沙漠研究 22-1, 275 -278 (2012 )"ICAL 1 / DT X"

Journal of Arid Land Studies－Refereed Paper－

Comparison of Quality of Licorice (Glycyrrhiza uralensis)
under Different Groundwater Levels and Soil Conditions
Haruka KIYOTOMO*1), Kiyoshi OMINE2), Noriyuki YASUFUKU2), Taizo KOBAYASHI3),
Zentaro FURUKAWA1) and Atsushi SHINKAI1)
Abstract: The medicinal plant, Licorice, mainly grows on arid lands. The root of licorice constitutes about 70% of herbal
medicines in Japan because it has an important medicinal element called Glycyrrhizin (GC). The effects are painkiller, antifebrile,anti-inflammatory and so on. Therefore, licorice is one of the most important medicinal plants in Japan. This study especially deals
with Glycyrrhiza uralensis growing in Mongolia. In recent years, the expansion of desertification becomes a serious problem. The
cause is chiefly man activity such as over gathering plants. Licorice is also collected intensively. The aim of this study is to prevent
desertification by cultivating high quality licorice. The first step is to understand the environment where licorice grows. The second
step is to understand the environment at arid lands. And the third step is to establish a technique to control geo-environment at aridlands. Following these steps, growing licorice for greening at arid lands can be achieved. This paper presents, (1) Cultivating
licorice by bottom watering method, which is under constant groundwater level emulating desert ground environment by changing
water supply level and soil types. The experiment clarifies the mechanism of root growth. There are some influential factors onlicorice growth. (2) Investigation at Yinchuan of China, Southern Mongolia and Northeastern Mongolia. The results are watercontent, physical and chemical properties of the soil, elements of licorice’s root and GC content. (3) Comparison of the data between
cultivated at Japan and obtained at arid lands.
Key Words: Licorice, Mongolia

1. Introduction
Licorice is a leguminous plant that mainly grows on arid
lands from temperate zones to subtropics at the Northern
Hemisphere. Licorice can be used as medicine and grows at
Southern Europe, Central Asia, Inner Mongolia and Mongolia.
Especially, this study deals with Glycyrrhiza uralensis growingin Mongolia. Figure 1 shows licorice growing in a green
field at Mongolia.
Licorice has benefit components for human physiology andthe root is used about 70% as herbal medicines in Japanbecause it has many properties as painkiller, antifebrile,anti-inflammatory among others. Therefore, licorice is one of
the most important medicinal plants in Japan.
On the other hand, desertification becomes a serious
problem in a lot of places. The cause is mainly man activity
such as over gathering plants. Licorice is also collected
intensively.
The aim of this study is to prevent desertification bycultivating high quality licorice. The flow of research isshown in Figure 2. The first step is to understand theenvironment to grow licorice. The second step is toFig. 1. Licorice growing in a green field at Mongolia.

STEP1 Grasp the environment to grow Licorice
STEP2 Grasp the environment at arid lands
STEP3 Establish technique to control geo-environment at arid lands
Grow Licorice at arid lands

Fig. 2. Research flow.

understand the environment at arid lands. And the third stepis to establish technique to control geo-environment at arid
lands. By these steps, growing licorice for greening at arid

* Corresponding Author: khkrkk@yahoo.co.jp
1108-2 WEST2 744 Moto-oka Nishi-ku, Fukuoka, Japan 819-0385
1) Graduate student / Faculty of engineering, Kyushu University, Fukuoka, Japan
2) Faculty of engineering, Kyushu University, Fukuoka, Japan

3) Faculty of engineering, Fukui University, Fukui, Japanlands can be achieved. This paper presents the influences ofwater-properties on licorice using bottom watering method, theconclusion of investigation at Mongolia and China, and thecomparison between the cultivating data in Japan and the dataobtained by investigation in Mongolia.

10 cm
Horizontal
cross section

5 cm

Vertical crosssection

2. Materials and Methods
2.1. Cultivation experiment of licorice under constantgroundwater levels
In this study, the purpose is to investigate effective ways for
growing roots of licorice fast and long with high quality underarid area conditions. Licorice is dicotyledonous and has longprimary roots and secondary roots, so it is supposed that theroot of licorice grows deeply toward underground to search forwater and nutrient because the ground surface lacks of them.
Therefore, when licorice is cultivated under modelingcondition assuming arid areas, it is more effective to supply
water and nutrient from lower the roots than from the groundsurface. Therefore, licorice should be cultivated paying
attention especially to water conditions on ground.
In this experiment, pipe-shaped pot made from polyvinyl
chloride (PVC) was used for cultivation because it is easier tocontrol conditions such as soil and water conditions. The
diameter was 10 cm, and the shape of its cross section of axisdirection was semicircle. A transparent acrylic board wasattached for observing the soil conditions and roots of licorice.
Several holes for absorbing water were drilled at the bottom.
Figure 3 shows the pot shape and the way of absorbing water.
Liquid manure was stored into a container. The appliedmanure was Otsuka liquid fertilizer A-type [N:P:K:Ca:Mg =18.6:5.1:8.6:8.2:3.0 (me/l)], and it was diluted to 1/8th
concentration. Then, the pots crammed with soils were set up
in the container and potted licorice. The pot heights used inthis experiment were 30, 50, 70, and 100 cm. Figure 4 shows
the pot heights. Basically, decomposed granite soil was used,
as well as Silica sand No. 3 and No. 7 were used in 50 cm pipes
for comparison. Decomposed granite soil can be foundmainly in the western of Japan. The characteristics of eachsoil are mentioned later.
In the cultivation, there are some influential factors on thelicorice growth. This paper discusses relationships between
volumetric water content and length of roots.
2.2. Outlines of investigation
Investigations about the medicinal plant licorice wereconducted. The aim of this investigation was to understand theenvironment of licorice and the natural growth distribution inits habitat. The places and dates were (1) Yinchuan of China,
May, 2006, (2) Southern Mongolia, May, 2010 and (3)Fig. 3. Shape of the pot and bottom watering method.

Fig. 4. Used pots with different heights.

Northeastern area
Inv. On Sep. 2010

Southern area
Inv. On May 2010
Mongolia.
China

Yinchuan of China
Inv. On May 2006

© Google aap

Fig. 5. Investigation areas.

Northeastern Mongolia, September, 2010. Figure 5 shows
every place and date. All places have habitat and non-habitat
place of licorice. In the habitat, licorice grew in colonies.
Moreover, the habitat of licorice was not a complete desert but
a land like a steppe (Fig. 1).
The investigation contents were measured, as well as waterlevel at the well, sampling of soils, permeability, water content
and so on. This paper shows grain size distribution, watercontent, soil nutrients from soil analysis and GC component.

3. Results and Discussion
3.1. Grain size distribution
Figure 6 shows the grain size distribution that compares
the soils at cultivation and the Mongolian soils. Legends inthe figure are for places, soil types and pot heights. D.s.
means decomposed granite soil, and No. 3 is silica sand No. 3.
Figure 6 shows that in the cultivation experiment, decomposed
granite soil has the widest grain size distribution in comparisonGC content

8060

GC Content (%)

D.s.
No.3
No.7
No.8
Northeastern area
Southern area

40120

1

100

0.8

80

0.6

60

0.4

400.2

202000.01

0.1110100Grain size (μm)

1000

4010101520

No.3

D.s.

No.7

D.s.

Table 1. Results of soil nutrients test.
2530

samples

itemsunits

20
Northeastern area

Depth (cm)D.s.

Fig. 8. GC content and Root length of the cultivation.

Water content (%)
5030 cm 50 cm 50 cm 50 cm 70 cm 100 cm
D.s.

Fig. 6. Grain size distribution.

00

Root length

1.2

Root length (cm)Percent finer by weight (%)

10040・・

60

D.s. 30 cm
D.s. 50 cm
No.7 50 cm
D.s. 70 cm
D.s. 100 cm

80cation exchange
meq/100g・ｄｒｙ
capacity (CEC)
exchangeable base(Ca)
exchangeable base(Mg)exchangeable base(Na)
exchangeable basemg/kg・dry(K)NO3-N
avaiable P2O5
available Fe100

available SiO2

Fig. 7. Water content.

soluble Al

China
Yinchuan(Habitat)

Mongolia
South(Non-Habitat)

South(Habitat)

Japan
Northeast(Habitat)

Decomposed Silica sandgranite soil
No.7

measurement
lower limit

3.2

8.4

3.6

6.2

6.0

1.2

0.01

14000

8600

3380

1000

360

350

50590

235

92

41

360

13203285

1252254321437657

193

32

15

10.9
20880
430

1150
5100
90

33.2608100506.1
590300.84209200.71109302000.1
1011010―:under measurement lower limitof other soils. Silica sand No. 3 and silica sand No. 7 aresimilar in their slopes, but the grain size of silica sand No. 3 islarger than that of silica sand No. 7.
Next, the distribution of silica sand No. 7 is similar to that
one of the southern area of Mongolia. On the other hand, thedistribution of northeastern area of Mongolia is similar to silicasand No. 8. Silica sand No. 8 is shown as a reference. Theabove explains that the soils of Mongolia is a sandy soil andhave even grain size distribution.
3.2. Water content
Figure 7 shows water content, comparing the soils used for
cultivation with Mongolian soils in the Northeastern area, at anarbitrary depth of the ground. Legends of white dots
represent the soils at Northeastern area of Mongolia and black
dots represent the soil types and pot heights in the above
cultivation experiment. Horizontal axis means volumetricwater content (%) and vertical axis means pot depths from thesurface. The pot with Silica sand No. 3 could not bemeasured because the water content was too low to bemeasured using this sensor.
The water content in the vicinity of the ground surface at
Northeastern area has dispersion probably because of rainfall,
but the value shows around 5 % as it becomes deep. But then,water content of the soils used for the cultivation experimentshows lower value as approaching the surface. Water content

Table 2. Chemical components of roots.
items

units

Yinchuan ofChina

samplesmeasurement
Northeastern area
Kyushu-univ. Hokkaido lower limitof MongoliaCa7100

3900

4800

4700

100

Mg

2000-

1200

2000

100

Na

650-

32

109

1

K

5000

5100

7800

9200

100

Total-P

1530

-

3500

1300

10Fe

290-

230

940

10

mg/kg・dry― : unmeasured

on the pot with height of 100 cm resembles to that ofMongolian soils. The value of 100 cm was the longest
growth of roots of all conditions, but its GC content has norelation on root lengths (Fig. 8).
3.3. Soil nutrients
Table 1 is the result of analyzing soil nutrients in each
investigation area, Yinchuan of China (licorice habitat),
Mongolian southern area (habitat and non-habitat) andMongolia northeastern area (habitat). In the Table 1, twokinds of soils in Japan were described for making thecomparison. Decomposed granite soil is well distributed inWestern Japan. Silica sand No. 7 is a sand with small grain
diameter of 0.23 mm. Table 1 shows that Yinchuan of Chinaand Mongolian soil have a large amount of Ca.
Ca in soils exists not only as exchangeable cations but also
as calcium carbonates. And that influenced the results. On

It is guessed that soil nutrient cause this phenomenon.
Therefore, more analysis and examination are needed.

1412GC (%)

104. Conclusions

86420

Southern area

Northeastern area

Mongolia

Cultivation
at Kyushu-univ.
JapanGC (%)

Fig. 9. GC content.

Fig. 10.

CultivatedWild

Standard value : 2.5 %Comparison between cultivated licorice and wild one’s GC
component.

the other hand, in Japanese soils, soluble Al is highly contained.
3.4. Chemical components of roots
Table 2 is the result of chemical components of roots.
This shows that licorice root also contains a large amount of Ca.
This is due to that Ca in the soil is also high. Next to Ca, theroot contains relatively large amount of K.
3.5. GC content
GC content is measured from roots of licorice. Figure 9is the GC content that compares wild licorice at Southern andNortheastern areas of Mongolia with cultivated licorice at
Japan using bottom watering method. This Figure shows thatlicorice of Mongolia contains more GC than Japanese one.
Japanese standard value is more than 2.5% of GC content.
Almost Mongolian wild licorice satisfies the standard, butJapanese cultivated licorice does not satisfy. It is difficult tocalculate how long Mongolian wild licorice lives. Therefore
it is difficult to conclude from the data. But generally,
cultivated licorice has low GC content that it is difficult tosatisfy the standard value. The reasons are not clear. Figure
10 is a comparison between GC content of cultivated Chineselicorice and that of wild Chinese licorice.

This paper described the results of cultivating licorice underconstant ground water as well as the investigation of licorice
habitat.
The following conclusions were obtained from this study.
(1) The soil in Mongolia is composed of sandy soil with auniform grain size distribution.
(2) Water content on the pot with height of 100 cm,cultivation experiment in Japan resembles to that one inNortheastern Mongolia. The value of 100 cm was thelongest growth of roots of all conditions. But its GC
content has no relation with the roots length.
(3) The amount of the soil nutrient is greatly different in theMongolian soil and the soil used for cultivation in Japan.
The quantity of nutrients found in Mongolian soils isbigger than that of the cultivation soil.
(4) From the analysis of chemical components in the root, itwas found for that Ca is the most contained. Next to Ca,
the root contains a relatively large amount of K.
(5) GC content showed a big difference in cultivated licorice
and wild licorice.
Further cultivation experiments and studies are needed toclarify the suitable environmental conditions for growinglicorice, in order to cultivate licorice with high GC content thatcan be used as Japanese medicines.

Acknowledgement
The author would like to acknowledge financial support
from the project between Kyushu-University and Genkai town,and P&P (Kyushu University Interdisciplinary Programs
Education and Projects in Research Development).
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