INFLUENCES OF SOIL-WATER PROPERTIES ON GROWTH OF MEDICINAL PLANT "KANZO" UNDER CONSTANT GROUNDWATER LEVEL

The medicinal plant, Kanzo (Glycyrrhiza uralensis), mainly grows on arid lands. The root of Kanzo has been compounded about 70% of herbal medicines in Japan because it has an important medicinal element. In addition, in recent years, the expansion of desertification becomes a serious problem. The cause is chiefly man activity such as over gathering plants1). The aim of this study is to prevent desertification by cultivating Kanzo with high quality. The first step is to grow Kanzo for greening. The second step is to stably produce the root with high medicinal quality. This paper presents growth properties of cultivating Kanzo by bottom watering method, which is under constant groundwater level. The main results of this paper are as follows: (1) The lower water content of cultivating soil is, the longer the root length is, (2) Growth of Kanzo is influenced by soil types, (3) Thick primary roots grow directly and vertically in low water content. On the other hand, thin secondary roots grow curvedly and horizontally in high water content and (4) Measuring evapo-transpiration velocity is the effective method to evaluate roots' growth tendency in the field.