Detailed Explanation of Key Points for High-Yield Cultivation Techniques of Licorice

Licorice is also known as sweet grass root, sweet licorice, sweet root, powder grass, etc. It is a perennial herb of the genus Glycyrrhiza in the Fabaceae family, with its roots and rhizomes used as medicine. It is sweet in taste and neutral in nature, and has the effects of clearing heat and detoxifying, moistening the lungs and eliminating phlegm, tonifying the spleen and replenishing qi, relieving cough and resolving phlegm, and harmonizing various medicines. It is used for sores and ulcers, detoxification, cough and sore throat, weakness of the spleen and stomach, qi deficiency and insufficient blood, common cold, stomach pain, limb pain, jaundice, periodontal disease and other conditions. In addition, Glycyrrhiza glabra, Glycyrrhiza aspera, Glycyrrhiza inflata, Glycyrrhiza eurycarpa, Glycyrrhiza pallidiflora, Glycyrrhiza eurycarpa, and Glycyrrhiza yunnanensis are also used as licorice. The licorice plant height is 40-120 cm, the rhizome is cylindrical, mostly growing horizontally, the main root is long and thick, cylindrical, the outer bark is brownish-red, the interior is yellow, the leaves are sweet, the stem is erect, and the lower part is lignified. The leaves are alternate, odd-pinnate compound leaves, with 5-17 leaflets, ovate-elliptic, 25 cm long, 2 cm wide, entire margin, both sides pubescent. The raceme is axillary, the flower is papilionaceous, light purplish-red. The pod is flat, mostly clustered into a spherical shape. The seeds are broadly elliptic or round, slightly flat, 2.7-4.3 mm long, 2.6-3.7 mm wide, 1.8-2.3 mm thick, the surface is dark green, brownish-green, brown or brownish-brown, smooth, slightly glossy. The thousand-grain weight is 7 grams. The flowering period is June-July, and the fruiting period is July-September. The main key points of high-yield cultivation techniques for licorice are as follows:

1. Soil Selection

Licorice has well-developed rhizomes, deep penetration into the soil, is suitable for dry farming, tolerant of salinity and alkalinity, afraid of waterlogging, and has very strong vitality. For cultivating licorice, it is better to choose sandy soil with a low groundwater level, good drainage conditions, deep soil layer, pH 7-8, and convenient irrigation. Plowing is best done in autumn; spring plowing is also acceptable, but soil moisture must be ensured, clods broken up, and the ground leveled, otherwise it will affect full seedling emergence and strong seedlings. Poor barren degraded farmland can also grow good licorice.

2. Variety Selection and Seed Treatment

In our province, Glycyrrhiza uralensis is generally selected as the main variety. Before sowing, the seeds are ground with an electric rice milling machine, and soaked in hot water at 35-40 degrees C for 3-4 hours. Alternatively, weigh the seeds and place them in a ceramic jar, mix the seeds with 30 ml of 80% concentrated sulfuric acid per 1 kg of seeds, seal and treat at 20 degrees C for 7 hours, then rinse repeatedly with clean water and dry for later use.

3. Sowing

Licorice can be sown in all three seasons: spring, summer, and autumn. In places with good soil moisture in spring, spring sowing is mostly used, generally no later than mid-April. Spring-sown licorice has a long growing period in the same year, and the root body penetrates deep into the soil. In some places where spring is dry and it is difficult for seedlings to emerge after sowing or difficult to preserve seedlings after emergence, summer sowing should be carried out. Summer sowing should be done before the rainy season arrives, which is beneficial for seedling emergence and seedling preservation. In recent years, some places sow at the turn of autumn and winter; after sowing, the seeds do not germinate and the soil freezes, and when the soil temperature is suitable the following year, they germinate and emerge. Because the soil moisture is good, the seedling emergence and seedling preservation rates of licorice are both high. Before sowing, apply 4000 kg of high-quality farmyard manure per mu and 35 kg of ammonium phosphate per mu as base fertilizer. Prepare the land into small beds, and water sufficiently for bottom moisture before sowing. Evenly broadcast or drill the seeds, using 10-15 kg of seeds per mu. Cover with soil 2.5-3 cm, not too deep. Seedlings emerge after 7-10 days.

4. Transplanting

The flat planting method is used. In the autumn of the same year, after the licorice leaves turn yellow and wither, cut the aboveground parts for cattle and sheep feed. Then plow the soil 30 cm, dig out roots more than 25 cm long, and use smooth straight roots as transplanting material. Cover with 5 cm of soil for temporary planting and storage. Carry out in the autumn of the same year or the spring of the following year. Plow furrows 5 cm deep, with a row spacing of 33 cm and a plant spacing of 15 cm, place the seedlings flat in the furrows and cover with soil. Or use a shovel to dig furrows for transplanting. Plant 12,000-15,000 seedlings per mu. Licorice that has undergone seedling raising and transplanting grows quickly and can be harvested in autumn, generally yielding 500-700 kg per mu. Harvesting in the second year is best, and the yield per mu can reach 1000 kg.