Planting methods and technical requirements of licorice

1. The yield and quality of licorice were different under different climate and soil conditions. Liquoric root has strong adaptability to temperature condition, and moisture condition plays a decisive role in yield. According to the author's research, in the temperate precipitation 300~500mm area of China, the precipitation in general years can basically meet the growth of licorice, can be cultivated on the land without irrigation conditions, in order to obtain high quality seedlings transplanting, seedling should have irrigation conditions. In order to obtain high quality and high yield in the area with annual precipitation less than 200mm, irrigation conditions should be provided for both seedling and transplanting fields under the condition that there is no sufficient groundwater for licorice to be used directly (groundwater level 2~3m). In areas where precipitation is small (below 200mm) and irrigation conditions are not available, planting sites should be selected on both sides of rivers with groundwater levels above 2~3m or low-lying areas with good water accumulation conditions. In addition, in areas with heavy rainfall, it is necessary to avoid areas with ponding in rainy season. Licorrhiza uralensis L. has a wide adaptability to soil, with PH of about 8.0, salt content of 0.3% or less, deep loose gravel free sand soil to light soil quality of the land is good. Special attention should be paid to the introduction and cultivation outside the natural distribution area. On the basis of completing a cultivation experiment cycle, comprehensive evaluation should be carried out according to the yield, quality and economic benefit of medicinal materials, and then whether to carry out base scale cultivation should be decided.

2, seedling technology licorice seed hard rate is high, the general untreated seed natural germination rate is less than 20%. Water impermeability of seed coat is the main reason for seed germination and seedling emergence difficulties. Seed dormancy can be broken by concentrated sulfuric acid soaking, re-soaking at elevated temperature and grinding with rice mill. Now in the production and cultivation of more than the use of rice milling machine grinding seed treatment, both with rice milling machine grinding 1 to 2 times, in order not to see the seed broken for the degree. This method is inexpensive, convenient and reliable, and suitable for large-scale planting.

The suitable temperature for germination of licorice seeds was 15~30℃, below 5℃, it could not germinate, and above 40℃, it was easy to cause mildew. The suitable soil moisture content for seed germination was above 7.5%. Seedling sowing time should be timely early sowing, in order to extend the growth period, spring sowing in April to May, the specific time varies according to different regions, generally should be stable in the ground temperature above 10℃ is appropriate. Sowing seedling in large area, sowing rate is generally 90~120Kg/hm2, direct seeding cultivation is 45~60Kg/hm2, row spacing is 10~15cm, covering soil thickness is 2~ 3 cm, and covering soil thickness in sandy land should be increased appropriately compared with loam land.

Licorices like light, especially seedlings grow slowly, not tolerant of cane shade easily covered by grass, such as not weeding in time, will lead to a large number of dead seedlings. Therefore, it is very important to strengthen the cultivation and weeding. Weeding commission early, small, except. Because licorice seedlings are not drought-tolerant, irrigation conditions should be timely irrigated, depending on moisture content should be irrigated 2~3 times a year. The soil is sticky or saline-alkali heavy, irrigation can be used before sowing, and no irrigation can be used after sowing to prevent soil surface hardening and alkali return. In order to ensure high yield and high quality, scientific fertilization should be paid attention to. Compound fertilizer and micro-fertilizer should be applied together with organic fertilizer. Formula fertilization should be carried out according to soil conditions, and special fertilizer experiments should be carried out to better promote seedling growth.

3. Transplanting technique: seedlings can be transplanted before the soil freezes in autumn of the first year or after the soil thaws in spring of the second year. The diameter of root head of high quality seedlings should be more than 0.8 cm and the root length should be 30 ~40cm. During the process from seedling emergence to transplanting, water loss of seedlings should be strictly controlled. Two transplanting methods can be adopted: sub-burying transplanting (referred to as flat planting) or oblique transplanting (referred to as oblique planting). Flat planting means that the head and tail of the seedlings are placed horizontally in the seedling planting ditch, while oblique planting means that the roots of the seedlings are placed obliquely in the seedling planting ditch at a certain angle (10~20 degrees) from the top to the bottom, and then covered with soil to suppress them. The suitable depth of seedling planting is 5~10cm in soil layer, the thickness of soil cover for transplanting in autumn should be increased appropriately, and the thickness of soil cover in loamy soil should be slightly shallower than that in sandy soil. Transplanting density should depend on soil fertility and other conditions. Under the condition of abundant sunshine and fertile soil, the planting density is generally 25~30cm in row spacing and 10~13cm in plant spacing (up to 300 ~ 320 thousand plants/hm2). Transplanting density can be decreased in dry and barren soil. Under the condition of soil drought, it is necessary to irrigate enough water in time after transplanting, especially in autumn, to ensure the water balance in the seedlings before transplanting. To the east of Chifeng, there are pathogenic bacteria in the soil that cause root rot of licorice. Before transplanting, it is necessary to dip roots with fungicides that do not cause residual poison of medicinal materials.

4. The key to the success or failure of licorice cultivation is deep ploughing before seeding. The best ploughing depth is 40cm, which is conducive to the growth of licorice roots and the formation of high-quality transplanted seedlings. If the tillage layer is shallow, the root growth of licorice will be blocked, and the main root will easily diverge, affecting the quality and yield of the product. Before sowing, we should irrigate sole water, and sow when the soil field water holding capacity is about 80%. Seedling sowing should be in spring soil thaw, 5 cm soil temperature stability at about 10℃ is appropriate. The treatment of seeds before sowing is the key to ensure germination. The germination rate can reach more than 80% by gently grinding 3 times with rice mill. Cover soil thickness 2~3cm, press after sowing. The core measure to ensure high yield and high quality is to select high quality transplanted seedlings. It is best to select transplanted seedlings with head diameter above 8mm and main root length about 40cm. If there are root rot fungi in the soil of transplanting site, it is easy to cause root rot after transplanting, and root dipping treatment should be carried out with fungicide before transplanting. Timely weeding is the key to seedling success, but also the key to transplanting success.