沙漠研究 24-1, 113-116 (2014)
Ἃ₍◊✲ 24-1, 113 – 116 (2014)
Journal of Arid Land Studies
Journal of Arid Land Studies－ DT11 Refereed Paper －㸫DT11 Refereed Paper㸫

Relationships between Soil Water / Calcium Environment and Growth ofLicorice (Glycyrrhiza uralensis)
Zentaro FURUKAWA*1), Noriyuki YASUFUKU 2), Kiyoshi OMINE 3), Atsushi MARUI 4) and Ren KAMEOKA 1)
Abstract: Desertification is one of the most remarkable global environmental problems. This paper investigates opportunities tocombat desertification utilizing the medicinal plant licorice (Glycyrrhiza uralensis). Licorice natively lives in arid region such as
Mongolia and China, although the numbers of individuals are decreasing due to excessive harvesting, overgrazing and decreasing
groundwater levels caused by unstable rainfall, ultimately leading to increase desertification. Due to these facts, licorice was pickedup as a “precious genetic resource” at COP 10 (Conference of the Parties, Convention on Biological Diversity) because there is a
supply shortage of licorice as herbal medicine. Therefore, there may be anti-desertification opportunities through the development ofa planting method for licorice in arid ground, especially those areas of extreme desertification where other crops are not grown.
Furthermore, if the method is given to local people, it will provide value-added greening. This means that the method will contributeto anti-desertification while also decreasing the supply shortage of licorice and stimulating the local economy. As the fundamental
research to accomplish these purposes, the relationships between soil water environment, soil saline environment and growth oflicorice should be determined. This paper examines the function of “greening soil material” (i.e. commercial compost) on the growthof licorice in a cultivation experiment. And the evaluation method about relationships between soil water environments, soil salineenvironment, especially calcium concentration, and the growth of licorice were examined by using greening soil material and imitatingarid ground.
Key Words: Desertification, Licorice (Glycyrrhiza uralensis), Soil saline environment, Soil water environment

1. Introduction
Desertification is accelerated by climate change, excessiveplant harvesting and over grazing and is one of the most urgent
global environmental problems (UNEP, 1992). This paper
examines methods of combating this problem by utilizing
medicinal plant licorice (Glycyrrhiza uralensis, Fig. 1).
Licorice natively lives in arid regions such as Mongolia andChina, although the plant’s population is decreasing due toexcessive harvesting, overgrazing and decreasing groundwaterlevels caused by unstable rainfall (Shoyama, 2002). These
factors are leading to increasing desertification. Due to thesefacts, licorice was identified as a “precious genetic resource” at
COP10 (Conference of the Parties, Convention on BiologicalDiversity) because there is a supply shortage as herbal
medicine. Therefore, there may be anti-desertification
opportunities through the development of a planting method
for licorice in arid ground, especially in those areas of extreme
desertification where other crops are not grown. Furthermore,
if the method is given to local people, it will provide
value-added greening. This means that the method willcontribute to anti-desertification while decreasing the supply* Corresponding Author: soil36civil@yahoo.co.jp

Fig. 1. Habitat of wild licorice and root of licorice.

shortage of licorice. In order to accomplish these purposes, it
is important to understand the relationships between soil water
environment, soil saline environment and growth of licorice.
In this paper, we identify the function of “greening soilmaterial” (compost), shown in Figure 2, which can supply
significant water and nutrition to young licorice due to its highwater and nutrient holding capacity. The cultivation
experiment in Mongolia and Japan using greening soil material,
which used evaluation methods to quantify the relationships
between soil water environment, soil saline environment,
especially calcium concentration, and growth of licorice, areconsidered to suggest suitable soil water and nutrient conditions.
㸦Received, September 9th, 2013; Accepted, February 20th, 2014㸧

744 Moto-oka Nishi-ku, Fukuoka, Japan 819-0385
1) Graduate student/faculty of engineering, Kyushu University, Fukuoka, Japan

3) Faculty of engineering, Nagasaki University, Nagasaki, Japan

2) Faculty of engineering, Kyushu University, Fukuoka, Japan

4) Faculty of agriculture and life science, Hirosaki University, Aomori, Japan114
100

Arid groundPercent finer by weight (%)

Licorice
Greenigmaterial

Lowwater/nutrient
holding capacity
Promotion of growth of root
Growndwater level

Highwater/nutrient
holding capacity

604000.01

Depth (cm)100150

pH-Potting compost (J)Non-Habitat 1(45㼻
36' 37" N, 99㼻
36' 45" E)
Habitat 1 (45㼻
36' 35" N, 99㼻
36' 43" E)
Non-Habitat 2 (45㼻
09' 14" N, 100㼻48' 42"E)
Habitat 2 (45㼻
07' 13" N, 100㼻
51' 11" E)

Table 1. Propagation test results in Non-Habitat (Furukawa, 2013).
RhizomeSeeds
䠄Vertical䠅（Vertical）
Case-1 0%
Case-2 20%--Rhizome
䠄Horizontal䠅
（Horizontal）
50% (5cm is failed,10cm, 20cm is succeeded )2. Materials and Methods
2.1. Verification of efficacy of greening method for
cultivating licorice
In order to confirm the effects and appropriateness ofgreening soil material in arid ground, a cultivation experiment
was conducted in Non-Habitat 1 (45°09’14”N, 100°48’42”E),
Bogd, Mongolia, shown in Figure 3 (Furukawa et al., 2013).
Annual precipitation of these areas is about 100-200 mm.
The planting depth and direction of the materials (vertical /horizontal) were varied, and propagation rates were confirmed
nine month after the start of experiment. As shown in Table
1, propagation rate from seeds was 0%, but 20% to 50% ofrhizomes were successfully propagated in each condition.
These results may be due to the water and nutrient holding
capacity of greening soil materials. In order to confirm thedetails of effects of greening soil materials on plant germination

ECCEC
mS/cm meq/kgdry

10.26

0.24

5.2

8.81
6.35

0.19
1.57

1.2
21.3

4

1.2 104
1.1 102000800

11231500

4Ca2+
Mg2+K+

56NH4-N

700

5NO3-NP2O5600

3500

14100062500
230.6LowerLimit

1400300
2000.72 3 4 545 60
Southern Mongolia Fine sand(Habitat, 0cm)

100

6Potting compost(Japanese)

NH4-N, NO3-N, P2O5 (mg/kgdry)

Groundwater levelS1-2(NH), S1-3(H) : -350cm(Sep.)
S3-3(NH): Unmeasurable
S3-7(H): -150cm(June), -240cm(Sep.)

Distributions of water content in soil profiles in southern
Mongolia.

Case-3110100 1000 10000
Grain size diameter (Pm)name/unitSouthern Mongolia(Habitat, 0cm)
Fine sand200

Fig 3.

0.1

materials used
used ininexperiment.
experiment.
Table 2. pH, EC and CEC of habitat and materials

50250

D30D50
Uc
Uc'
188.21 261.65 2.62 0.99
6.09 13.45 10.20 0.97
7.09 15.44 9.75 0.97
2.85
5.12 5.56 0.98
117.08 148.46 2.00 0.99
124.55 176.72 3.11 1.15

Fig. 4. Grain size distributions of habitat and sandy soil.

Ca2+, Mg2+, K+ (mg/kgdry)0

Water content (Directly measured) (%)
5101520250cm
50cm
100cm
150cm
240cm
Fine sand

20Fig. 2. Conceptual scheme of cultivation in arid land.
00cm
50cm
100cm
150cm
240cm
Fine sand800Fig. 5. Chemical compounds of habitat and materials used inexperiment.

and propagation, various conditions of cultivation experimentwere conducted.
In order to quantify the relationships between soil
water/calcium environment and growth of licorice, thecultivation experiment was conducted using sandy soil
imitating arid environments in conformity. This experiment
was conducted at the Cultivation Institute of Herbal Plants inGenkai town, Saga prefecture, Japan. Two greenhouses wereused for the experiment, and the grounds of these houses were
homogeneous sand from surface to a depth of 250 cm.
Figure 4 shows the grain size distribution curve of fine sand(Silica sand No.7), which was selected as the experimental soil.
This Figure also indicates grain size distributions of Mongoliansoil at each depth from the surface to depth of 240 cm forcomparison. The uniformity coefficient and coefficient ofcurvature of fine sand were similar to Mongolian arid ground,especially at the surface and 240 cm depth. For these reasons,fine sand was selected as the experimental ground. Greening115

Table 3. Conditions of additional compost or lime.
No.
No.

Nutrition conditions
Nutrition conditions

2Calcium carbonate(Ca)Amount of additional ingredient (g/m )Magnesium (Mg)
Pottasium (K)Nitrogen (N)

1st year

1st year 2nd year 1st year 2nd year 1st year 2nd year 1st year 2nd year

2nd year

Phosphorus (P)11 O
rg an ic ccompost
o mp o s tOrganic

77.50.50

222.50
2.50

33.00
.00

99.00
.00

112.602.60

337.807.80

88.40.40

225.205.20

113.803.80

441.401.40

22 O
rg an ic ccompost1/2
o mp o s t 1/2
Organic

33.75.75

111.25
1.25

11.50.50

44.50
.50

66.30
.30

118.90
8.90

44.20
.20

112.60
2.60

66.90
.90

220.700.70

33 O
rg an ic ccompost1/8
o mp o s t 1/8
Organic

00.94
.94

22.81
.81

00.38
.38

11.13
.13

11.58
.58

44.73
.73

11.05
.05

33.15
.15

11.73
.73

55.18
.18

44 Organic compost + Magnesium lime

142.50427.50

18.00

54.00

12.60

37.80

8.40

25.20

13.80

41.40

55 M
ag n es iu m llimeime
Magnesium

1135.00
35.00

4405.00
05.00

115.005.00

445.005.00------

66 M
ag n es iu m llime1/2
ime1/ 2Magnesium

667.507.50

2202.50
02.50

77.50
.50

222.502.50------

77 O
rg an ic llimeime
Organic

1133.9533.95

4401.85
01.85

00.98
.98

22.93
.93

00.26
.26

00.78
.78

00.42
.42

11.26
.26

00.35
.35

11.05
.05

Volumetric water content (%)
24
68

1000

High
water amountGW:-240cm

GW:-200cm
Low water amount

Depth (cm)20

Average root length
High water amountLow water amount

40RootWaterlength(cm) amount(%)

60
HighWater amount
LowWater amount

8078271.7

3883.4100120Fig. 6. Distributions of volumetric water content of experimental
ground.
100GC content㽢root length (%䤸cm)

soil materials consisted of potting compost (J), which ismanufactured by Takii and Co., Ltd. Young licorice wasplanted in greening soil materials at a depth of 30 cm. Table
2 shows pH, EC and CEC of fine sand, potting compost (J) andthe natural habitat of licorice in Mongolia.
As shown in Table 2, potting compost (J) has 10 times
higher CEC than imitated arid sand, therefore potting compost(J) could provide sufficient nutrition for plants. And the CECof imitated arid sand was similar to that of the actual ground.
Furthermore, Figure 5 shows the amounts of calcium
carbonate (CaCO3), exchangeable cations (Mg2+, K+, Na+) andorganic components (NH4-N, NO3-N, P2O5).
Pottingcompost (J), which has significant organic components andnutrition, appeared to be suitable for propagating young
licorice as the plants grew about one month after planting.
Using these greening soil materials and fine sandy ground,
two types of water conditions were prepared in order to reveal
the relationships between growth of licorice and soil waterenvironment. These conditions are described in Section 3.1.
Moreover, in order to clarify the relationships between growthof licorice and nutrition, several kinds of fertilizers were addedin the ground as shown in Table 3. The types of fertilizers
included an organic manure, which is a mixture of compostand bokashi (extended slow acting fertilizer) as well as twotypes of calcium carbonate, which were organic calcium andmagnesium lime which mainly included CaCO3. These wereadded to mimic the soil saline environment in arid areas.
Under these soil water and saline conditions, licorice had beengrown for seven months and nineteen months. Root growth
can be measured as length, weight, and diameter. In thispaper, root length (RL) was selected as one of the indices ofgrowth because root lengths are more important considering
groundwater level in arid areas. In addition, for thepharmaceutical use of licorice root, glycyrrhizin (GC), which isan effective herbal ingredient in the root of licorice, wasselected as one of the important indices. Therefore, theproduct of GC content and length of root (GC*RL) was used
as a parameter of plant performance.



80

60

40

200Low water amountHigh water amount㻌3

3

2(2.71m /m ) (n=6)

㻌2(0.83m /m ) (n=21)

Fig. 7. Relationships between water amount and growth of licorice.

3. Results
3.1. Influences of soil water conditions on licorice growth
Figure 6 indicates distributions of volumetric watercontent in imitated grounds. Two types of water levels (Highand Low) were prepared. Water amount was defined byintegral calculus of volumetric water content and depth.
Average root length of the condition of “High” was about 78
cm whereas in the “Low” it was about 40 cm. In addition,
Figure 8 shows the relationships between water amount andGC*RL. As shown in Figure 7, it could be revealed that in
the case of the “High” water amount, the depth of root length
was high and GC*RL was higher than the case of the lowerwater amount. Therefore, it can be assumed that licoriceneeds supplemental water when in initial stages of growth anda supply of water in dryland areas will be needed.

116

1. Organic
Organic compost
compost1.
2. Organic
Organic compost
compost 1/2
1/2
2.
3. Organic
Organic compost
compost 1/8
1/8
3.
4.
Organic
compostMagnesium lime
lime
4. Organic compost ++ Magnesium
5. Magnesium
Magnesium limelime
5.
6. Magnesium
Magnesium lime
lime 1/2
1/2
6.
7. Organic
Organic lime
lime
7.

025
50
75 100100 125
125 150150
Content ofof additional
additional Ca
Ca (g/m(g/m22)
Content100
90GC×Length(RL)(%×cm)
GCcontent(GC)㽢 RootRootlength
Length(RL)(RL)(%*cm)(%㽢cm)
GCcontent(GC)×Root
GCcontent
content(GC)(GC)㽢Rootlength(RL)(%*cm)

GC× Root length
Length(RL)(RL)(%*cm)(%×cm)
GCcontent
content(GC)(GC)×Root))m70
mc㼪c*䞉%60(%)()
LL
R
R(( 50hthgtgnn
lee40
toLoto㼪Ro 30㼪R䞉)䞉
C)
G(Ct G20n(tentneoctn10
CcoGC
G080
7060
504030201000400 500
500 600600
100 200 300 400
Content of additional Ca (g/m22)

Fig. 8. Relationships between additional calcium and growth oflicorice (cultivated for seven months).

Fig. 9. Relationships between additional calcium and growth oflicorice (cultivated for nineteen months).

3.2. The relationships between calcium content in the sandand growth of licorice
Based on the relationships between additional CaCO3 andgrowth of licorice shown in Figure 8, it was found that GC*RL
tended to be higher when content of additional CaCO3 washigher, though other kinds or amount of additional nutrition,such as nitrogen and phosphorous, which was added at thesame time was different. Therefore it could be assumed thatgrowth of licorice will be higher if calcium content in the soil ishigher. Moreover, several cultural experiments of licorice
using various kinds of calcium compounds whose pH or EC
was different were conducted (Kameoka et al., 2013), andrevealed that licorice could grow better in an acidic
environment though licorice lives naturally in alkaline ground.
According to these results, growth of licorice was affected bycontent of calcium in the soil rather than content of manure andvalue of pH in the soil.

In addition, licorice could survive using greening soilmaterial because of the material’s high water and nutrient
holding capacity.
2) Licorice at the initial stage of growth requires more water
as indicated by the fact that growth of licorice was twotimes higher when water content was three times higher.
3) The higher additional calcium content in the soil resulted in
more licorice growth within the limits of 600 g/m2. Thistendency was same regardless of cultural year.
4) The relationship between geo-environmental factors andgrowth of licorice, can be described by the function:
GC u RL f ( w, Ca , D )(1)where GC is content of glycyrrhizin (%), RL is Root length (cm),
Ca is content of calcium in the soil, and D is weather factors suchas air temperature, relative humidity, amount of precipitation.

3.3. Influences of soil calcium environment on growth oflicorice over time
Figure 9 depicts the relationships between additional
calcium and growth of licorice. These results were measured
nearly two years after the cultivation experiment started, andadditional composts or limes were added as indicated in Table
2. The tendency of growth remained the same. And thetrend line was gentler in the second year when compared to thefirst year. From these results, it is implied that additional
calcium may not be necessary when licorice cultivation isconducted in arid environments when the distance between
individuals is around 30 cm.

4. Conclusions
This research was aimed to evaluate the relationships
between soil water and calcium environment in an experimentin Mongolia and Japan. The following results were revealed:
1) From the results of cultural experiments in the Mongolianarid, non-habitat area, the soil had about 3% water content.

Acknowledgement
The authors would like to acknowledge financial supportfor the project from Kyushu-University and Genkai town. In
addition, we are very grateful for staff of Cultivation Instituteof Herbal Medicine in Genkai town and Mongolian Academyof Science for their support of cultural experiments and in-situ
investigation.

References
Furukawa Z., Yasufuku N., Omine K., Kameoka R. (2013): AStudy about evaluation method of the relationships between
soil water/ calcium environment and growth of licorice
aimed at combating desertification. Proceedings of 10th JGS
Symposium on Environmental Geotechnics, 55-58.
Kameoka R., Yasufuku N., Omine K., Furukawa Z. (2013):
The fundamental research about geo-environment ofdryland which licorice grows wildly in southern Mongolia
and cultivation experiment of licorice which paid attention
calcium contents. Proceedings of 10th JGS Symposium onEnvironmental Geotechnics, 59-6.
Shoyama Y. (2002): Wisdom and nature of Asia. KUARO,
35-48.
UNEP (1992): Status of Desertification and Implementation of
the United Nations Plan of Action to Combat Desertification.