Transition to Cultivated Licorice: A Model for Chinese Herbs
In order to protect the ecological conditions of the northwestern arid areas in China, the Chinese government has halted the collection of wild licorice (Glycyrrhiza uralensis) in those regions, particularly in Inner Mongolia. These plants help stabilize the sand and retain moisture in the soil, making further collection of the plants a potential hazard to the ecological integrity of this broad area. The wild licorice supply, which has been in high demand, is now being replaced by cultivated licorice. In terms of soil, atmospheric temperature averages, and rainfall, Heilongjiang and Jilin Provinces may have the optimum conditions for the cultivation of the roots of G. uralensis.
The Anmin Licorice Production Base (ALPB) has been established in Heilongjiang Province, 100 kilometers (60 miles) from the capital city of Harbin near the border with Jilin. Anmin is a rural region in the northeastern area of the Ke-er-xin steppe. There are many poor farmers in this area who can benefit from a project involving planting licorice. The field-clearing and nursery work for this project was started in autumn of 1999. The production cycle for licorice is 3-4 years: after one year of raising the seedling in the nursery, it is grown for 2-3 years in the field to yield a mature root.
The goal of the ALPB is to assure a steady and sufficient supply of high quality licorice, prepared in slices ready for use in Traditional Chinese Medicine pharmacies and factories, and also for use as a flavoring agent suited for domestic and foreign markets. In the Anmin region, there are many households that own small plots of land, about 40 mu (approximately 5 acres; the conversion is 1 mu = 0.165 acre), for which minimum size licorice plots of about 10 mu can be developed. In order to meet the potential market for licorice roots, about 600 households have set aside a portion of their land for licorice cultivation.
Expected yields in this region are about 500-700 kg of air-dried roots per mu (about 3000-4000 kg per acre). The acreage currently being developed for cultivation is 1,000-1,300 acres (6,000-8,000 mu), with a projected annual yield of 2000-3000 metric tons (1 metric ton = 1,000 kg) a year. The maximum yield will be attained within 9-12 years, once full crop rotation is developed for this land area. If the demands for flavorings and medicines on the worldwide markets are sufficient, a maximum output of 10,000 metric tons licorice root per year can be attained at the Anmin Base area. The Anmin countryside has around 50,000 mu of land available to plant licorice (equivalent to about 8,235 acres).
To assure high quality of the roots, they are collected with a minimum 7 mm diameter and more than 30 cm in length, representing mature roots with high levels of active components. The sliced root is prepared with oblique cuts, with 10 mm diameter slices, having brown bark and yellow cortex and pith, all aspects meeting the standards of the Chinese Pharmacopoeia 2000 Edition. Further, the roots will meet the standards of unique high quality as formulated in The Goal for Production of Chinese Licorice of Unique Quality by Fu Kezhi and Fu Mining (first edition, 2000; Harbin).
The Anmin project is currently a cultivator-owned private enterprise, though joint ventures and other arrangements will be considered. ITM has invested in promoting farming for 10 plots. The costs, market values, and exchange rates may vary in the next several years while this production area is developing, it is currently estimated that the price for the dried roots will be $1.00-2.00/kg (US currency) as applied to large purchases (minimum orders of about 1,000 kg). Licorice roots collected in Autumn 2002 are displayed in the photo to the left (13-15 inches in length), with samples of slices prepared for pharmacy use shown at the top of Figure 2.
The advantages of the cultivated licorice at the Anmin countryside area:
As of autumn of 2002, the ALPB entered the second stage of development, in which enough licorice is being grown to yield of 1000-2000 metric tons a year of dried roots, and a yield of 3000 metric tons within three years. There is potential for accelerated production thereafter if demand is sufficient. Already, a customer in Seoul, Korea is taking much of the current yield, but other customers are being sought for the future larger yields. A systematic industrial technical manufacturing process for licorice has been developed at the Open Research Laboratory of Forest Plant Ecology, Northeast Forestry University in Harbin. This is a cooperative project with the ALPB, which will supply the raw materials (licorice roots) for manufacturing.
Licorice plants are prone to be harmed mainly by aphids, sometimes by beetles. In northeastern China, the damage caused by Aphis eraccivora usuana is most serious. From the first ten days of June through August, the aphid occurs in large numbers. When the air temperature reaches 22-24° C (72-75° F) and the relative air humidity reaches 90%, the amount of aphids is at its maximum. Then, when the air temperature declines below 20° C (68° F), the amount of aphids decreases rapidly. The level of damage is greatest with the youngest plants and reduces year by year as the plants mature. A solution of 2.5% decis emulsifier (a pesticide) diluted with water (1:5,000) is the best agent for killing the aphids.
The plant disease of G. uralensis in northeast China is a rust, Puccinia glycyrrhizae. Fortunately, it infects only a few of the cultivated and wild growing licorice plants, but does not cause much loss. An insect that burrows at the ground level, Porphyrophora ningxiana, has been found in Inner Mongolia; it causes heavy damage to licorice roots and rhizomes, even for wild growing licorice plants, but it has been not found in the fields of cultivated licorice as yet. In prevention and control of plant diseases and elimination of pests, organic chloride and phosphate chemicals or other agents that have a long residual time are forbidden for application in the process of licorice cultivation. Chemical weed-killing agents are also not used for licorice cultivation.
Figure 2. Cut licorice and whole stalks.