(1) cold bed seedling raising.
It is also called yang bed seedling raising. In the south, cold beds are called "cold pits" or "seedling sheds". This is a way of raising seedlings by sunlight heating. Because of the poor temperature conditions, the ability to artificially control the temperature of the seedbed is small, so the seedling age is longer. According to the external form of cooling bed, it can be divided into single inclined plane cooling bed, double inclined plane cooling bed and arch cooling bed. The monoclinic cold bed seedbed faces south, and is long from east to west, with a wind wall on the north side. Seedbed covers are inclined from north to south, including glass, plastic film, pu mat, reed thatch, grass thatch and so on. The double-inclined cold bed seedling shed is roof-shaped and inclined to both sides, and the covering is mostly glass and grass. The arched cold bed is tied into a semi-arched circle on the ground with bamboo poles, and covered with plastic film and grass. In addition, there are ways to build a seedbed in a plastic shed and then build a small arch shed on the seedbed.
(2) Raising seedlings in hotbeds.
The south calls hotbeds "hot pits". Hotbed seedling raising is a seedling raising method developed on the basis of cold bed seedling raising with artificial heating equipment. At present, electrothermal hotbeds are commonly used to raise seedlings. Electric hotbed seedling raising is to create temperature conditions suitable for the growth and development of processed tomato seedlings by using special insulated resistance wires to generate heat and manual control. On the basis of the cooling bed structure, an electric heating wire and a controller are added. The bed temperature and soil temperature of electric hotbed seedling can be manually adjusted according to the needs of seedling growth, which can improve the speed of seed germination and seedling growth and save seeds and labor. It is an advanced seedling raising method vigorously promoted in China at present. To be an electric hotbed, you need to prepare items such as electric hotline and thermostat. The specific method is: first level the bottom of the seedbed, and then bury the electric hotline. When burying the thread, nail small stakes at both ends of the seedbed according to the row spacing of 8 ~ 12cm, then pull them back and forth, straighten and tighten them one by one. The middle of the frame can be thinner, and the frame can be denser, keeping the line spacing, not overlapping, not crossing and not knotting. Be sure to put the two ends of the heating wire at one end of the frame to facilitate temperature control. Turn on the power supply after the electric hot wire of the seedbed is covered, check whether the circuit is smooth, and turn off the power supply after there is no problem. Then cover the heating wire with 2 ~ 3 cm thick soil, press the heating wire, and then spread 8 ~ 10 cm thick nutrient soil on it for sowing. The following problems should be paid attention to when using electric hotline to raise seedlings: the electric hotline must be laid by regular electricians; Don't cross the live wire and the zero wire of the electric hotline to avoid fire; When pulling wires, loosen the soil first, don't cut off the electric hotline, then hang them out one by one, don't pull hard, and don't dig hard with a shovel; Electric hotlines must be laid for each crop, and electric hotlines for more than one crop shall not be laid.
(3) Raising seedlings in greenhouse.
Using solar greenhouse or heating greenhouse to raise seedlings, the cover is glass, plastic film and mat or quilt. Mostly used in northern areas with low temperature in spring. Because of the large space in the greenhouse, it can prevent the sudden drop of outside temperature from affecting the seedlings, and it is safer to raise seedlings. The temperature in the greenhouse is high, and the seedlings grow fast. Therefore, it is necessary to ventilate and adjust the temperature in time, otherwise it is easy to cause the seedlings to grow white.
(4) industrialized plug seedling raising.
It is a modern seedling raising method which uses plug, peat, vermiculite and other light materials as seedling raising matrix and adopts mechanical precision sowing to form seedlings once. It has the advantages of mechanized production, labor saving, high efficiency, shortened seedling age 10 ~ 20 days, light seedling pile, weight only110 of mound, energy and space saving, convenient standardized management and cultivation of qualified commercial seedlings. The seedlings are nodule-shaped, and there is no delay after planting, which is suitable for mechanized transplanting and long-distance transportation. Suitable for large-scale cultivation of commercial seedlings.
(5) Seedling tray: according to the purpose of seedlings, non-perforated seedling tray and perforated seedling tray can be selected. The seedling tray has 72 holes, 128 holes. Before sowing, put a proper amount of nutrient soil in the hole, put the seedling tray on the flat bed and sow according to the hole. The germination rate of seeds is above 90%, and each hole can be planted with 1 ~ 2 seeds (dry seeds) or 1 germinated seeds. The germination rate of seeds is below 80%. Sow 2 ~ 3 seeds (dry seeds) in each hole, and cover them with plastic film after covering with soil.