 3-5 days.
V. Afforestation
1. Selection of Afforestation Site
The afforestation site is selected at 1000 m to 1200 m in elevation, on shady slopes or semi-shady slopes, on purple soil or yellow loam soil, with a soil layer more than 40 cm thick.
2. Afforestation Method and Afforestation Density
Taxus afforestation should adopt a mixed-forest method; Taxus should be mixed with evergreen broadleaf trees such as Castanopsis, with a mixing ratio of Taxus:broadleaf trees = 6:4. The mixed-forest method uses row-to-row mixing, with an afforestation density of 220 plants per mu and a spacing of 1.5 m x 2 m.
3. Afforestation Site Preparation and Planting
Clear the weeds on the afforestation site. The site preparation time is October-December. The site preparation dimensions are 30 cm x 30 cm x 20 cm for Taxus and 40 cm x 40 cm x 30 cm for broadleaf trees. The planting time is January. When lifting and transporting seedlings, use bamboo baskets to transport them to the afforestation site to avoid damaging the seedlings or the nutrient soil. When planting, place the nutrient-bag seedling into the planting hole, cut or tear open the nutrient bag with scissors, then cover with soil.
4. Tending of Young Plantations
(1) Weeding, loosening soil, and expanding planting holes
The tending period is 3 years, carried out in late May; completely remove weeds, and loosen the soil and expand the holes around the planting holes of the seedlings.
(2) Fertilization
The fertilization period is 3 years, with fertilization once each year. The fertilizer is generally a nitrogen-phosphorus-potassium ternary compound fertilizer: in the first year, apply 0.05 kg per plant; in the second year, apply 0.1 kg per plant; and in the third year, apply 0.15 kg per plant.