沙漠研究 22-1, 25 -28 (2012 )"ICAL 1 / DT X"

Journal of Arid Land Studies－Refereed Paper－Field Surveys of Soil Conditions in Steppe of Northeastern Mongolia
Taizo KOBAYASHI*1), Atsushi Shinkai2), Noriyuki YASUFUKU2), Kiyoshi OMINE2),
Atsushi MARUI3) and Tomoaki NAGAFUCHI3)
Abstract: Licorice (Glycyrrhiza) is among the world's most ancient herb. It is a temperate-zone herb but grows wild also in arid
lands including northern China, Mongolia and central Asia. Recently, it is said that overharvest of licorice have been leading to theland deterioration and/or desertification. As a final goal of this study, we are attempting to develop a cultivation technique ofhigh-quality licorice which can bring a solution for a stable supply of licorice as well as for countermeasure against the desertification.
As a first step for establishing the licorice cultivation technique, field surveys were carried out in natural growth areas of southern andnortheastern Mongolia. The surveys were conducted focusing on subsurface conditions where licorice grows to find the soil
condition which is suitable for growing high-quality licorice. This paper presents results of the measurements; grain size distribution,water content, chemical composition and electric conductivity, etc. Licorice roots collected in the fields contain high concentration of
the active ingredient called glycyrrhizin, indicating that the soil conditions made clear from the investigations will provide a clue to asolution for establishing the cultivation technique of high-quality licorice.
Key Words: Field survey, Licorice, Mongolia, Soil condition, Steppe.

1. Introduction

Fig. 1. Licorice (Glycyrrhiza uralensis).

Resources of Licorice in Bayanhongor (ton)Licorice (Glycyrrhiza) is among the world’s most ancientherb. Licorice is a leguminous plant and its roots contain anactive ingredient called glycyrrhizin that have been used infood, medical remedies and cosmetics, etc (Fig. 1). It grows
wild in arid land, including northern China, Mongolia and othercentral Asian countries, as well as in some temperate-zones in
Europe. Licorice has an extensive branching root system andits taproot extends deep in the ground. The roots are
harvested by generally digging deep holes in the ground,indicating that the harvest can damage the land if backfilling is
not carried out. It is a problem that most of the licoriceproduction has been intended for wild resources, and thus, theoverharvest leads to not only a decline in the wild licorice but
also a cause of land degradation and/or desertification of thenatural growth area. Figure 2 shows the change of licorice
resource in Bayankhongor province (see Fig. 4) in Mongolia.
It is evident that the resource has drastically decreased from1980s to 2000s. Recently, China, one of the main country oforigin, has restricted the export of licorice. This restriction
have brought a serious situation in wide range of diverse
industries in Japan.
The final goal of this study is to develop a cultivation
technique of high-quality licorice which can bring a solution
for a stable supply of licorice as well as for countermeasureagainst the desertification. As a first step for establishing thelicorice cultivation technique, field surveys were carried out in7000

Estimated reserves
Productive resource

6000
5000
4000
3000
2000
1000
01985

2006

Year2009

Fig. 2. Change of licorice resource in Bayankhongor province inMongolia.

* Corresponding Author: tkoba@u-fukui.ac.jp
3-9-1 Bunkyo, Fukui 910-8507 Japan
1) Faculty of Engineering, University of Fukui, Japan

2) Faculty of Agriculture, Kyushu University, Japan

3) Faculty of Engineering, Kyushu University, Japannatural growth areas of southern and northeastern Mongolia forthe purpose of making clear the soil conditions where wildlicorice grows.
Mongolia

2. Field Surveys in Mongolia

Bayankhongor

Fig. 4. Survey area map.

16Max

1412

GL content (%)

Mongolia is one of the countries that high quality licorice
grows in wild. In 1985, a Russian-Mongolian joint team had
achieved a large-scale field survey that aimed to make alicorice vegetation map in Mongolia. They reported that wildlicorice distributed in mainly four regions (see Fig. 3(b));
northeastern region (grassland and steppe), northwestern region(semidesert and flood plain), western region (semidesert andplain), and southern region including Bayangkhongor province(semidesert and plain-oases, accounted for 84% of the whole
distribution).
As shown in Figure 3 (Hilbig, 1995; Van Staalduinen andWerger, 2005), going from north to south aridity increases
together with decrease of the mean annual precipitation. The
zoning of the vegetation corresponds rather well with thegradient of decreasing precipitation from north to south. It is
can be seen that licorice can grow in harsh environment, suchas a land where the annual precipitation is less than 100 mm.
In this study, field surveys were conducted in southern andnortheastern regions shown in Figure 4. Objectives of thesurveys are to update a licorice vegetation map and to makeclear the soil conditions where licorice grows wild. The108675%

Max75%
50%
Min 25%50%

420MinSouthern area

25%

Northeastern Area

Fig. 5. Glycyrrhizin (GL) contents in collected licorice roots.

surveys were conducted in May 2010 (in the southern area) andSeptember 2010 (in the northeastern area) by a joint researchteam of Kyushu University and the Mongolian Academy ofScience (Institute of Botany).

3. Survey Results and Discussions(a) Mean annual precipitation in Mongolia (Hilbig 1995)
Northwestern region(413 ton/116 ha)

Northeastern region(391 ton/306 ha)Western region(1884 ton/229 ha)

3.1. Glycyrrhizin (GL) contents in collected licorice roots
The Japanese Pharmacopoeia XIV (JP XIV) requires that
Glycyrrhizae Radix for medical use should contain not lessthan 2.5% of glycylrrhizin (GL) (Yamamoto and Tani, 2002).
Figure 5 shows the GL contents of wild licorices collected in
the surveys. Although variation arises especially in samplesof the northeastern area, it is seen that they have GL content ofaround 8% on average. It is said that licorice can be greweasily, but the GL content doesn't exceed the reference value
easily. This results indicate that the environments including
soil conditions of the natural growth areas in Mongolia hold thekey to cultivating high quality licorice.

Southern region(14470 ton/528 ha)(b) Vegetation zones of Mongolia (after Wallis de Vries 1996)
Fig. 3. Precipitation and vegetation map in Mongolia.

3.2. Physical properties of the soils
Figure 6 shows the typical grain size distributions collectedin natural growth areas in a southern and northeastern survey
points. For reference, a grain size distribution of a weathered

Volumetric water content (%)

100SouthLong: 100o 41' N
Lat: 45o 05' E
Northeast
Long: 113o19' N
Lat: 48o 14' E
Weathered grinite soil
Fukuoka, Japan

60
40246810100

101

16182060
80South area (habitat)
Northeast area (habitat)
Northeast area (nonhabitat)

100
10-1

1440

200 -2101220Depth (cm)Percentage finer by weight (%)

80

00102

103

104105120

Grain size (µm)

Fig. 8. Volume water content versus depth.

Fig. 6. Grain size distributions.

110100Depth (cm)20406080100120South area (habitat)
North-east area (habitat)
North-east area (nonhabitat)

Amount of elution (mg/kgdry)

03500
3000
2000

Mean grain size (D50) (µm)

South area
Northeast area
Silica sandCompost

1500
1000
500
0Ca

Mg

NaNO--3-NP

K

Chemical composition (mg/kgdry)Fig. 9. Chemical compositions of the soils.

Fig. 7. Mean grain size versus depth.

grinite soil sampled in Fukuoka Japan is also plotted in thegraph. The southern investigation site is on semidesert zone
and the northeastern site is on steppe zone. The soil in thenortheastern steppe zone can be categorized as Loam and/orSilt loam and is finer than that in the southern semidesert zone.
The soil in the semidesert zone is categorized as sand and has apoorly graded gradation.
Figure 7 shows variations of mean grain size (D50) withrespect to the depth. There seems to be a general trend thatthe grain size becomes slightly smaller with depth. Althoughdata obtained from the northeastern site is plotted by separating
it into habitat and nonhabitat in this graph, a difference in thegrain size cannot be seen clearly. It appears that finer grains
are suited for the growth of licorice but the grain size, in termsof a physical property, will not be a major factor.
Figure 8 shows variations of volumetric water content withrespect to the depth. It is seen that discrepancies appear inshallow zones (up to around 20 cm deep) but the variations
converge to a narrow range with increasing depth. It is ofinterest to note that the water contents below the grounds lie in
the narrow range, between approximately 2 and 6%, regardlessof the grain size. Also, noteworthy is that the soils containsimilar low water contents regardless of the climate; thesouthern and the northeastern site are located in semidesert andsteppe zone, respectively. Compared to general cultivatedlands, this range of water content is low, therefore, soil moisturecontrol will play a important role to cultivate high quality
licorice. Note that matric suction is dependent on soil
characteristics even if the soil have the same water content.
Further investigation is needed to make clear the detailed
root-soil interactions systems.
3.3 Chemical properties of the soils
Figure 9 shows chemical compositions leached from thesoil samples. For reference, test results for a manufactured
silica sand and a compost were also shown in the graph. It is
obvious that the soil in the southern site (sandy soil) contains
extremely high calcium (Ca). In general, sandy soils have
low levels of calcium and tend to be acid, because sandy soils

pHMax

975%

7Min

75%
50%

Max

50%

25%
25%
Min

10Max
50%

56

Min

25%

South Northeast

75%

50%
25%

0CEC

4. Conclusions875%

EC (mS/m)

pHMax

81510EC

CEC (meq/100gdry)

2010MinSouth Northeast6Max42075%
Min25%SouthFig. 10. pH, EC and CEC of the soils.

quickly lose their calcium content by water drains (this isevident in Figure 9 that the silica sand contains low Ca
compared to others). It seems that rare precipitation results in
the Ca accumulation in the sandy ground. Figure 9 also
shows that the soils of the semisedert and steppe zones havelittle other nutrients contained, suggesting that licorice cangrow up even in such unbalanced low-nutrition soils.
Figure 10 shows the results of pH, Electro Conductivity(EC) and Cation Exchange Capacity (CEC) of the collected
samples. Both of the soils shows alkalinity and the average isaround pH = 8. This seems to be attributed to the high Ca
content. There is a trend that the soil EC of the southern site
(sandy soil) exceed that of the northeastern site (silty soil)
although finer soils generally tend to have higher EC values.
The CEC value of the southern site seems to be quite low
compared to general cultivated soils. By adding certain
amount of calcium to a manufactured silica sand, it may bepossible to create a soil which is suited for the Licorice
cultivation. It goes without saying that further examinations
from various viewpoints requires to establish a promisingcultivation technique, however, the findings from the surveys
will provide a clue to the solution.

This paper presents results of field surveys in a semidesert
and a steppe zone of Mongolia. The surveys were carried out
to find the physical and chemical conditions of soils that issuitable to the growth of high quality licorice. The findings ofthe surveys are summarized as follows:
1) It is confirmed that a high quality licorice grows wild inthe southeastern semidesert and the northeastern steppezones in Mongolia and the active ingredient (glycyrrhizin)
content is about 8% on average.
2) The licorice grows in Sand, Loam and Silt loam with thevolumetric water content of 2 - 6%.
3) The semidesert and steppe zones investigated contain highcalcium and so the soil trends to be alkaline (the soil pH isaround 8 on average).
4) The soils have little other nutrients contained, suggestingthat licorice can grow up even in such unbalanced
low-nutrition soils.
Acknowledgement
This research was partly supported by the Ministry ofEducation, Science, Sports and Culture; Grant-in-Aid for
Scientific Research (A) (No. 22246064).
References
Hilbig W. (1995): The vegetation of Mongolia. SPB Academic
Publishing, Amsterdam.
Van Staalduinen M.A., Werger M.J.A. (2005): The steppes ofMongolia. The impact of herbivores in a Mongolian
forest steppe. Febodruk BV.
Yamamoto Y., Tani T. (2002) Growth and glycyrrhizin
contents in Glycyrrhiza uralensis roots cultivated for fouryears in eastern Nei-Meng-gu of China. J. Trad. Med.,
19(3): 87-92.