Detailed Explanation of Key Techniques for Licorice Seedling Raising and Transplanting

Licorice is an important medicinal herb. With the strengthening of national ecological and environmental protection, the use of wild resources has become very limited, and licorice seedling raising and transplanting techniques have become very important.

Licorice is a perennial herbaceous plant of the Fabaceae family and is listed by the state as a key specially controlled medicinal herb. As a sweetener, glycyrrhizic acid is 200-300 times sweeter than sucrose and is the best natural sweetener discovered to date. The state has explicitly designated licorice as a national Class II protected plant, and random digging is not permitted, which has intensified the contradiction between supply and demand of licorice. Therefore, research on artificial cultivation and high-yield, high-quality cultivation techniques is of great significance.

1 Morphological Characteristics

The licorice plant is 50-120 cm tall. The root is thick and large, cylindrical, and reddish-brown. The rhizome grows horizontally, and its shape and color are similar to the root. The stem is upright, with pinnately compound leaves arranged alternately, 7-17 leaflets, ovate or elliptical. The flowers are papilionaceous, light purplish-red. The pod is curved, sickle-shaped, with external bristles. The seeds are round, brownish-green, with a 1000-seed weight of 7 grams. The flowering period is July-August, and the fruiting period is August-October.

2 Growth Habits

Licorice is mainly distributed in the "Three North" regions of China. It has low soil requirements. It prefers weakly alkaline sandy land, grassland, sand dunes, riverbanks, and desert and semi-desert environments. When introduced to the black soil of grain-producing areas, it grows vigorously and shows high yield and high quality.

3 Land Selection and Sowing

For artificial cultivation of licorice, seedling raising and transplanting is best, that is, first raise seedlings in a nursery for 1 year, then transplant the seedlings into the field in that autumn or the following spring. Raising seedlings for 667 sq m can transplant 5-7 mu (667 sq m). Compared with direct sowing in the field, seedling raising and transplanting has the advantages of a higher rate of Grade I and Grade II finished products and less labor for harvesting, and is a new-type cultivation technique with high yield and high efficiency.

Licorice is a deep-rooted plant. Land with fertile soil, loose texture, good drainage, and rich organic matter should be selected for planting. Land preparation should involve deep plowing to 40 cm, and at the same time, 3 cubic meters of high-quality farm manure and 20 kg of diammonium phosphate should be applied per 667 sq m as base fertilizer. Then form ridges 65 cm wide, press them, and wait for sowing. Sowing and seedling raising can be done in spring, summer, or autumn. Spring sowing is from Qingming to Guyu, summer sowing is from Lixia to Xiaoman, and autumn sowing is carried out before the ground freezes, with seedlings emerging the following spring. The sowing method is to open a 20 cm wide furrow on the ridge surface with a plow, level it after plowing, have workers tread the grid, and use a seed gourd to evenly sow seeds soaked in fungicide on the ridge surface, cover with about 2 cm of soil, and then press. Sow 5-8 kg per 667 sq m; with good soil moisture, full seedlings can emerge in about 10 days. To prevent weed damage, trifluralin herbicide can be sprayed on the ridge surface before sowing, and it is advisable to use 1/5 of the dosage stated in the instructions per 667 sq m; sow 6 days after spraying.

4 Seedling Field Management

After licorice seedlings emerge, frequently inspect the field for dead seedlings. If present, use 100 g of thiophanate-methyl powder plus 250 g of urea per 667 sq m, add 50 kg of water, fully dissolve, and spray on the seedling leaves, which can effectively prevent seedling death. If missing seedlings or broken rows appear, replant as early as possible to ensure full stands in the field. When licorice has grown 4-6 true leaves, apply a topdressing of urea once along the furrows in combination with intertillage, 10 kg per 667 sq m. At 10 leaves, as the temperature rises, field weeds begin to grow vigorously, so hoe and cultivate frequently, generally 3 times. When weeds are severe, spray 150-200 g of sethoxydim per 667 sq m, which can effectively eliminate grass weeds; the remaining broadleaf weeds can be removed by hand. Seedling fields are not thinned, maintaining 100,000-120,000 plants per 667 sq m. When licorice has 15 true leaves, green caterpillars may occur; use 100-200 g of methamidophos per 667 sq m diluted with water for foliar spraying. If aphids occur, use 100 g of omethoate diluted with water for spraying. When both insects occur at the same time, the two pesticides can be mixed and sprayed together.

After licorice closes its rows, pay attention to pulling out large weeds in the field early. During the rainy season, drain standing water in the field in time to prevent soaking the licorice and causing root rot. According to surveys, wild licorice has diseases such as powdery mildew and rust, but these diseases have not yet occurred in many years of artificial cultivation.

5 Field Transplanting

Transplanting in that autumn gives higher yield than transplanting the following spring. When transplanting, leave a 5 cm stubble and horizontal stem above the root crown of the dug-out roots, and transplant immediately after digging. Do not cut the seedlings and plant them upright, and it is even more impermissible to cut off the overwintering buds and fibrous roots of the root crown. Open furrows 10 cm deep with a plow, and the licorice roots can be planted horizontally, obliquely, or flat. The plant spacing is 10 cm, cover with soil 10 cm deep, and press to preserve soil moisture. Plant 18,000-22,000 plants per 667 sq m. If conditions permit, it is best to water once before freezing to settle the roots. A series of field management measures such as land preparation, fertilization, and pesticide application before and after transplanting are the same as for seedling raising. Autumn planting is carried out after the autumn harvest, and spring planting is around Qingming.

6 Harvesting and Processing

Licorice can be harvested in the autumn of the second year after transplanting, generally yielding 800-1000 kg of dry goods per 667 sq m. In October, lift and harvest with a plow, remove the soil, tie into small bundles according to different grades of soil roots, lateral roots, and branch forks, and dry in the sun for sale. It can also be harvested the following spring before sprouting.

7 Market and Benefits

Because wild licorice resources are decreasing year by year and artificial planting has just started, prices are rising frequently. Licorice is one of the ten best-selling natural medicinal plants in the current US market. It can be said that licorice is a "green bank" that saves money (low input), saves land (can use sandy wasteland and saline-alkali land), saves labor (extensive management), and has high benefits (supply falls short of demand). Planting licorice is truly high-efficiency agriculture. If planted on a large scale, it can also be processed into licorice paste, glycyrrhizic acid, and other by-products, and the profits will be even greater.