Detailed Explanation of the Key Techniques for Artificial Cultivation of Licorice

Licorice, also known as sweet herb, is a perennial herbaceous plant of the Fabaceae family. Its rhizome is used as medicine and has a wide range of applications. In recent years, medical researchers in Japan and other countries have discovered that licorice has an inhibition rate of up to 98% against the AIDS virus and has strong immune function. The techniques for artificial cultivation of licorice are introduced below:

I. Cultivation Methods

1. Site selection and land preparation: Licorice mostly grows in dry calcareous soil. It prefers dry conditions and is cold-resistant, so it is advisable to choose loose sandy soil with a low groundwater table and good drainage for planting. In this kind of land, the main root tends to extend downward, and the roots are straight and rich in powder. After the land is selected, apply decomposed barnyard manure or compost as base fertilizer, then plow deeply to 60-100 cm, rake fine and level, and form beds 1-2 m wide.

2. Propagation: There are two methods: seed propagation and rhizome propagation. For seed propagation, spring sowing is around Grain Rain, and autumn sowing is between Start of Autumn and White Dew, but autumn sowing is better than spring sowing. The outer seed coat of licorice has a layer of mucilage and does not easily absorb water. Before sowing, the seeds must first be soaked in warm water at 40°C-50°C for about 3 days, with frequent water changes, so that the seeds fully swell. Then open furrows 20-30 cm apart, evenly scatter the seeds in the furrows, cover with 3 cm of soil, press lightly, water, and cover with straw curtains on top to keep moist; remove them immediately after germination. Use about 2.5 kg of seeds per mu. Whether seed propagation of licorice can achieve satisfactory results requires attention before and after sowing to the following: First, do a good job of deep plowing and land preparation, store water and preserve soil moisture, and expand the space for root activity. Second, sow early at the right time, sow while there is moisture, or sow early and wait for rain, promptly use soil moisture, promote rooting and germination, and increase the growth period. Third, apply sufficient base fertilizer to help accelerate seedling growth later. Fourth, strictly control sowing depth in actual operation. This is the key to emergence and seedling survival. Rhizome propagation is to select plants that have grown for many years and have many adventitious buds on the roots, dig them out in spring or autumn, use the thick roots as medicine, and cut the thin rhizomes into 15 cm pieces. Each section has 1-2 buds; dig, cut, and plant at the same time. Open furrows 15 cm deep at a row spacing of 60-100 cm, place the cut rhizomes flat along the furrows at a plant spacing of 15 cm, cover with soil, and press firm.

II. Field Management

After the seedlings emerge completely, thin them if they are too dense. Throughout the growing period, attention should be paid to loosening the soil and removing weeds. Each year, in combination with cultivating and weeding, apply topdressing 1-2 times.

III. Pest and Disease Control

1. Diseases: mainly powdery mildew and rust, mostly occurring from May to August, which can be controlled by spraying 0.3 degrees Baume lime-sulfur mixture.

2. Insect pests: mainly red spider mites, which can be controlled by spraying 1:2000 dimethoate emulsion; for cutworms, poisoned bait can be used for trapping and killing.

IV. Harvesting and Processing

Licorice has a relatively long growth period, and the harvest time can be determined according to the climatic conditions, growth, and management conditions of each region. Generally, licorice propagated by seed is harvested after 3-4 years, and that propagated by rhizome after 2-3 years. Harvesting is generally carried out in spring and autumn; digging can be done before the licorice seedlings emerge around Grain in Ear or after the aboveground stems and leaves wither around White Dew. Because different harvesting times also lead to differences in quality, that harvested in autumn is firm in texture, heavy in weight, rich in powder, and good in quality. When digging, dig out all the roots, remove mud and sand (do not wash or soak in water), and process while fresh. First cut off the branch roots and fibrous roots from the main root, then scrape off the upper knobby part, and sort into large, medium, and small grades according to root thickness and length for drying in the sun. During drying, protect from rain to avoid moisture and mildew and deterioration. Dry until half-dry, tie into small bundles, and continue drying until completely dry.