Detailed Explanation of Licorice Seedling Raising Methods and Key Planting Techniques
Abstract: Licorice is the source material for a large number of traditional Chinese medicine preparations, and is widely used in food, beverages, tobacco, daily chemicals and other fields, with broad application prospects. However, due to the lack of wild licorice resources, artificial planting efforts need to be increased. In order to improve licorice seedling raising and planting techniques, the Urumqi Grassland Station conducted licorice seedling raising and planting...
Abstract: Licorice is the source material for a large number of traditional Chinese medicine preparations, and is widely used in food, beverages, tobacco, daily chemicals and other fields, with broad application prospects. However, due to the lack of wild licorice resources, artificial planting efforts need to be increased. In order to improve licorice seedling raising and planting techniques, the Urumqi Grassland Station conducted licorice seedling raising and planting trials, and the seedling raising and planting techniques are introduced as follows.
Chinese Library Classification Number: S54 Document Identification Code: B
Article Number: 1003-4889 (2007) 04-0046-02
Licorice is an excellent leguminous forage grass, mainly produced in Inner Mongolia, **, Gansu, Ningxia and other places in China, and is one of the important resource plants of the western region. Licorice has excellent characteristics such as cold resistance, heat tolerance and saline-alkali resistance, with strong adaptability and vigorous vitality; licorice also has extremely high nutritional value, with a crude protein content of 14.08%, similar to that of alfalfa (purple clover) and the xerophytic leguminous forage caragana (Caragana korshinskii), and 2.10% less than sainfoin; while its crude fat content is 3.45%, 4.49% and 3.55% higher than that of alfalfa, sainfoin and caragana respectively, and its crude fiber content is correspondingly reduced by 1.65%, 6.88% and 11.58%, and its output return is slightly higher than that of alfalfa. With in-depth research on licorice, new uses for licorice are changing with each passing day, entering people's daily life, and it is widely applied in food, beverages, tobacco, cosmetics, chemicals, brewing, national defense and other industries, with market demand growing day by day. The price has also risen from 700 USD/t in 1981 to 3000 USD/t now. But for many years, 80% of the licorice sold by people was wild, and reckless digging and indiscriminate harvesting not only severely damaged China's natural grassland resources and caused large areas of soil desertification, but the distribution area of wild licorice has also been declining sharply. For this reason, the State Council issued a notice prohibiting the harvesting and sale of Nostoc flagelliforme and stopping the reckless digging and indiscriminate harvesting of licorice and ephedra, implementing special management of licorice and ephedra and increasing investigation and punishment efforts. It is obvious that to solve the contradiction between the supply and demand of licorice and the export of licorice products and China's environmental protection, the most critical thing is to vigorously promote and support the development of artificial licorice planting. At the same time, improve planting techniques and increase licorice yield.
1. Sowing Methods
1.1. Land Selection and Preparation
Licorice has wide adaptability and does not have strict requirements for the cultivation environment. It can be cultivated in semi-arid and arid areas with an average temperature of 4-12°C and sunshine hours of more than 2 600h, and licorice can also be planted on barren farmland returned from cultivation. However, attention should also be paid to the fact that waterlogged lowlands and areas with high groundwater levels, as well as areas with heavy and slightly acidic soil, are not suitable for planting licorice. Where conditions permit, it can be planted on sandy or water-quality soil with a soil salt content not exceeding 0.5%, which can achieve the goals of high germination rate and seedling survival rate, fast growth speed, bright color of roots and rhizomes, good quality and high economic benefit. The Urumqi Grassland Station selected the trial site on a plot in Yongfeng Township that had been planted with wheat 3 years earlier and then left fallow, with deep soil layers, loose soil texture, good drainage and low salinity and alkalinity. Early field treatment included: deep plowing 40-50cm, raking fine and leveling, making high ridges with a ridge width of 40-45cm and a ditch width of 30-35cm. The trial area was 3hm2. 1.2 Seed Selection and Seed Treatment
1.2.1. Seed selection: Ural licorice (Glycyrrhiza uralensis) with relatively high contents of glycyrrhizic acid and glycyrrhetinic acid was selected.
1.2.2. Seed treatment: Licorice seeds have a hard seed coat, are impermeable to water and air, and are not easy to germinate. The germination rate of untreated seeds is only 30%-40%, while the germination rate after seed coat breaking treatment can reach more than 90%, so the seeds must first be pretreated before sowing. The method used was: soak the seeds in water at 60°C, remove them, cover them with a wet cloth for 4-6h to allow them to absorb water and swell, then dry them in the sun and drain them before sowing.
1.3. Sowing and Seedling Raising
Licorice can be sown in spring, summer and autumn, but according to the climatic conditions of the Urumqi area, the yield and quality are better in spring. The trial area was chosen for sowing in mid-April in spring. A 12-row seeder was used for drilling, with a sowing depth of 2-3cm and a row spacing of 30cm. To increase yield, the sowing rate was increased to 12kg/hm2. When sowing, it is necessary to ensure uniform seed distribution and consistent depth, and after sowing, appropriately compact the soil and irrigate once.
At an air temperature of 20°C, seedlings can emerge in 5-7 days. When 50% of the seedlings have emerged, remove the covering grass, water to preserve soil moisture, and wait for full emergence. When the seedlings are 15-20cm high, the emergence rate is 90%, the seedlings grow for about 4 months, and the roots reach 35-40cm, meeting the requirements of the transplanting standard.
1.4. Field Management
1.4.1. Thinning and final singling of seedlings: Thin the seedlings when the young plants grow 1-2 true leaves, keeping the seedling spacing at about 5cm, and finalize the seedlings when the plants grow 3-4 true leaves, with a plant spacing of 10-15cm.
1.4.2. Irrigation: Although licorice is a deep-rooted drought-resistant plant, its drought resistance is not strong at the seedling stage because the roots are relatively shallow. Therefore, after the seedlings grow to 4 true leaves, water them for the first time, using fine shallow flow irrigation or sprinkler irrigation, and do not use flood irrigation. Pay attention to keeping the seedlings moist; the number of waterings should be neither too many nor too few, so as to ensure the water supply during the seedling stage. After the adult plant stage, little watering is needed. In July-August when there is a lot of rain, drain promptly so that there is no standing water in the field and root rot is prevented. The key to cultivating licorice is preserving seedlings; generally, no more watering is done after the plants have grown.
1.4.3. Intertillage and weeding: After the seedlings have emerged completely, intertillage and weeding should be carried out promptly so that there are no weeds in the field; this is the key to high quality and high yield. Where conditions permit, closed weeding can be carried out after sowing and before seedling emergence, spraying the field with 2 bags/667m2 of douhuanglong (20% chlorimuron-ethyl) wettable powder and 2-4 bottles/667m2 of acetochlor. After seedling emergence, herbicides that kill monocotyledons can be sprayed to eliminate weeds.
1.4.4. Topdressing: The first topdressing is carried out after final singling of seedlings, applying 10kg of urea per 667m2 in furrows. The second topdressing is applied when the seedlings are 20cm high, with 15kg/667m2 of urea. Foliar fertilizer can also be sprayed to increase yield.
2. Disease Control
The main diseases of licorice are powdery mildew, gray leaf spot and rust. Therefore, field management should be strengthened, attention should be paid to drainage, and ventilation should be maintained. If disease occurs, spray with a 1000-fold solution of triadimefon at the early stage of the disease, or use 0.3 Baume degree lime-sulfur mixture, or 75% chlorothalonil wettable powder 500-600-fold solution, spraying once every 7-10 days, and 2-3 sprays are sufficient.
3. Rough Calculation of Economic Benefits
The market price of licorice is 5-6 yuan/kg (fluctuating up and down with market price changes, generally around 30%). For seedling transplanting cultivation, the expected yield after growth is 600-800kg/667m2 (the yield will be lower than this if management and harvesting are not standardized), and the income is 3000-4800 yuan/667m2. Investment per 667m2: 600 yuan for seeds, 200 yuan for fertilizer (base fertilizer plus topdressing), 10 yuan for pesticides, 50 yuan for plowing (twice), 60 yuan for labor, 100 yuan for water fees, 30 yuan for others, totaling 1 050 yuan; net profit per 667m2 is 1 950-3750 yuan, calculated over two years, income per 667m2 is 900-1800 yuan, with good economic benefits and it can be vigorously promoted.