27-28 November, 2017
at Thuyloi University, Vietnam
Organized by IC-GU12UGSAS-GU & Thuyloi University – The 5th International Workshop 2017
–Recent Progress in Agriculture and Water Management in Asia–
Date: Nov 27th- 28th 2017
Venue: Room 5, K1 Building - Thuyloi University (TLU)
Address: 175 Tay Son Str, Dong Da District, Hanoi, Vietnam
Master of Workshop: Ms. Le Thi Thanh Hue (TLU) and Prof. K. Hiramatsu (Gifu U)

Contents and Program of the 5th International Workshop 2017
Start
time

Session

8:30

Registration

Speaker/Chair Person

Title

9:00

Chair: Assoc. Prof. Onishi, T.,
Welcoming and Introductory Session
Gifu U

9:00

Prof. Senge, M., Dean of
UGSAS, Gifu U

Declaration of Opening

Prof. Nguyen Quang Kim,
Rector of TLU

Welcome Address

9:10

Session 1

9:20

Prof. Hiramatsu, K., Adviser inInternationalization activities in UGSAScharge of International
GU
Affairs, UGSAS, Gifu U

9:30

Assoc. Prof. Nguyen CanhThai, Vice Rector of TLU[Keynote Speech] Disaster managementand dam safety issues

10:20

Chair: Assist. Prof. Noda, K.,
Gifu U

Scientific Presentation on Irrigation
Facilities

10:20

Assoc. Prof. Nishiyama, T.,
Gifu U

Analysis of the strength of rockfoundations for the safety of dams

Page

Tea Break

10:35

Session 2

10:50

11:20
11:35
12:00

Assoc. Prof. Nguyen Cao Don, Discharged Flow from the Effluences of a
TLU
Thermal Power Plant

5

Mr. Chihara, E., Sanyu
Consultant

9

A study for Water Stops Installed Outsideof Galleries on Deformable Ground

A Study on the Operation Procedure of
Assoc. Prof. Nguyen Thu Hien, South Nghe An Hydraulic System for
TLU
Irrigation under Water Shortage
Conditions
How the water distribution pattern to
Assoc. Prof. Onishi, T., Gifu U paddy plots will change by an adjustmentof weir height - trial simulation –
Q&A

11:05

Photo Session
and Lunch Break

1

13

17

Starttime

SessionSpeaker/Chair Person

Title

13:30

Chair: Assoc. Prof. Don, TLU

Scientific Presentations by Students andalumni of IC-GU12

13:30

Mr. Tran Duy Quan, Gifu U&
Thuyloi U, PhD student

Research on cause of KE 2/20 REC dam
failure in Vietnam from view point ofhydraulic fracturing

19

13:45

Mr. Muto, K., Gifu U, MS
student

Characteristics of denitrification in an
agricultural drainage channel

25

Session 3
14:00

Ms. Dinh Lan Phuong, PhD
candidate of TLU

14:15

Dr. Afandi, Lampung U

14:30

Prof. Dwi Priyo Ariyanto,
Sebelas Maret U

14:45

Q&A

15:10

Chair: Assoc. Prof. Hien, TLU

15:30

16:15

16:00

35
41

Session 4

Scientific Presentations on Water
Management and Agriculture[Keynote Speech] Recent water
Assoc. Prof. Iida, T., The
management technology of rice
University of Tokyo
cultivation in Japan and our future
research needs
Co-design of adaptation to Climate
Change with the current strategy in theAssis. Prof. Noda, K., Gifu U
water management sector in Thailand –A
concept for multi-criteria analysisEnergy use efficiency of integrated riceDr. Nguyen T. Hang Nga (TLU) duck farming in a selective area of Ha
Nam province, Northern Viet Nam
The effect of Deficit Irrigation on
Prof. Shakil Uddin Ahmed,
Root/Shoot ratio, Water Use Efficiency
Dhaka Uand Yield Efficiency of Soybean

16:45

Q&A

17:10

Prof. Nakano, K., Vice Dean of
Closing
UGSAS

18:00

MOC: Assoc. Prof. Nguyen
Canh Thai, TLU

Day2

29

Tea Break

15:30

16:00

Alternate Wet and Dry irrigation
technique – an adaptable solution toclimate change for rice cultivation in the
Red River Delta, Vietnam
Water Management along the Year -A
case Study in Pineapple Plantation underhumid tropical climate of IndonesiaSediment Trap using Small FarmReservoir in Rainfed

Page

BanquetExcursion

45

47

49

57

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

Analysis of the strength of rock foundations for the safety of dams
○Tatsuro NISHIYAMA(Faculty of Applied Biological Sciences, Gifu University)
SUMMARY
In the present paper, the direct shear of rock masses was analyzed with a set of plaster model tests and a finite element
analysis for the safety of dams. The plaster model tests simulated the direct shear tests which are actually carried out for
in-situ rock masses in order to obtain the shear strength of dam foundations. Failures progressively occurred throughout
the process of the tests. The cracking patterns depended upon the normal stress range; and therefore, the strengthappeared in different ways according to the normal stress range. In the cases with macroscopic discontinuities, thestrength of the discontinuities affected the shear strength much more than the strength of the material itself. Suchstrength was explained properly with the theoretical strength of the materials, including the weak planes. In the finite
element analysis, the appearance and propagation of cracks were accurately obtained. As the next step, further progressin the stress analysis of direct shear is desired.

Introduction

cause of failures in actual cases.

Engineers who are engaged in the work of agricultural

This paper reports the results of experiments which weredams in Japan have recently encountered two newcarried out to clarify the failure mechanisms and thephenomena: the first is the appearance of damage toresults of the numerical analysis simulating thedams after their long-time use, and the second is severe

experiments.

damage to dams occurring after well-known huge

Problems

earthquakes. Great efforts have of course been made to

Figure 1 shows diagrams of the in-situ tests used tocounteract these problems; however, there are manyobtain the strength of rock foundations. Firstly, a block isdifficulties which cannot be treated sufficiently with theshaped for loading, and an inclined force is imposed on it

existing knowledge and techniques. Moreover, suchincrementally under the desired constant normal force.

difficulties are not always new. What is necessary for

Then, the block is forced to separate from the rockengineers now is not only to break new grounds, but also

foundation. The resultant maximum tangential force per

to make up for the problems which have remained

unit area, namely, the shear stress, on the base of theunsolved for years. One of these problems is identifying

block which is treated as the anticipated shear plane, isthe mechanisms of the direct shear of the materials,

regarded as the shear strength of the rock mass underincluding rock masses.

consideration.

The shear strength of the rock foundations of large dams

A failure like that in the above-mentioned tests, where

was recognized after the famous Malpasset Dam Breakthe shear of a particular plane is forced, is called direct

in 1959. Since then, in-situ tests (International Society

shear. With such a failure, the shear strength is related tofor Rock Mechanics (1974)) have been carried out at

the normal force per unit area, namely, the normal stress,

many dam sites to measure the shear strength of rockand the relation is treated as a linear function which ismasses. Certainly, the resultant resistance has been

known as the famous Coulomb’s criterion.

measured and the results of such tests have been

On the other hand, it is also widely known that theavailable for use in the design of dams.

normal stress and the shear stress on a plane in an

However, the mechanisms of shear failure have not been

arbitrary direction are both represented on Mohr’s circle.

explained, particularly according to the fundamental

After a set of material tests, some circles at failure are

Mohr’s theory. To understand the strength that appears in

obtained; their envelope represents a failure criterion of

the shearing process, the process must be solved

the material. Since the failure occurs as shear undertheoretically. This is also important for interpreting thecompression, such an envelope should correspond to1

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017yxyNormal stress σ and shear stress τ are given as
σ = (FN + FI sin θ) / A, τ = FI cos θ / A

Plaster modelx

on the anticipated shear plane. The maximum value forτ and the corresponding value for σ are used todetermine the strength. Initial normal stress σn is given

Fig. 2 Brief description of the set-up of the model
tests. The plaster model is shown in gray. The blockpart to be sheared is set as being inclined.

asσn = F N / A .
After performing the test several times, all of theresults are arranged into Coulomb’s criterion.

Fig. 1
tests.

1

1

1

2

2

2

3

3

3

Schematic diagram of the in-situ rock shear

Coulomb’s criterion of the material, if both of them areappropriate for the material under consideration.
However, it is known that Mohr’s envelopes for rocks
and rock masses are curvilinear (Hoek (1983)).

σN = 0.625 MPa

σN = 1.25 MPa

σN = 7.5 MPa

(a)

(b)

(c)

In addition, Mohr’s envelopes show failure planes in a
Fig. 3 Crack sequences observed in three cases ofthe plaster model tests.

particular direction at any failure. Such failure planes
offer good interpretations in cases under simple pressure,
like in triaxial tests, which are often performed for

Figure 3 shows the crack sequences observed in threegeomaterials. However, such good interpretations cannot

test cases. All of the cases were divided among thesebe obtained in cases of direct shear where the shear of athree typical cases. The first type, shown in Fig. 3(a),particular plane is forced because the directions of thewas obtained under lower normal stress. Firstly, a tensile

simple compressional stress, namely, principal stress, arecrack initiated and propagated forming a curved path.

unknown. In-situ rock shear tests are conducted underThen, a few small cracks appeared at the center of theexactly such conditions.

block base, marking the peak of the shear stress, namely,

Plaster Model Tests

the shear strength, at the same time. Those small cracks

To simulate the in-situ rock shear tests, a set of plasterwere diagonal to the block base. The second type, shown

model tests was carried out. Each plaster model had ain Fig. 3(b), was obtained under middle normal stress.

block part, to be loaded, and was shaped into a flat form

The features of the cracking process and the appearance

in order to observe cracks throughout the loading process.

of strength are almost the same as those of the first type,The models were set to be inclined and adjusted to the

except that the tensile crack did not appear for this type.

loading apparatuses in each case for actual operations

The third type, shown in Fig. 3(c), was obtained under(Fig. 2).

higher normal stress. The deep zone seemed to be highly2Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

Shear stress τ (MPa)Material strength(a)Intact(a)(b)

Fig. 5 Finite elements to simulate cracks: (a) An
ordinary triangular element; (b) An enhanced
element including an interface Γ (Bolzon (2001)).
Normal stress σ (MPa)Shear stress τ (MPa)Material strength(b)Intact(a)(b)ψ

Normal stress σ (MPa)Fig. 4 Shear strength: (a) Results of the model
tests; (b) Results of the computation.
compressed and widely crushed. Even after being
severely crushed, the block seemed to be pressed and

(c)

(d)

rubbed strongly against the foundation part.
Fig. 6 Results of the finite element analysis: (a)Discretization for the intact model. The normal force
was imposed on the node enclosed with a circle. The
inclined force was imposed on the node marked witha circle and a triangle, as the incremental
displacement; (b) Results for the intact model, σN =Figure 4(a) shows the strength obtained in all the cases.
The black points are for the ordinary intact models. The
features of the distribution of those points are
represented

in

the

figurecorresponding

to

the

above-mentioned three types. Only the results of the0.625 MPa, whose results for the actual experiment are
shown in Fig. 3(b); (c) Cracks on the actual layered model,
ψ = 45°; (d) Results for the same case as (c).

second type belong to Mohr’s envelope which was
obtained by the other material tests as the material
strength. The strength for the third type seems toincluding the weak planes (Jaeger and Cook (1976)).

correspond to that of the crushed material.

Numerical Analysis

The second type was also reported in past research done

As mentioned above, the fundamental theory of theon concrete structures (Kaneko et al. (1993)), and seems

failure of rocks and rock masses is essentially related toto be similar to the common damage found on actual

the stress in the materials. However, it is exceedingly

structures or grounds. Tensile cracks, like those of the

difficult to obtain such stress values for actual materials.

first type, are occasionally observed at actual dam sites.

Therefore, another stress analysis is necessary to explain

The results of the third type seem to be similar to actual

thecrush zones.

experiments.

The other points in color in Fig. 4(a) show the results forIn this study, an analysis of the crack initiation andthe models which had layered discontinuities, like those

propagation by the finite element method is performed.

shown in Fig. 6(c). The strength of the discontinuitiesAt

affected the shear strength much more than the strength

satisfactorily; however, the numerical computation isof the material itself. Such strength can be properly

able to realize a good simulation of the crack initiation

explained by the theoretical strength of the materials,

and propagation in the actual experiments.

3

failurepresent,

mechanisms

theanalysisinthecannotabove-mentionedbecompletedProceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

To simulate the cracks, enhanced finite elements, each offollowing conclusions can be drawn.

which includes an interface (Bolzon (2001)), were

- Failures occurred progressively throughout the processadopted, as seen in Fig. 5. Initially, the incrementalof the tests, and it was found that the cracking patterns

computation was started with ordinary finite elements for

depended upon the normal stress range. The strength

every case, and the elements whose stress values reachedappeared in different ways according to the normal

the material strength were replaced with enhanced

stress range.

elements. The simple contact analysis was done on the- The strength of the discontinuities affected the shear

interfaces in the enhanced elements, and also on thestrength much more than the strength of the material

outer boundary and the initial discontinuities if given.

itself. Such strength was accurately explained by the

Figure 6(a) presents a discretized model of the intact

theoretical strength of the materials, including the weakplaster model.

planes.

Figure 6(b) shows one of the results of the finite element

Furthermore, a finite element analysis for the appearance

analysis for the plaster model. The crack distribution isof cracks and their propagation was developed for thesimilar to the corresponding actual results shown in Fig.

simulation of the plaster model tests. As a result, the4. Furthermore, Fig. 6(d) shows one of the results for theappearance of cracks and their propagation, as well as

layered model and corresponds to the actual results

the stress relaxation caused by them, were obtained

shown in Fig. 6(c). They are also similar to each other.

correctly. In the next step, further progress is needed for

Figure 4(b) shows the strength obtained through thea stress analysis of the direct shear.

finite element analysis. Compared with Fig. 4(a), theReferences

strength of the intact models was entirely computed as1) Bolzon G (2001) Formulation of a triangular finite
element with an embedded interface via isoparametricmapping. Computational Mechanics, 27: 463–473.
2) Hoek E (1983) Strength of jointed rock masses.
Géotechnique, 33(3): 185–223.
3) International Society for Rock Mechanics
Commission on Standardization of Laboratory and Field
Tests (1974) Suggested Methods for Determining Shear
Strength.
4) Jaeger JC and Cook NGW (1976) Fundamentals ofRock Mechanics. 2nd ed. London, Chapman and HallLtd.
5) Kaneko Y, Connor JJ, Triantfillou TC and Leung CK(1993) Fracture mechanics approach for failure ofconcrete shear key. I: Theory. J. Engng. Mech., ASCE,
119(4): 681–700.

the lower value; however, the shape of the row of points
is similar to that in Fig. 4(a). On the other hand, thestrength for the layered models seems to be similar tothat in Fig. 4(a). It is desirable that details on theprocedure for the crack appearance and crushed material
be improved. Thereafter, as the next step, the stressanalysis itself should be enhanced by an examination of
the obtained stress values.

Conclusions
From the results of plaster model tests, which simulate
the direct shear tests for in-situ rock masses, the4Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

DISCHARGED FLOW FROM THE EFFLUENCES OF A THERMAL POWER PLANT
Nguyen Cao DON (グエンカオドン) 1,*  and Nguyen Thi Minh Hang 2
1

Faculty of Water Resources Engineering, 2 Faculty of the Environment, Thuyloi University (WRU)
175 Tay Son, Dong Da, Hanoi, VIETNAM
Email: ncaodonwru@gmail.com

in which S – is the concentration of salinity or temperature;
Di - the dispersion coefficient in the i-direction, which isdependent on grid size and the computing time step, and SS- the source/sink term. The dispersion of salinity and temperature is assumed to be proportional to the effective eddy
viscosity with the factor of proportionality being 1 /  T , thedispersion factor;  T is the Prandtl/Schmidt number. Values of  T greater than one imply that diffusive transport is
weaker for salt/temperature than for momentum.
In this study, MIKE 3 model (DHI, 2003), a modeling
tool, was newly set up for the study area. The model consists of two main modules: a hydrodynamic module and an
advection-dispersion module. The bathymetry data wereconstructed based on a local map with some modification
to the shoreline because of land reclamation activities taking place in the area.

ABSTRACT
Prediction of the transport of effluent discharged fromthe outfalls of thermal power plants to coastal waters is an
important task in coastal environment and related areas, notonly to operation and design of the plant but also to living
systems due to changes in water temperature. In this study,
the hydrodynamic characteristics of water flow and heattransport in a tidal flat of Vietnam were studied using a
numerical hydrodynamic heat transport model. The model
was calibrated with observed data and it well reproduced
water level, salinity and seawater temperature. We foundthat the tidal currents and winds play an important role inthe dynamics of water temperature in the tidal flat area.
INTRODUCTION
This study was carried out for effluents of the Cam Pha
thermal (coal-fired) power station, which is located on the
shore of Bai Tu Long Bay, northern Vietnam (Fig. 1). The
power station consists of three plants, two existing ones
(CP1, CP2 with outfalls O1, O2 respectively) and one (CP3,with influent I3 and outfall O3) to be constructed. The
plants will be using seawater from the bay for cooling purposes. Based on thermal specifications for these plants,
there is a need to conduct a research on how thermal effluents affect the ambient water on the bay and on the influentof CP3 in order to fix its location. There is a number of operating scenarios; however, we here considered only thecase when all plants are working together.
METHOD AND MODEL SETTING
The transport equation for salinity or temperature is of
the form:
1 (  S )

S

( Di
)  SS
 t
x j
x j

Fig. 1 Map showing location of the study area
A 3-D finite-difference grid was developed to adequately
discretize the model domain. One of the objectives for griddevelopment is to sufficiently discretize the model domain
while minimizing the total number of model cells (Don et(1)5Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 201731.0

al., 2007). The area of interest is approximately 7.0 x 6.0
km2 and is covered with a 3-D grid. The sizes of each cellare x = 50 m, y = 50 m. The vertical direction, z, is divided into 5 layers with z = 1 m interval. The 2-D gridcontains 17324 cells: nx = 142, ny = 122, where ni denotes
the number of cells in the i direction.
The information on ui at each time step is provided by
the hydrodynamic module and is assumed constant during
each time integration of the advection dispersion equation.
The advection-dispersion equation is solved at each time
step following the time integration of the hydrodynamic
equations. The turbulence is modeled in terms of an eddy
viscosity and a bed shear stress. The eddy viscosity can dynamically be specified by means of the mixed k/Smagorinsky formulation with a standard k- model in thevertical and a Smagorinsky formulation in the horizontal(Don et al., 2007; MIKE3, 2001).

Computed

Salinity (psu)

30.0

27.0
07-05-08
12:00

08-05-08
12:00

Measured1.0u  air
 T

C W2

z
 w

0.0
-1.0

09-05-08
12:00

(2)

where air is the density of air, W - the wind speed at 10 m
above the sea surface, CW - the wind drag (friction) coefficient = 0.0026 for moderate and strong winds,  is the density of water.
The effects of northeastern (NE) wind and southwestern(SW) winds to seawater temperature at I3 are plotted in Fig.

-2.0
09-05-08
0:00

10-05-08
0:00

Effect of winds
In the bay, winds are significant, which cause large variations in the water properties by advecting the waters onand offshore, and strongly influence the direction of flow
circulation. Therefore winds contribute great effects to the
distribution of seawater temperature. The optimal conditions for input of this coastal water are NE and SW winds,
which are driving forces for current waters to run up andalong the shoreline.
The wind friction originates from the vertical shear term
assuming a balance between the wind shear and the water
shear at the surface:

2.0

08-05-08
12:00

09-05-08
12:00

ture. Extremely low surface salinity occurred during web
tides. Calibration of the model for water temperature however was not done because of there were no observed data
as long as the plant is in operating conditions. From theabove results, we newly found that the thermal plants willcontribute small impacts to the seawater levels and salinity
concentrations in the local bay.

Computed

08-05-08
0:00

09-05-08
0:00

Fig. 3 Comparison of computed salinity (lines) and observed one (dots)

4.0

Water level (m)08-05-08
0:00

Time (date, h)Calibration of the model focusing on choosing parameters was achieved through trial and error for water level, salinity and water temperature. Figure 2 plots the computed
sea water levels (lines) against the observed ones (dots).
The simulated tidal levels have a good agreement with theobserved ones. The errors (mean absolute error, relative
mean square error, mean error) are approximately 1% of
the water depth at this location, indicating that a good estimation has been obtained.
Figure 3 shows a comparison of computed salinity andthe observed one. Overall, the computed salinity follows
well the observed data. At low tides, salinity levels wereover estimated due to the effects of air and water tempera-

07-05-08
12:00

29.0

28.0

RESULTS AND DISCUSSION

3.0

Measured

10-05-08
0:00

Time (date, h)Fig. 2 Variation of computed seawater levels (lines) vs.
the observed ones (dots)

6

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

4. When the southwestern wind is dominant, the effluentsof O2+O1 will also make water temperature at the influent
I3 (Fig. 4a, b) to increase by 15%. The “Thermal Flumeand Mixing Zone” can be determined based on the size andspatial distribution of the thermal plume resulting from theoutfall discharges. The size and spatial distribution of themixing zone tend to vary considerably from time to time.
When the northeastern wind is dominant, the effluentsof O2+O1 will induce more change in water temperature ata) SW wind, flood tides

the influent I3 (Fig. 4c, d). The cooling water flume from
CP2+CP1 will tend to move to the southwestern part along
the shore. This will induce water temperature at I3 to increase up to 35% , especially at low tides (Don, 2008).
CONCLUSIONSIn this study, the effects of thermal effluents in the ambient water on the bay and on the influent I3 were addressed using a numerical model that simulates the hydrob) SW wind, web tides

dynamics of water flow and the dispersion-advection ofdensity currents. We found that winds play an importantrole in spatial distribution of the water cooling flumes. SW
winds will induce a higher water temperature in comparing
to NE winds. The location of the effluent I3 (300m fromO3) should be chosen so as to be less thermal influence
from the effluent sources, while not being separated fromthe plant. However, it is recommended that such a locationof I3 should be selected based on a more detail study in order to minimize the construction cost while also increasingc) NE wind, flood tides

the heat dispersion efficiency.
REFERENCES
Don, N. Cao (2008). Heat transport from the outfall of Cam
Pha thermal power plant. Unpublished report.
Don, N. Cao, Araki, H., Yamanishi, H., K. Ohgushi, Hang,
N. T. Minh, and Tokunaga T. (2007). Sedimenttransport and short-term sedimentation processes in the
tidal flats of the Ariake Sea, west coast of Kyushu, Japan. Journal of Coastal Research, SI 50, pp. 837-841.
DHI (2003). MIKE 3: Scientific Documentation. Estuarine
and Coastal Hydraulics and Oceanography Hydrodynamic Module.

d) NE wind, web tides
Fig. 4 Distribution of temperature in seawater in response to wind directions

7

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 20178

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

A study for Water Stops Installed Outside of Galleries on Deformable Ground
CHIHARA Eiji *1, NISHIYAMA Tatsuro,*2ISHIBASHI Shinji*1*1Sanyu-Consultants Inc, 35-16 Daikancho, Higashi-ku Nagoya-City Japan*2Fuculty of Applied Biological Science Gihu University Yanagito 1-1 Gihu City Japan
Abstract
In Japan, it is defined to construct a concrete gallery when construct a fill dam with a height of 30 meters or
more. However, in softer foundation ground, deformation of the foundation may occur. At the joints of the galleries, deformation of the foundation ground concentrates on it and the risk of hydraulic destruction by Infiltrationwater around the joint will increases. Here, I will introduce a water stop made by new ideas, installed on the outer circumference of the gallery, developed to prevent Infiltration water.

40

Ⅰ Introduction
Figure 3 shows the deformation of the foundation
The foundation ground of the dam site is the Mesozoground due to the analysis results. As a result, a subsidic sedimentary rock. The height of dam is 62.5 m. Andence as much as 30 cm was predicted on the left banksectional view of the foundation ground of the dam andside.
5 the rock classification of the ground are shown in Figure45
1. This rock classification was applied to this dam byarranging the standard rock classification used in Japan.
On the left bank side of the riverbed part of this dam site,
there is a large deformability part fractured by the fault.
10 The maximum width was 90 meters.
50

Fig 3 Result of deformation analysis
From this result, the establishment policy of the gallery15
was decided as follows. ① It was judged that the
55 amount of deformation was large on the left bank riverbed. As a result, it was judged that it was difficult to
Fig-1 Rock classification longitudinal section
install gallery on the dam axis center line. Therefore, as
The deformation coefficient of the foundation groundshown in Fig. 4, 5 the audit aisle arrangement of the riv20 corresponding to this rock classification is as shown inerbed was placed on the downstream side of the water
60 impermeable zone.
Table 1 Deformation coefficient of rock25

65

The deformation of foundation ground due to embankment weight was analyzed by finite element method.１） The analysis model is shown in Fig.2．The analy30 sis method adds embankment weights divided into nine70
stages.２）

Fig. 4 riverbed department gallery layout map

35
75

Fig. 5 Standard sectional of dam bodyFig 2 Deformation analysis model9

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

① water stop; double water stop structure insideand outside. Strong against high pressure water presdeformation of foundation groundsure.
② Joint grouting: After completion of the embankGallery have been established since the 1980s forsafety management and future repair. However, if thement construction works, mortar grouting is performed
5 deformation of the foundation ground is large, the 55
between double water stop preventing the water stop
ground deformation concentrates on the joint of the galdeformation due to water pressure.
lery. As shown in Fig. 6, the deformation shape of the
However, when the deformation becomes large, in the
joint is openings, gaps, and its composite shape.
portion indicated by the arrow shown in Fig. 9, a gap isgenerated outside the outer water stop, and it is impossi60 ble to deal with it from the inside of gallery. Then it will10
result in extremely dangerous situation in water shielding materials against upstream to downstream infiltration.

Ⅱ Problem of gallery joint caused by

Gap
15

opening50

gap and opening65

fig－6 Joint deformation overview

In this dam, FEM analysis including joint elements
was performed to estimate the gallery joint deformation.
As a result of the analysis, it became clear that the gallery deforms greatly toward the deformable ground. The
20 analysis result is shown in Fig-7. At the lower left abut,70
it was predicted that a maximum opening of 10 mmwould occur outside the gallery joint. Also, opening ofseveral mm was predicted for several joints.

Fig. 9 Gap formed during joint deformation

開き 10mm

25

Opening 10mm

75

Opening 10mm30

80Opening5mm

Fig. 7 Diagram of gallery joint deformation analysis
Ⅲ Gallery joints structures

85

Figure-7 shows a typical gallery joint struc35 ture.3)Various ideas are made at the gallery joint for the
purpose of preventing water leakage towards inside of
the gallery and dealing with local deformation etc.
90

40
95

100

45

Fig. 8 Diagram of gallery joint detail105

10

Fig.10 Opening formed between joints deformationon the top of the gallery joint
In the gallery bottom part, after the embankment construction, the main curtain grout and the water impermeable grout of the auxiliary curtain grout are constructed. However, if the joint dislocation or opening
due to the base deformation occurred after the embankment construction work, voids occurred at the top edge
and the foundation ground contact surface as shown in
Fig-10. As a result, there is a greater risk of progressive
destruction due to soil particle flow through the void
made by opening deformation. In this way, the water-stop of the fill dam gallery constructed on great deformable foundation ground, is insufficient to deal withinundation only to the inside.
1. Development of water stop installed
Outside of the gallery.
Against the above problem, we have developed waterstop structure by new ideas as followings.
① It is necessary to have a new idea of a water stops
that wraps the released space caused by displacement
and opening .
②In addition, a buffering backup rubber (B = 500 t =25 mm) for backing up the plastic deformation of themain water stops, was arranged outside of water stop.

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

Ⅳ Performance check test
55

10

Fig. 11 Explanation of outside water stop structure

20

25

Pressure test

Performance confirmation against water pressure after
completion of dam construction was carried out with theequipment shown in Fig.14。In the test, firstly, twopieces of the concrete device has been set in the state of
60 a gap 45 mm, and being set in the state of opening 15
mm. Next, an assumed water pressure of 6 kg / cm 2
was applied from the inside, and it was confirmed that
there was no decrease in internal pressure during the test
period.

515

1.

③ As shown in Fig. 12, construction was carried out
with primary concrete preceded by side walls and bottom so as to absorb irregularities of the rock surface.
The backup rubber and the outer water stop were set
there, and the main body concrete was constructed.

65

70

75

Fig. 12 Explanation of outside water stop detail
Since the outer water stop and the backup rubber are of
two kinds of rubber structures, the connection surface
30 was bonded with asphalt urethane rubber that is softerand slippery than these twe materials. These perfor- 80
mances are as shown in Table 2.4)
Table 2 Outer Water Stop Material PerformanceFig.14 Outline of pressure test
2. Construction confirmation test

The construction site of this joint type is constructedat the inclined slope part. On the other hand, the waterstop has many projections, and when vibrator work performed excessively the air separated from the concrete is
likely to accumulate. We have already confirmed this in
the indoor casting test. Then we conducted onsite tests
so that construction could be carried out safely. As forthe test the same scale of the gallery, two pieces of a 1 m
35
85 section concrete block including a joint was constructed.
In the field test, concrete was casted from the lower part.
And in the construction of the top part, stopping the vibrator work, the water stop was turned up toward thecenter part and the separated air was eliminated. AfterAs a result, the gallery joint structure shown in Fig. 13 90 that we added additional concrete, and finally we confirmed that we can push the water stop into the concrete
40 was adopted for the five joints at left side bank withby manual strike. Photo 1 shows that, after the test, thelarge displacement.
concrete block was cut with a concrete cutter, and it was
confirmed that the protrusion of the water stop was
95 surely being put into the concrete without air.
45

100

Air is likely tostay in this place50

Fig.13 gallery Joint section with new type water stop 105

11

Photo 1 Casting test Specimen after cuttingProceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

abnormality was found in the pore pressuregauge installed at the upstream and downstream of the
top of the audit corridor. From these observation results,
Measurement of gallery joint behavior, and observa25
it was judged that the water stops installed outside oftion against infiltration water along gallery joint were
gallery is functioning normally.
5 planned as follows. The opening and the gap of the joint
About 10 years have passed since then, no abnormalityof the gallery were monitored from the inside of gallery
is recognized. From this result, it is judged that theby many joint meter. On the top of gallery, pore pressure
newly developed water stop contributes to the hydraulicgauge was placed at upstream and downstream to ob30 safety of gallery joint of the dam constructed on the deserve infiltration water along the gallery joint.
formable ground.
10
Ⅵ Monitoring result

Ⅴ Construction works and behavior monitoring

At the joints, where the deformation prediction
has been done, predicted opening, and gap were
occurred. The maximum opening was 7 mm in
the width confirmed from inside of gallery. From 35
15 this, it is assumed that at the outer circumference, the opening of the gallery is assumed to be
10 mm. And it was judged to be the same as theinitial prediction. Water storage was started af- 40
ter the dam construction was completed, but in
20 the internal observation, no leakage trace, nor
free lime the joint was confirmed. In addition, no

12

Reference
1)
2)
3)
4)

Japanese Ministry of agriculture forestry fisheries, Design standards of Fill Dam PⅡ-149 ,Same as above PⅡ-150 イ FEM analysis including gallery
by joint elements.
Same as above PⅡ-150(4) Joint instruments and stop
water treatment
ASTM D412 Standard Test Methods for Vulcanized Rubber and
Thermoplastic Elastomers—Tension

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

A Study on the Operation Procedure of South Nghe An Hydraulic System for Irrigation
under Water Shortage Conditions○Nguyen Thu HIEN，Tran Dung TIEN
(Faculty of Water Resources Engineering, Thuyloi University）
SUMMARY
The South Nghe An hydraulic system has been upgraded with a new Nam Dan sluice to replace the old one to meet theirrigation requirement for 22,500 ha with the probability of 85%. The water is taken from the Lam River through Nam
Dan sluice. However, in recent years, due to the effects of climate change and human activities, the water levels in Lam
River tends to decrease considerably. This greatly affects the ability of taking irrigation water for agriculture.
In this paper,

MIKE 11 model was applied to compute the abilities of taking water to the system and the hydraulicregime in the system with 12 water shortage scenarios (different flow regimes with minimum water levels of the Lam
River at the upstream of the sluice below design water level). The computed results show that for some cases, both new
Nam Dan sluice and the old one should be operated together in order to increase water taking ability to the system.
Different operation options were computed corresponding to the scenarios to determine the appropriate operatingprocedures to increase the amount of water taken through the sluices to improve the irrigation water supply under water
shortage conditions in the study area.

Introduction

2014 the minimum water level decreased significantly,
from + 50cm down to -20cm. This trend considerablySouth Nghe An Hydraulic System has one main sluice,
the Nam Dan Sluice (old), built in 1936-1939 to takewater from the Lam River for water supply andnavigation in districts Nam Dan, Hung Nguyen, Nghi
Loc, Vinh and Cua Lo town. The sluice has beenworking for quite long time (more than 70 years).
Moreover, recently the cultivated area increases (from18,000 ha to 22,500 ha) and the water requirement
expanded for other sectors such as aquaculture andindustry... So that the capacity of the old sluice could not

Fig.1 Average water level of the years from1995-2014be satisfied the water requirement of the region.
Therefore, in 2008, a new Nam Dan sluice project wasapproved to replace the old one.
The new Nam Dan sluice was designed to supply water
for the South Nghe An area. The designed water level of+ 0.833m was calculated from water level data series(1960-2000) to ensure to supply water with frequency of
85%. However, currently hydrological data at Nam Dan

Fig.1**************************************

station from 1995 to 2014 show that the water level of
Lam River tends to decrease significantly. Fig. 1 shows
the average water level for the years from 1995 to 2014.
Fig. 2 shows the monthly minimum water levels in theFig. 2 Monthly minimum water level of the years
from 1995-2014 in dry season

dry season. The observed data show that from 2008 to

13

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

affects the water supply to the South Nghe An system.

[meter]Standard - Hydraulic scheme of South Nghe An system.res11

9200.0KENH NHA LE

9000.0KENH NHA LE
HTX NL 7

8800.0

Therefore, under the water shortage conditions in order8600.0SONG CAMCAM
HTX NL SONG2HTX NL 3
SONG CAM

8400.08200.0to increase the capacity of taking water from the Lam

8000.0SONG CAM

7800.07600.0KENH KHE CAI
7400.0River to the system, the old Nam Dan sluice is proposed

KHE CAIHTX NLKENH
6
HTX NL 5

7200.06800.0HTX NL 4
TB 186600.0to be operated together with the new one in case the new

HTX NL 1
TB THANH HASONG CAM

KENH KHE CAITB CHO QUANKENHKHE CAISONG CAM
KENH KHE
CAIKENH
KHE CAI

7000.0KENH GAI

6400.06200.0

TB CHO CAU
KENH THO SON
THOSONSONKENHKENH
THO SON
TB THO

6000.0one cannot take enough water to the system.

KENH GAI

5800.05600.0

TB CAU BAN
5400.0KENH GAI

5200.0HTX ND 3
TB BAU NON
KENH THAP
TB 2
KENH THAP
KENH THAP

5000.0In this paper, several scenarios of water shortages (when4800.04600.0KENHDIENTHAPTB VANTB 1
KENH THAPNHANH
NDANNDANCU MOINHANH

TB 16B
KENH GAIHTX ND 4
TB 15
KENHKENH
THAP THAPNHANH
NDAN MOITB 16AKENH GAIAU THUYEN
KENH THAPSONG LAM TRA
KENH GAITB 4AC TB 5
KENH THAPHTX HN 4
TB HUNG DAOKENH GAITB 14
HTX ND 1
KENH THAP
KENH GAITB 6
HTX ND 5
KENH THAP
KENH THAP
KENH THAP
KENH HOANG CANSONG LAM TRA
KENH THAP
KENH HOANG
SONG
CUA TIEN
7CAN
HTX HN3SONG
LAMHOANGTRATB CANKENH
HTX HN 1
HTX ND 2
TB 8HOANG CAN
TB 9
KENH
KENH
HOANG
CAN
TB 10
KENH
HOANG
CAN
KENH
HOANG
CAN
SONG CUA TIEN
KENH HOANG
CAN
TB 11
KENH HOANG CAN
KENH LE XUAN DAOTB 12
KENH HOANG CAN
KENH
HOANG
HOANG
CANCANHTX HN2 KENHTB 13
KENH
HUNG NGHIAKENH LE XUANDAOTBMYNGHIA
GIANG
KENH
KENH
LEHUNG
XUAN
DAO

4400.04200.0

the upstream water level is smaller than the designed

4000.03800.03600.03400.0water level) with different operation options in the dry

3200.03000.02800.0season (Winter-Spring crop) were simulated. From that,

TB 17
KENH GAIKENH THAPTB
3 THAP
KENH
KENH THAP
TB 4B

2600.02400.02200.02000.0appropriate operations are recommended to increase the

TB TIEN THANG
KENH HANH PHUCTB HUNG CHAU

1800.0KENH HANH PHUC

1600.01400.0capacity of taking water to the irrigation system, in order

0.0

500.0

1000.01500.02000.02500.03000.03500.04000.04500.05000.05500.06000.06500.07000.07500.08000.08500.09000.09500.0[meter]to reduce water shortage situation in the region.

Fig.3 Hydraulic scheme of South Nghe An system

MethodIn dry season, Nghi Quang, Ben Thuy drainage sluices

In order to solve this problem, Mike11 model (DHI,

are closed (South Nghe An Irrigation Drainage Company,2007) was applied to calculate the hydraulic regime of2008). Therefore, for this study the downstream

Nam Nghe An irrigation system. The MIKE 11 model

boundaries are closed boundaries. Other boundaries aredeveloped by DHI Water & Environment is ainternal boundaries at pumping stations in the system.

one-dimensional hydrodynamics, water quality andsediment transport model in river systems, canals with

Model calibration and verification
The model was calibrated by adjusting roughness

structures (dams, gates, pumps ...) reservoir and canalcoefficients using observed data at some locations on theans structure operations... This model is a very good toolsystem from April 14, 2015 to April 21, 2015. Figure 4

to help decision makers for design, management andshows that the measured and computed water levels at

operation of hydraulic systems.

the upstream of the 4A pumping station are quite closed

Hydraulic scheme of South Nghe An system

to each other. The difference between the computed and

The South Nghe An irrigation system has the following

measured water levels ranges from 0 to 7cm. The

head works: old Nam Dan and new Nam Dan sluices at

Nash-Sutcliffe coefficient is 96%.

the upstream (taking water from the Lam River) and

The calibrated parameter set is verified for the period 6th

Nghi Quang, Ben Thuy drainage sluices at downstream

June 2015 to 16th June 2015. Fig. 5 shows the observedof Cam River and Vinh River. The old Nam Dan sluice[meter]has 4 gates with the width of b = 2.0m each and a

1.00

navigation lock with the width of B = 5.0m, the inverts

0.90

Water Level
Computed WL at P.S 4ATime Series Water Level

External TS 1
Observed WL at P.S 4A

0.80

of the gates and lock is -1,30m. The new Nam Dan sluice

0.70

is designed with 3 gates, with the width of b = 5m each

0.60

and a navigation lock with the width of B = 7.0m, the0.50

inverts of the gates and lock is -1,40m. The system

0.40
0.30

consists of 4 main canals (Thap, Gai, Cam and Khe Cai)

0.20

and grade 1 canals with the length of 130 km. Inside the14-4-201516-4-2015

18-4-2015

20-4-201522-4-2015

stations. Water is pumped from the main canals andFig.4 Computed and observed water levels at the4A pumping station (model calibration)

grade 1 canals. The geometry data and the operation dataand computed water level at the 4A pumping station.

of pumping stations of the system are provided by the

From the figure it can be seen that the computed water

South Nghe An Irrigation and Drainage Company. Fig. 3

levels are closed to the observed ones with The

illustrates the hydraulic scheme of South Nghe An Nam

Nash-Sutcliffe coefficient of 0.78.

system, irrigation procedure is operated by pumpingin Mike 11.
Upstream boundary is the water level Z (t) of Lam River
at the upstream of the old and new Nam Dan sluice gates.
14

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

[meter]According to the local cultivation, there are 3 main crops

Water Level
Computed WL at P.S 4ATime Series Water Level

0.40

in the area (winter-spring crop, summer-autumn crop andExternal TS 1
Observed WL at P.S 4A

0.30

winter crop). Of which, winter-spring crop has most

0.20
0.10

difficulties in terms of water source because it is in the

0.00

dry season. Therefore, in this study, the simulation-0.10

duration is the dry season of the winter-spring crop

-0.20

(December-May).

-0.30

Result and Discussions-0.40

In the South Nghe An system, water is taken-0.50
6-6-2015

8-6-2015

10-6-2015

12-6-2015

14-6-201516-6-2015

gravitationally from the Lam River through the Nam Dan

Fig.5 Computed and observed water levels at the4A pumping station (model verification)sluice(s). Lam River's water level is affected by tides,

Scenarios and operation options
Operation procedure is considered under different

fluctuation in water level from 45 cm to 160 cm,

conditions of water shortage. 12 scenarios weresignificantly affects to the ability of taking water throughcomputed corresponding to the stage hydrographs of thethe Nam Dan sluices to the system.

Lam River at the location of the new Nam Dan sluice

Figure 6 shows the simulated stage hydrograph at somewith the lowest water levels ≤ + 0.83m

locations in the system corresponding to the scenario 1

especially in the dry season. The data show that the levelparticularly, in dry season, the influence of the tide(design waterlevel ) (see Table 1).

and the operation option 1. The figure shows that in

For each scenario, there are the following operation

winter-spring crop duration, the water levels from in

options:

January (3rd - 23rd January) in the system are very low-

because this is highest water demand for land preparation

Option 1 (O1): only the new Nam Dan sluice gates areand sowing. Therefore, this duration is most difficult time

Table 1 Water shortage scenarios (water level at
upstream of the new Nam Dan sluice)

to ensure water requirement and is chosen to discuss for
operation options in this paper.

Scenario
U/S WL(m)
Scenario

S1

S2

S3

S4

S5

S6

0.83

0.73

0.63

0.53

0.43

0.33

S7

S8

S9

S10

S11

S12

[meter]
1.10

Water Level
KENH THAP 20000.00
KENH HOANG CAN 10000.00
KENH GAI 15000.00
SONG CAM 20000.00
SONG LAM TRA 10000.00
KENH KHE CAI 15000.00

Time Series Water Level

1.00
0.90
0.80

U/S WL
(m)

0.23

0.13

0.03

-0.07

-0.17

0.70

-0.27

0.60
0.50

opened (completely or partly open);
-

0.40
0.30

Option 2 (O2): the new Nam Dan sluice gates and

0.20

navigation lock are opened (applied when option 1 is3-1-2015

not satisfied );-12-2-2015

4-3-2015

24-3-2015

13-4-2015

3-5-2015

23-5-2015

Fig.6 Stage hydrograph at some locations in thesystem (S1 - O1)

Option 3 (O3): the new Nam Dan sluice gates andnavigation lock are opened and combined with the old

Table 2 shows the total water requirement of the system

Nam Dan sluice gates (applied when option 2 is notand the total water volume can be taken through the Namsatisfied );-23-1-2015

Dan sluices under different scenarios and options. Total

Option 4 (O4): Same as option 3 with a combinationwater demand for the period from 3/1 to 23/1 is 43.977 mil.

of alternating irrigation inside the system (appliedm3(Water resources engineering institute , 2017). The

when option 3 is not satisfied).

results show that though the discharge requirement of the

It is noted that Nam Dan sluice gate(s) are operated tosystem in this duration is not properly satisfied but for

take water to the system and Nam Dan gates are closed

Scenarios S1 to S5, the new Nam Dan sluice can get

when water levels of the Lam River was lower than theenough the total volume to the system. For scenarios 6 andwater level of the Thap Canal (downstream of the gates).

7, it needs to open also the navigation lock to increase theSimulation time:

capacity of taking water.

15

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

show that, in order to improve the ability of taking water

Table 2 The total volume of water taking throughNam Dan sluices with different scenarios andoptions in January (mil. m3)
S1 - S5
S6
S7
S8

to the system in water shortage conditions in many cases it
is necessary to operate both Nam Dan sluices combinedwith alternating irrigation method.

O1

43.97743.29941.60641.132O2

43.97743.97743.97741.194conditions (for example for scenarios S9 - S12), besides

O3

43.97743.97743.97743.977

applying the proposed operation procedure, some otherO4

43.97743.97743.97743.977

solutions should be considered such as applying modern

S9

S10

S11

S12

irrigation technology to save water, regularly maintaining

O1

39.48237.59135.51933.085the hydraulic system (canals, structures, pumping

O2

40.71839.87838.61834.518stations…), applying new crops with high drought

O3

43.06341.21639.22934.894

tolerance, changing crop pattern.

O443.95842.48439.97835.408

Acknowledgement

It is also recommended that in very serious water shortage

All the data related to structures, canals, observed data[m^3/s][meter]Time Series

1.8
1.6

45.0

1.4
1.2

40.0

1.0
35.0

0.8
0.6

30.0

Discharge
Q comp. at ND sluice
Q comp. at new ND sluice
Q comp. at Thanh Ha P.S
Q comp. at N.L of new ND sluice

and gates and pumping station operation data of South
Nghe An hydraulic system were provided by the South

External TS 1
Q req. of South NA system
Q req. at Thanh Ha P.S

Nghe An Irrigation Drainage Company. The authors

Water Level
NHANH NDAN MOI 0.00
WL at upst. of Thanh Ha P.S

gratefully acknowledge.

0.4
0.2

25.0

0.0
20.0

-0.2

Reference

-0.4
15.0

-0.6
-0.8

10.0

1) DHI (2007). MIKE11 software - A modeling system
for rivers and channels
2) South Nghe An Irrigation Drainage Company (2008).
Decision on supplementary operation procedures for the
headwork sluices Nam Dan, Ben Thuy, Nghi Quang.
3) Vietnam standards (TCVN 8412:2010). Hydraulicstructures – Guideline for setting operation procedure.
4) Water Resource Engineering Institute (2017), Water
requirement computation for Nam Nghe An region.

-1.0
-1.2

5.0

-1.4
0.0

-1.6
3-1-2015

8-1-2015

13-1-2015

18-1-201523-1-2015

Fig.7 Computed stage and discharge hydrographand discharge requirment of the system andThanh Ha pumping station (S8 – O3)
For Scenario 8, when the water level in Lam River is very
low, if only the new Nam Dan sluice gates and lock areoperated, the total water volume cannot take enough water
for this duration. Therefore, it is necessary to combine theold one to increase the amount of water taken into thesystem (operation options O3). The results show that forthis case when two sluices operated together the total
water volume taken to the system satisfied the waterrequirement for this duration. Fig. 7 illustrates thedischarges flow to the system when both the sluices gatesand locks are operated.
From Table 2, it also can be seen that for scenarios S9 to
S12, even both sluices and navigation locks are operated,
the total water volume is not satisfied the waterrequirement. And for these conditions, alternating
irrigation method should be applied to reduce the effect ofwater shortage and regulate the requirement discharges.

Conclusion
In this paper, MIKE 11 model was applied to study
operation procedures for Nam Nghe An irrigation systemin water shortage conditions (water levels are lower thandesigned water level). 12 scenarios with different
operating options were considered. The computed results

16

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

How the water distribution pattern to paddy plots will change by an adjustment of weirheight - trial simulation ○Takeo ONISHI，Kimihito Nakamura(Faculty of Applied Biological Sciences, Gifu University, Faculty of Agriculture, Kyoto
University）
SUMMARY
We need to satisfy three different purpose, maintaining productivity, conserving water quality, and reducing
greenhouse emission simultaneously. Regulating water management is one of the promising way to achieve this goal.
Thus, the objective of our research is to evaluate how the different water management method will influence on the
productivity, water quality, and greenhouse emission. To achieve our goal we are conducting field measurements andnumerical simulations at Vietnam. As of the first trial of our numerical simulation, we assumed a simple imaginary case.
The results indicate that if we can properly set the weir height of the irrigation canal, homogeneous water distribution toeach plot might be possible. Further combined research of field measurements and simulations are required.

Introduction

Research framework is shown in Fig.1. We set three

Generally, the highest priority of paddy field is rice

different types of water management plots.

The first is

productivity and quality. To achieve that purpose,conventional management plot. The second is dry typeefficient water resource use is important. In other words,

management plot. And the third is wet-type managementsaving irrigation water is required. On the other hand,plot. Comparing these differently treated plots, we arepaddyvariousgoing to clarify which is the optimum management

environmental problems. Excessive drainage water,

method. One important characteristics of our research iswhich contains various materials, contaminate theconsidering a practical way to control water in paddy

downstream water bodies including rivers, lakes, andfield; i.e. by only implementing a small weir of which

oceans. And, a part of nitrogen fertilizer in soil goes toheight is different in canals, water regime of each plot

agriculture

sometimes

inducesgroundwater as nitrate, and induces groundwater

Paddy Block #1

Paddy Block #2

Paddy Block #3

contamination. Thus, water quality conservation of theConventional
management

Dry-Type
management

Wet-Type
management

downstream water bodies and groundwater is very
important for safe drinking water and ecosystem

To clarify the problemsof conventional water
management

conservation. Furthermore, a part of nitrogen in soil
emits to the atmosphere as N2O
and CH4 (methane) also

(nitrous oxide). CO2

Observation item

emit to the atmosphere fromsoil when organic matter is decomposed. These gases aregreenhouse gas and induce global warming. So, reducing

Optimalmanagement

To quantify the advantages
and disadvantages at each block

1. High rice productivity and quality
2. Irrigation water-saving
3. Water quality conservation
4. Reducing greenhouse gas emission

greenhouse gas emission from paddy field is also

Simple and easily understandable water management for farmers
and local managers.

required. Thus, we need to satisfy three different purpose,

Fig.1 Research framework

maintaining productivity, conserving water quality, andreducing

greenhouseemission

will be regulated.

simultaneously.

Regulating water management is one of the promising

Under the above-mentioned framework, we are now

way to achieve this goal. Thus, the objective of ourconducting field measurements such as water quantity

research is to evaluate how the different waterand quality, groundwater levels, volumetric soil water,

management method will influence on the productivity,

Eh of soil water, the amount of greenhouse gas (N2O,

water quality, and greenhouse emission.

CO2, and CH4) and rice productivity. Configuration ofMaterial and Method

the study site is shown in Fig.2.
Fig.1**************************************
17

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

Result and Discussion
Three different types of water level at the downstreamof canal were set as boundary conditions for eachsimulation. The first condition was 0.3m lower than thebottom elevation of inlets of plots (case1). The second
condition was 0.3m higher than the bottom elevation of
inlets of plots (case2). And the third condition was
periodical change of water levels between 0.3m lower
than the bottom elevation of inlets to 0.3m higher thanthe bottom elevation of inlets (case3).
The simulation results indicate in case of case1, water
Fig.2 Outline of the study site

distribution to plots are not homogeneous, since waterlevel of the canal at the downstream is lower than the

As a component of this research project, we attemptedbottom elevation of outlet. On the other hand, in case of

to simulate how the water distribution pattern to paddy

case2, irrigation water homogeneously spread out to theplots will change by an adjustment of weir height of anwhole area of plots, but also some water were flowing

irrigation canals. As of the first trial of our numericalback to the canal, since water level of the canal at thesimulation, we assumed a simple imaginary case shown

downstream is higher than the bottom elevation of outlet.

in Fig. 3. In the setting, one straight canal of which slope

In case of case3, the result indicate that if we can change

is 1/0000 is lined along two plots of which sizes are

the weir height according to the water levels of plots, we

100m×30m. Through the three small inlets (ditches dug

can properly manage the amount of water for irrigation.

at levees of plots), irrigated water will flow into plots.

On the other hand, farmers usually don’t want to spend

Flowing pattern and the amount of water is regulated bymuch time for water level management. So, it’s not

the difference between the water level of upstream canalpractical to recommend the case3. More practical way

and that of downstream canal. By changing the watermight be to find the optimum height of weir to achievelevels at the downstream of canal, how the water flow

three goals mentioned in the Material and Method. Thus,

pattern in plots will change were evaluated.

the next step is to construct a simulation model of actual

The governing equation used for the simulation is 2

case. And based on the model and observation, it isdimensional Saint Venant equations as follows.

required to find the optimum way to manage the water.

ConclusionH  H iui  Hui,i  0u  u j ui, j   u j ,i  ui, j

, j  g H  z ,i 

gn2 u
H4 3

Numerical

(1)
ui 

K W WiH

simulation

wasconducted

for

the

assessment of water distribution to plots. The results

 fui  0

indicate that if we can properly set the weir height of theirrigation canal, homogeneous water distribution to each

Here, H: water depth, u: velocity, : kinematic
viscosity, g: gravitational acceleration, n: roughness, W:

plot might be possible. Further combined research offield measurements and simulations are required.

wind velocity, f: Coriolis force. Calculation scheme is the

Acknowledgement

finite element method with two step explicit method

To conduct the research, JSPS grand-in-aid No.
16H05799 support was indispensable. And the authors
gratefully thank to the Kitai Sekkei to provide theelevation survey data of the study site, and Prof.
Masumoto of NARO to provide simulation code.

propose by Kawahara et al. (1978), and customized forflood simulation by Hai et al. (2008).

Reference
1) Kawahara M, N Takeuchi, T Yoshida (1978): Two step
explicit finite element method for Tsunami wave
propagation analysis, Int. J. Numer. Meth. Eng. Vol. 12,
pp.331-351
2) Hai P T, T Masumoto, K Shimizu (2008):
Development of a two-dimensional finite element model
for inundation processes in the Tonle Sap and its
environs, Hydrol. Process. 22, pp. 1329-1336

Fig.3 Finite element mesh used for simulations18

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

Research on cause of KE 2/20 REC dam failure in Vietnam from view point of hydraulicfracturing
1○Duy Quan TRAN , Shinichi NISHIMURA2, Masateru SENGE2 and Tatsuro NISHIYAMA2(1The United Graduate School of Agricultural Sciences, Gifu University, Japan; 2Faculty ofApplied Biological Sciences, Gifu University, Japan.）
SUMMARY
Hydraulic fracturing is the propagation and development of cracks under the effect of water pressure. It is widelybelieved that hydraulic fracturing will occur in a fill dam when the stress in the dam is reduced to levels that are lower
than the water pressure, a condition which allows for crack propagation in the dam body. The risk of hydraulicfracturing may increase when arching action occurs due to the differential displacements of the different materials in thedam body. The aim of this study is to explain the cause of a dam failure using the finite element method. A case study,
KE 2/20 REC dam, investigates a dam that broke during the first reservoir filling at positions adjacent to the culvert. A
build-up model is taken to simulate the stress-strain state in the dam body. This research reveals that the normal stresses
around the culvert were reduced to levels much lower than the water pressure. This was due to the arching action that
was associated with the effects of the culvert and the foundation. The findings suggest that the cause of the dam failure
was related to the hydraulic fracturing phenomenon.

Introduction

through the embankment, resulting in the failure of theHydraulic fracturing has been identified as one of thedam. Similar incidents, also identified as coming frompossible causes leading to the concentrated leakage andthefailure of many fill dams especially at the first reservoir

Balderhead (England), Stockton (USA), Wister (USA),filling [2]-[3], [5]-[7], [9]-[10]. It is generally accepted

Viddalsvatn (Norway), and Teton (USA) Dams duringthat hydraulic fracturing will occur when the normal

the first reservoir filling [2].

stress at any point is exceeded by the water pressure

In addition, arching action also occurs easily around[6]-[7].

hydraulicculverts. Due to arching, the normal stresses on both

fracturing is closely related to the occurrence of archingsides of a culvert can be reduced to values that are muchaction in the dam body. Arching action often occurs

lower than the water pressure. According to fieldamong different materials, such as between impervious

observations, past research concluded that hydrauliccores and shoulders, culverts and fill soil or fill soil andfracturing is the most probable cause of leakage along

foundations [2]-[3], [5]-[6], [10]. Under loading,outlet conduits [6]. However, little attention has beenmaterials with different elastic moduli can lead topaid to arching that was brought about by the effects ofdifferential displacements and then induce arching action.

slopes excavated for the construction of culverts.

Due to this action, the stresses in fill dams can be

It is clear that dam failures due to hydraulic fracturing

reduced. Past researches indicated that an incident at theare actual potential risks. Therefore, much research in

Hyttejuvet Dam during the initial filling of the reservoir

recent years has focused on predicting the risk of

was related to the hydraulic fracturing phenomenon [3],hydraulic fracturing in earth or rockfill dams. These[5]. The arching effects in the clay core of this dam

studies can be divided into three groups [3], [10]. The

caused a reduction in the stresses to levels that werefirst relies on cylindrical or spherical cavity expansion

much lower than the water pressure. In such a situation,

theories in elastic or elastic-plastic mechanics. The

under water pressure, seepage can penetrate through thesecond is based on field or laboratory tests. The last uses

existing

theories of fracture mechanics combined with laboratory

Previous

cracksstudiesintherevealed

dam

and

that

inducestresshydraulicfracturing

mechanism,occurredatconcentration at the crack tips. As the tensile strength oftests.

soil is very small, the cracks can easily propagate

To predict hydraulic fracturing in fill dams or19

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

foundations, numerical analyses using the finite element

Observations after the failure showed that a segment ofmethod were often performed in past researches. The

the culvert had broken in the middle and that the watercomputed results of these analyses were compared withflow had then caused deep erosion in the foundation,

the results of in-situ or laboratory tests. The comparisonsapproximately 8.5 m in length in the water flow direction

showed a good agreement. In this paper, therefore, aand 3.5 m in depth. There was also no sign of seepage

finite element procedure is applied to find the cause of afrom the shoulder of the dam. At the same time, thereal dam failure as a case study.

broken segment and a part of the dam body close to the

A case study called KE2/20 REC dam failure in Vietnam

culvert were swept toward the downstream [1]. An actual

was used for this study. This dam is located in Ha Tinh

image of the dam failure is given in Pictures 1.

Province in Central Vietnam. The dam’s initial purpose
was to create a reservoir to supply irrigation water forfarmland (about 30 hectares). Construction of the dam
and reservoir were started in October 2006. After 2 years,
the dam was completed and was put into operation in
July 2008. The related structures consisted of the maindam (maximum height of 12.5 m), a saddle dam, aspillway (width of 11.2 m), and a culvert (design flow of
0.037 m3/s). After being in operation for just one year,
the dam broke in June 2009 [1], [8].
Past research concluded that the dam broke due to thepiping mechanism [8]. Even though the research
point out what happened before the seepage had formed.

Picture. 1 KE 2/20 REC dam failure
Results of in-situ surveys and experiments after the dam

The current authors inferred that the dam failure may be

failure showed that the slope of the excavation on the left

related to the hydraulic fracturing phenomenon. The

side of the culvert (looking from upstream tofocus of this study, therefore, is to explain the cause ofdownstream) was rather steep. In reality, the observed

theslope was just 1:0.5 (vertical and horizontal directions,somewhat explained the cause of the failure, it did not

damfailure

under

the

hydraulicfracturingrespectively), even less than seen in Pictures 1 and 2,

mechanism using a numerical analysis.

even though the required design value was 1:1. Figure 1

Description of the dam failureshows a longitudinal section of the dam that was

Much research in recent years has focused on explaining

idealized from the design section and in-situ observations.

dam failures due to concentrated leakage. HydraulicAccording to the geological description, the culvert andfracturing is considered to be one potential cause of

the dam were erected on a firm foundation of cracked

concentrated leakage especially at the first filling soon

and weathered rock – a kind of argillaceous slate. The

after the dam completion. The risk of hydraulicelastic modulus of the foundation was much higher thanfracturing may become higher when the normal stresses

the value of the filled soil. The physical properties of thein the dam are reduced by the arching effect and the level

filled soil and the foundation, taken from previousof the water in the reservoir rises. Past researches pointed

studies on the dam, are listed in Table 1. In addition,out that dam failures were caused by hydraulic fracturingin-situ tests on the filled soil after the dam failure

at Hyttejuvet, Balderhead, Stockton, Wister, and Teton

revealed that the embankment had not been compacted

Dams during the first impounding [2].

carefully. The real relative compaction (90.4%) had notThis research introduces a dam failure that will be usedreached the required value (95%) [1].

as a case study called KE2/20 REC dam. The dam is

Cross sections of the dam and the culvert are presented

situated in Central Vietnam. It broke at the location of

in Figs. 2 and 3, respectively. It can be seen that thethe culvert under completely normal conditions, without

culvert is a reinforced concrete circular conduit and was

the incidence of an earthquake or rain, and with anplaced on a concrete foundation bed 0.4 m in depth. The

approximately normal water level in the reservoir ofphysical parameters of the culvert materials are+30.5 m [8].

summarized in Table 1.

20

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

From the above descriptions, the current authors

foundation, arching can become severe. During the firstsuspected that the cause of this dam accident might befilling of the reservoir, the water pressure grew higher

related to the hydraulic fracturing mechanism. There

than the normal stresses on both sides of the pipe culvert;

may have been discontinuities in the filled soil adjacent

the stresses were reduced to a small value by the arching

to the culvert after the construction process. Moreover,action. Under this condition, the discontinuities acted as

due to the effect of the culvert’s shape, arching action

the initial cracks that were extended and propagated bycould have occurred on the left side of the dam. With thethe water pressure. This process might have led to the

excavation of a steep slope and a considerable distinction

dam failure.

in the elastic modulus between the embankment and the
35.00

A

Crest of parapet wall +33.0m

1(0,32.2)

Dam crest +32.2m

2(28.96,30.68)
3(36.70,27.59)

25.00

4(95,25.77)
Original ground surface

20.00

5(101.2,19.17)

15.00

1.0
9(144.41,23.19)
0.5
Bottom trench10(150.5,23.19)

6(109.7,16.74)

8(138.2,18.51)
7(130.65,16.61)

Foundation

A

10.00

Foundation

Y

5.00
0.00

11(155.01,32.2)

Normal water level +30.5m

30.00

X
O

Fig. 1 Longitudinal section and data of nodal points on boundary in numerical modeldam. The build-up analysis allows for a better simulation
29.89m5m
24.12m35.00
of the influences during construction. The results of the

30.00

1.0
2.75

25.00

1.0

analysis will show the distributions of stress and

2.5

Embankment

Original ground surface

20.00

displacement in the dam, especially at positions adjacent

Bottom trench
15.00

to the conduit, to verify the arching effect.

Foundation
10.00

Table 1 Material properties
a. Filled soil
Total density (ρ):
Dry density (ρd):
Soil cohesion (c):Angle of internal friction (φ):
Coefficient of permeability (k):Elastic modulus (E):
Poisson’s ratio (ν):
b. Reinforced concrete
Total density (ρ):
Elastic modulus (E):
Poisson’s ratio (ν):
c. Foundation
Elastic modulus (E):
Poisson’s ratio (ν):

Fig. 2 Cross section of dam (A-A)
Pipe culvert by reinforced concrete
inner diameter 0.6m
outer diameter 0.8m
Concrete
0.4m

1.0
0.5

0.35m 0.50m 0.35m
0.5m
1.2m

Fig. 3 Cross section of culvert

Numerical analysis
1. Purpose of numerical analysis
In recent years, numerical analyses using the finite
element

methodhave

beenwidelyapplied2.018 Mg/m3
1.673 Mg/m3
23.0 kPa
16o47’
6.247×10-5 m/s
16800 kPa
0.3
2.45 Mg/m3
2.4×107kPa
0.2
1.0×107kPa
0.25

in
2. Model description
A build-up analysis by FEM, using 12 successive layers

investigations of the stress-strain distribution and theseepage in dams. In previous studies on the hydraulicof fill soil, is performed to analyze the deformation andfracturing phenomenon in soil or the earth pressure on

stress in a longitudinal section of the dam which includes

buried pipes, the finite element method was often used tothe cross section of the culvert as well. Even though theyield numerical results. These results were thenshape of the culvert is symmetric, the boundary

compared with the results of either in-situ observations

conditions in this analysis are unsymmetrical due to theor laboratory tests. The comparisons showed a goodeffects of the excavation. As a result, this analysis usedagreement [3], [4]. In this research, therefore, the authors

the whole longitudinal section of the dam. In addition,

set up a plane stress build-up analysis using the finite

the elastic modulus of the foundation is much higher

element method to simulate the stress-strain state in the21Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

than that of the embankment. Thus, for the sake of

dimensions than the others in order to improve thesimplicity, this model just simulates the dam body. The

accuracy and the details of the stress distribution aroundcoordinates of the 11 main nodal points on the boundary

the culvert. The model is also assumed to be restrained atare shown in Fig. 1. The coordinates of the other nodal

the foundation. Theoretically, when these nodal points

points were calculated from the coordinates of thesewere fixed, the stress at these points was equal to zero.

main nodal points.

However, this did not simulate the actual stress state on

The finite element mesh, which consists of 641 elements

the boundary. Therefore, to improve the accuracy of theand 2121 nodal points, is shown in Fig. 4. All themodel, the nodal points between the 9th and the 10th mainelements are eight-node quadratic quadrilateral elements,

nodal points (in Fig. 1) were set up to be free in theand the elements adjacent to the culvert have smaller

horizontal direction.

Fig. 4 Finite element mesh model
model [3], [6], [10]. The model used in this study might

Results of numerical analysis

be consistent with the real dam conditions just one year

1. Distribution of displacement
Previous studies on dam failures or concentrated leakage

after its completion, because the stress-strain state in adue to hydraulic fracturing revealed that hydraulicconstruction process, the consolidation condition, and thefracturing occurs when the stresses in the dam body fall

first filling of the reservoir.

to levels that are lower than the water pressure. The risk

The displacement distribution around the pipe culvert isof hydraulic fracturing might increase with the archingalso displayed in Fig. 5. It is seen that the verticaleffect. Thus, a simple criterion for predicting thedisplacement of the fill soil columns on both sides of thepotential of hydraulic fracturing at any location in thepipe is higher than that in the column of the fill soil

dam body is to compare the normal stress with the water

above the crown of the pipe. This is because the elasticpressure at that point. This criterion was used here tomoduli of the culvert material and the foundation wereexplain the cause of the KE 2/20 REC dam failure.

much higher than the elastic modulus of the fill soil.

The deformation mesh for the dam, magnified 10 times,

Therefore, differential displacements occurred underis shown in Fig. 5. The maximum vertical displacement

loading and induced arching action adjacent to theoccurred around the mid-height of the embankment. This

culvert. This result is verification of the above

corresponds to some past researches using the build-up

suspicions.

dam body can be significantly affected by theFig. 5 Deformation mesh of analysis (scale factor = 10)

22

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

2. Distribution of stress around the culvert

normal stress distribution around the pipe culvert isAs most stresses in soil are compressive stresses, forunsymmetrical. The normal stress around the culvert wasconvenience, the sign for stresses in this research arepeak to maximum when the theta angle was equal topositive for compression stresses and negative for tensile

167.3o rather than 180o. This might due to the effect ofstresses. Figure 6 indicates the relationship of the normal

the excavation shape.

stress (σθ) and the normal stress minus the water pressure

Discussions(σθ - W) around the pipe culvert versus the theta angleo(θ ) with the sign convention of theta as in Fig. 7. The

The results of this study revealed that the cause of thenormal stresses on both sides of the culvert, especially at

dam failure may be related to the hydraulic fracturing

the bottom of the pipe, were clearly reduced and muchphenomenon around the culvert. This also confirm thelower than the stress at the top of the pipe. This might behigh risk of hydraulic fracturing adjacent to a conduit

due to the arching effect. These results are similar tothat can result in dam failure. The findings coincide withthose of past research that also addressed the cause of

the conclusions of Ngambi et al. (1998). On the otherleakage along an outlet conduit underneath a low fill dam

hand,[6]. Moreover, the results from Fig. 6 show that all of themethodology and the results between this study and thestresses were still compression stresses, although theprevious research on the dam failure. Our analysis shows

normal stresses on both sides of the culvert werethat the normal stresses on both sides of the culvert weresignificantly reduced by the arching action. This is

reduced considerably by the arching effect. However,slightly inconsistent with the results of previous researchthese stresses were still compression stresses (as in Fig.

[8].

6). Thus, there may have been no tensile cracks on the

there

are

significant

differences

in

the

left side of the dam; this differs from the conclusions
drawn in the previous research on the dam failure [8].
The results in this analysis confirmed that thestress-strain state around the culvert was affected
remarkably by the shape of the culvert. In addition, theslope of the excavation also had an effect on the archingaction. This research is thought to be the first study thatelucidates the KE 2/20 REC dam failure under the
viewpoint of hydraulic fracturing. It suggests thathydraulic fracturing may occur easily around the culvert
Fig. 6 Graph of stress around pipe culvert versus
theta angle (θo)

in a dam body. Therefore, it is necessary to consider therisk of hydraulic fracturing in the design andconstruction processes of culverts underneath fill dams.
Simultaneously, countermeasures to prevent the potential
risk of hydraulic fracturing should be proposed.

σθθ

Besides the positive aspects of this research, the contact
behavior between the fill soil and the foundation or theconcrete culvert, that have an elastic modulus that ismuch higher than the embankment’s, has not been
considered for the models employed in this analysis. This
could lead to slight errors in the calculation at some local

Fig. 7 Convention of theta angle (θo)
As detailed in Fig. 6, when the theta angle is smaller thanpoints. Future studies, therefore, will aim at using better

96.0o and higher than 248.7o, the normal stress is reallymodels to simulate the stress-strain state of the case study.

exceeded by the water pressure. It can be concluded that

In addition, some countermeasures to reduce the risk ofhydraulic fracturing may have occurred in these regions.

hydraulic fracturing adjacent to the culvert will proposed

This coincides with the inferences of this early research.

as well. Another numerical analysis will also be used toMoreover, the results from Fig. 6 also indicate that thecheck the effectiveness of the countermeasures.

23

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

Engineering Innovation & Research, Volume 5, Issue 1,
2016, pp. 136-142.
[3] Mohsen, S. and Faghihi, D., Predicting HydraulicFracturing in Hyttejuvet Dam, International Conference
on Case Histories in Geotechnical Engineering, August.
2008, Paper 40.
[4] Mosadegh, A. and Nikraz, H., Buried pipe response
subjected to traffic load experimental and numericalinvestigations, International Journal of GEOMATE, Vol.
13, Issue 39, November. 2017, pp. 01-08.
[5] Ng, K. L. and Small, J. C., A case study of hydraulicfracturing using finite element methods, Can. Geotech. J.
36, 1999, pp. 861-875.
[6] Ngambi, S., Nakano, R., Shimizu, H. and Nishimura,S., Cause of leakage along the outlet conduit underneatha low fill dam with special reference to hydraulicfracturing, JSIDRE, No. 188, 1997, pp. 93-102.
[7] Ngambi, S., Shimizu, H., Nishimura, S. and Nakano,R., A fracture mechanics approach to the mechanism of
hydraulic fracturing in fill dams, Transactions of the
JSIDRE 195, 1998, pp. 47–58.
[8] Nguyen Chien and Ho Sy Tam, Analysis causes ofdam break of KE 2/20 REC dam - Ha Tinh province,
Journal of Water Resources & Environmental
Engineering, Special Issue, November. 2009, pp. 86-91(In Vietnamese).
[9] Nishimura, S. and Shimizu, H., A study of themeasurement of fracture toughness in cohesive soil –relationship between the size of initial crack anddiameter of specimen, Paddy Water Environ (2004) 2,
2004, pp. 27–32.
[10] Wang, Junjie., Zhang, Hui-ping., Zhao, Ming-jie.
and Lin, Xin., Mechanisms of hydraulic fracturing incohesive soil, Water Science and Engineering, Volume 2,
Issue 4, 2009, pp. 95-102.

Conclusion
Base on the above study, the following conclusions canbe made:(1) Hydraulic fracturing can occur easily when thenormal stresses on both sides of a culvert are reduced by
the arching effect to be lower than the water pressure.
This phenomenon may have been the original cause of
the KE 2/20 REC dam failure before the dam was broken
by piping mechanism.
(2) The culvert shape has a significant effect on initiatingarching action. Moreover, an excavation with a highslope will contribute to even more serious arching.
Therefore, a dam with the unreasonable culvert shape orhigh excavated slope might have high risk of hydraulicfracturing.
Dam failures due to hydraulic fracturing can lead tosevere damage to the downstream areas. Therefore,
measures against hydraulic fracturing are really
important in terms of ensuring the safe working
conditions of dams. The focus of future work will be toresearch other countermeasures for preventing hydraulicfracturing and the effects of an excavation slope onarching action.

Acknowledgement
The authors would like to acknowledge Prof. Dr. Nguyen
Chien, Dr. Ho Sy Tam, and Ha Tinh of the Hydraulics
Construction Consultant Joint Stock Company - Vietnam
for providing valuable input data for this research.

Reference[1] Institute of Civil Engineering, Report of analyzing
causes of KE 2/20 REC dam failure - Ha Tinh province,
2009 (In Vietnamese).
[2] Khanna, R and Chitra, R., Hydraulic fracturing incore of earth and rockfill dams, International Journal of24Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

Characteristics of Denitrification in an Agricultural Drainage Channel○Keigo Mutoh*, Ken Hiramatu*, Takeo Onishi* and Tharngika Ranatunga**(* Faculty of Applied Biological Sciences, Gifu university）(** United Graduate School of Agricultural Science, Gifu University)
SUMMARY
Denitrification is a part of purification process to remove nitrogen from ecological and environmental system in thenitrogen cycle, which is an essential phenomenon from a viewpoint of environmental sustainability. Thoughdenitrification in tidal flat, the bottom mud of lakes and paddy field that are often in anoxic condition has been
discussed frequently thus far, an agricultural drainage channel was unconsidered as a place of denitrification because of
its abundant reaeration. In this study, we focus on the denitrification from an agricultural drainage channel, especially in
non-irrigation period, because its discharge remarkably decreases during the period and then anoxic condition mightoccur for its rich organic matter on the channel bed. N2O emission from the undisturbed cores of the bottom mud wasmeasured in the laboratory by applying acetylene gas inhibition method. The results suggest the amount of nitric gas
emission from the agricultural drainage channel is not negligible and sometimes not less than that from tidal flats.

denitrification from the channel clear and to prove how

Introduction

much the nitrification by the channel contributes toSince the invention of Haber-Bosch process a large

purify the water environment quantitatively.

amount of nitrogen compounds such as fertilizers has

Material and Method

been produced and distributed in the natural and human

Our investigation target is Ooe drainage channel

environment. Some are consumed appropriately in theflowing through Aichi prefecture, Japan. It is a concrete

field, but excessive nitrogen left in the environment often

lining channel and so the bed is obviously flat by cement.

induces various environmental problems, for example,

However, fish pools that are 20m long reach deepened byeutrophication and various plankton blooms. In theapproximately 0.5m compared with the adjacent reaches

nitrogen cycle most of nitrogen is taken from atmosphere

are installed for every 500m of the channel to preserveby fixation including above mentioned Haber-Bosch

its aquatic ecosystem. In addition, several fish-nest

process and it is finally released into atmosphere throughblocks that are a kind of cavities on the sidewall area reduction process called denitrification. So theinstalled in the fish pools (Fig1). While the sediment that

denitrification is essential to drive the nitrogen cycle andis rich in organic matter is flushed by the running waterto purify the excessive nitrogen pollution in ourfrom and on the flat bed, it sinks and accumulates in theenvironment.

fish pool due to its slow velocity.

A number of studies regarding the characteristics ofdenitrification are carried out for tidal flats, lakes andpaddy fields, but there are few for lotic waters such as
rivers and channels. It is because abundant oxygen due toreaeration in the lotic waters is considered to disturb the
denitrification process. We, however, consider thenitrification might occur even in the agricultural drainage
channel, because the reaeration reduces during thenon-irrigation period and the bottom mud or sediment of
the channel includes abundant organic matter due toFig. 1 Cross-section of the Ooe drainage channel atexcessive fertilizer and agricultural residues.

a fish pool reachIn this study we try to make the characteristics of25

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

In order to evaluate the characteristic of denitrification

denitrification bacteria. In anaerobic condition, thesein the drainage channel, especially for the fish pool,bacteria use nitrogen as an electronic receptor but inphysical factors of the drainage channel (water

aerobic condition, they can use oxygen. To understandtemperature, water depth, weather) were measured on

the characteristic of denitrification in the agricultural

site and water and sediment core are sampled at two fish
pools (points A and G). The water quality indices (nitrate,
nitrite and ammonia ions), N2O flux from the cores kept
in an incubator and the amount of organic matter(ignition loss) in the sediment were measured in thelaboratory.
The acetylene inhibition method was adopted tomeasure the released nitric gas from the cores (Tiedje etal., 1989; Iida et al., 2007). The method suppresses
nitrous oxide reductases that further reduce N2O into N2
gas and also inhibits the production of NO3− via
nitrification (Iida et al., 2007). The N2O flux wasmeasured every 2 hours during 8 hours after sampling
the undisturbed cores of sediments using a gas

Fig2.

chromatography (GC-2014 equipped with an ECD

nitrogen in water (point A)

Concentrationofdissolved

inorganic

detector; Shimadzu Co., Ltd.).
The sampled water was filtered through membranefilter of 0.45 μm pore size and cast into an ion
chromatography (ICA-2000; TOA-DKK Co., Ltd.) to
identify the NH4+, NO2−, and NO3− concentrations.

Results and Discussions
Figures 2, 3 and 4 show the concentration of dissolved
inorganic nitrogen, the ratio of organic matter (ignitionloss) in the sediment and the N2O fluxes from the coresof the sediments at point A, respectively. (The results atpoint G will be shown in the presentation.) As seen fromthe data, the characteristics of gas emission at points A
and G seems slightly different, which might be due to thedifference in the amount of organic matter. The

Fig. 3 Organic content in sediments (point A)

concentration of dissolved inorganic nitrogen decreases
in summer (irrigation period) in which amount ofdissolved inorganic nitrogen must be diluted by large
discharge of irrigation. Some periodical fluctuation isseen in the ratio of organic matter in the sediments. We
could

not

identify

thecorrelation

among

the

concentration of dissolved inorganic nitrogen, the ratioof organic matter and gas fluxes by denitrification
precisely, but it becomes clear that the denitrification
ability of the drainage channel become greater or equal
to that from tidal flats and lakes. (e.g. the average gas
flux in tidal flats in Ariake sea in Japan is about
13mgN·m-2·d-1; Koga et al.,2009).
Denitrification is a phenomenon in which nitrate isFig. 4 N₂O gas flux from sediments (point A)

reduced by a specific group of microbe called26

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

drainage channel, precise concentration of dissolved

Professor Fusheng Li of Faculty of Engineering, Gifu

oxygen and the biota of nitrification bacteria should be

University, for their advice on our research experiments.

examined in addition to the current data (Groffman et al.,The authors are grateful to Mr. Sakakibara, T., Mr. MD.

2015).

Asmaul Rizal and Mr. Okada, T. for their support. The

Conclusion

authors received cooperation in various aspects of the

In this study, it becomes apparent that the potential

study

nitrification in the lotic water, i.e., agricultural drainage

Administration Ofﬁce of the Ministry of Agriculture,channel with abundant organic sediments is not less than

Forestry and Fisheries and the Miyata Irrigation Land

that lentic waters such as tidal flats or lakes. For several

Improvement Organization.

decades, natural purification of lotic water has been

Reference

mainly discussed on the decomposition of organic matter

1) Groffman, P. M., Robertson, G. P. (2015) Nitrogen

like the Streeter-Phelps model and not discussed ontransformations.

Soilnitrification. The results obtained in this study indicatesbiochemistry.

Fourththe purification process is much more complex thanBurlington, Massachusetts, USA. 421-446.

thought previously and denitrification plays an important2) Iida, T., Deb, S. K., Kharbuja, R. M. (2007). Nitrous

role also in the lotic waters. Moreover, it suggests thatoxide emission measurement with acetylene inhibition

the design of agricultural drainage channel could not be

method in paddy fields under flood conditions. Paddy

considered by only focusing on the aquatic ecosystem

Water Environ., 5: 83-91.

conservation and the biological diversity, but also

3) Imai, T. (2016) Nitrogen dynamics and denitrification

nitrogen cycle, in other words, natural purification of thein an agricultural drainage channel. Bachelor’s thesis,

water. Finally, it is necessary to examine more

Gifu University, 34p.(in Japanese)environmental factors to clarify the characteristic of4) Koga, A., Seguchi, M. and Koriyama, M. (2009)

denitrification in the drainage channel, because of its

Studies on habitat distribution of denitrifiers andinherent complexity of nitrification in physical, chemical

denitrification activity in the tidal flat of the interior parts

and biological aspects.

of the Ariake Sea. Trans. JSIDRE, 77(2): 121-128.

Acknowledgement

5) Owaki, A. (2015) Denitrification characteristics inThis work was supported in part by JSPS KAKENHI

Ooe agricultural drainage channel. Master’s thesis, Gifu

Grant number 15H04567 and also by the New Energy

University, 44p. (in Japanese)and Industrial Technology Development Organization

6) Tiedje, J. M., Simkins, S., Groffman, P. M. (1989).

(NEDO) under the Ministry of Economy, Trade andPerspectives on measurement of denitrification in the

Industry of Japan. In addition, we are thankful tofield including recommended protocols for acetylene

Professor Toshiaki Iida of The University of Tokyo andbased methods. Plant Soil. 115: 261–284.

27

from

the

Tokai

Regional

microbiology,
edition.

Agricultural

ecology

AcademicandPress,

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 201728

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

Alternate Wet and Dry irrigation technique – an adaptable solution to climate change
for rice cultivation in the Red River Delta, Vietnam
Dinh Thi Lan Phuong,
Faculty of Environment, Thuyloi University, Vietnam
SUMMARY
Rice production in Vietnam has consumed a huge water every year. Irrigation water for agriculture is becoming
increasingly scarce under climate change impacts. Alternate Wet and Dry Irrigation (AWDI) with a controlledwater level of 2÷3 cm from the surface, an irrigation schedule of 10 wet days alternated with 3 dry days andkeeping 7÷10 dry days at the last branching stage is a proposed solution. The paper reviews previous research
results in the access adaptation of this irrigation solution applied in the Red River Delta, Vietnam. The AWDI hassignificantly increased water use efficiency in the Red River Delta, uses less water (0.25 billion m3/year saved)
without significant reduction in grain yield (6.68 t/ha) compared with conventional irrigation (6.8 t/ha). Besides,
the AWDI may well reduce the green gas emissions (CH4, NO2, CO2…) in the rice fields and increase aerobic
microorganisms density in root region, therefore control soil toxic such as Fe (II), Mn (II). Due to drying aerobic
time, AWDI has a greater potential to supply necessary nutrient supplements to soil compared with conventional
irrigation method. Transformation of nutrients N, S and Zn, etc. from fixation to more mobile behavior in soil isalso advantages of this irrigation solution applied in the Red River Delta, Vietnam.
Keywords: Alternate wet and dry irrigation (AWDI), Water saving, Water use efficiency, Nutrient transformation.

inertias periods due to low water level, the water

1. Introduction

resource for 5 years from 2003÷2007 was lower from
Vietnam has been seriously affected by climate change.

9÷20 % than each year. The water level of Red River

Annual average temperature rises about 0.5 oC leadingin Ha Noi region has a low level at 22 %, sometimes

to reduce significantly cool air frequency during two

under 30 %; especially the water level was under

decades and strengthen hurricane. The results of the50÷60 % in the dry season (Ministry of Natural

climate change contributed to increasing the seawater

Resources and Environment of Vietnam, 2016).

lever about 20 cm within 50 years (Ministry of Natural
Resources and Environment of Vietnam, 2016).

To deal with the reduced water amount and quality, theFurthermore, the climate change caused to change

irrigation solution for plants awards to a saving waterflow regime, increase water evaporation and reduceand reduces greenhouse gas emissions to be one of thegroundwater level. As estimated, the groundwater

useful solutions to adapt climate change. Because ricelevel can be reduced dramatically in the dry season

is a main crop type in The Red River Delta andafter 2020. If the flow in the dry season in the Mekong

Mekong Delta of Vietnam, with average irrigation

Delta reduces by 15÷20 %, the groundwater can belevel of 5÷7 cm, consuming water for 7 million

lower 11 m compared with current flow. In the last 5

hectares of rice area were about 52.5 billion m3/crop

years, reducing surface water resource in the dry(Tran Viet On, 2016). Thus, the solution of saving

season, irrigation water deficiency, drought and salt

water irrigation awards a low carbon economy,

intrusion are faced problems in downstream river

protected environment, and sustainable development

basins. Some sections of the Red and Thao rivers had

is very necessary for Vietnam.

29

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

Although the AWDI was encouraged by The

periods. Since surface dried, supply irrigation water toGovernment, however, this irrigation technique has

5 cm immediately. As a result, keeping moistening

been applied in some regions as Phu Xuyen, Thuong

time was maintained from the seedling stage to theTin, Ba Vi (Ha Noi), Nam Sach (Hai Duong), Quynh

harvesting stage without any drying field times. The

Hong (Nghe An). Besides that, research about AWDI

AWDI technique with the highest water level 5 cm,

in Vietnam indicated that the positive effects of thishowever, the drying field time was implemented fromtechnique, including, saved water (1,995 m3/ha),

3 to 9 days between irrigation times. Thus, the AWDI

maintained

emission,creates an aerobic paddy field in a long time torestricted some pests to rice (Nguyen Viet Anh, 2009,

promote humus-forming and mineralizing processes inTran Viet On, 2016, Nguyen Xuan Đong, 2008). Thus,

the soil environment.

yield,

reducedmethanethis paper proposed some saving water irrigation

Beside of controlling water level, rainwater storage insolutions for rice in the Red River Delta climate

the fields was applied in some regions in Vietnam. Bychange adaptation.

research were conducted in the Liem Tuyet region (HaNam province) in continuous years from 2005 to 2008,

2. Materials and methods

rainwater utilization was proposed by Nguyen Xuan
This paper reviews the sustainable irrigation solutions

Dong with different storage levels, including, 5 cm, 10

for rice cultivation in The Red River Delta based on

cm, and 15 cm. The research indicated that thethe researched results.

rainwater storage effects on the total amount of

The article’s content focuses on performance

irrigation water during crop season (Nguyen Xuanevaluation of saving water irrigation techniques in theDong, 2008).

Red River Delta under aspects of water save,

3.2 Saving water irrigation technique,greenhouse gas emission mitigation and rice yield. As
results, suitable irrigation solutions are proposed toincreased water use efficiency

apply to rice cultivation in the Red River Delta under

Research results of Nguyen Xuan Dong showed thatclimate change condition.

the continuous moistening irrigation saved 326.33

3. Results and discussion

m3/ha while the AWDI saved more than two times(794.5 m3/ha) (Nguyen Xuan Dong, 2008). Although

3.1 Introduction to rice conventional

the AWDI allowed rainwater storage levels of 5 cm,

irrigation methods in the Red River Delta

10 cm, and 15 cm, however, both of 10 cm, 15 cm
storage levels had affected yield because of preventing

Conventional irrigation is a popular technique applied

diffuse oxygen in the soil to increase toxic H2S, S2-,

to most of the rice cultivation areas in The Red River

HS-, Fe2+, Mn2+ for rice roots leading to decreased

Delta. The water level was kept above 5 cm from theyield (S. Yoshida, 1981). Therefore, the storage levelsurface in all growing rice stages. Therefore, the fieldsof 5 cm is the best rainwater storage solution to rise

were only drying at the harvesting stage. The saving

effects on water use also yield.

water irrigation has two irrigation technique, including,continuous moistening irrigation and Alternate Wet

Field experiments with rainwater use indicated that theand Dry irrigation. The continuous moistening

moistening irrigation with a storage level of 5 cm

irrigation includes the highest irrigation level at 5 cm

saved 553.5 m3/ha/crop, while the AWDI saved

and a dried field from 5 to 0 cm between irrigation

1,598.75 m3/ha/crop. The water was saved from the30

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

AWDI nearly one-third of total irrigation water per a

The experiments about different irrigation levels were3

crop (Nguyen Xuan Dong, 2008) (804.25 m /ha). Thus,

conducted in Phu Xuyen region (Ha Noi) by Nguyen

rainwater storage with the 5 cm level on the surface

Viet Anh. An irrigation level of 2-3 cm with drying

was not only saved water but also protect the soil

field 2-3 days between irrigation periods and drying

environment from water logging and toxins.

field about 7-10 days at last branching stage to reduce
12.2 % of methane gas emission and increase 4.5 % of

On the other side, drying field time had influenced onyield more than flood irrigation (Nguyen Viet Anh,irrigation level by the irrigation amount. Four2009).

irrigation experiments, including, the continuous
moistening irrigation, the AWDI at level of 3-5 cm

The saving water irrigation (SWI) has researched bywith 3 drying days (AWDI -3), the AWDI at level ofmany authors in the world since 1980. Research results

3-5 cm with 6 drying days (AWDI -6) and the AWDI

of Sandhu (1980), F.N. Ponnamperuma (1985), IRRI

at level of 3-5 cm with 9 drying days (AWDI -9) were(1991-1998), Bhuiyan (1992-1993), Tabbal (1992),

conducted by Tran Viet On in Thuong Tin (Ha Noi,

Kijne (1994), Bhuiyan and Tuong (1995), MaoZi

Dan Phuong (Ha Noi) and Quynh Luu (Nghe An)(1996) and Anbumozhi (1998) showed that the SWI

regions. A drying field times include between

saved about 10÷17 % and increased about 20÷27 %irrigation periods and the last branching stage (Tranyield than flood irrigation.

Viet On, 2016).

Because of the irrigation level of conventional rice

The results showed that there is an irrigation levelproduction of Farmers in The Red River Delta isdifference between the methods. The details, thealways higher than 5 cm and over 7-10 cm in the rainy

AWDI-3

consumed

about

78.46

m3/ha

less

season. The fields were dried before harvesting 10

22.81÷39.3 % than flood irrigation. In addition, thisdays.

irrigation technique reduced about 8-9 times ofcontributed to consume significant water. For example,

irrigation water and increased more 0.4÷4.2 % yieldkeeping water level from 7-8 cm increased 200÷300

than flood irrigation. Both of AWDI – 6 and AWDI -m3/ha, nearly about 1,400÷2,100 m3/ha/crop more

9 reduced significantly 32.93÷38.56 % than flood

than the flood irrigation with the water level of 5 cm,

irrigation, however, the drying field in a long time led

while rice yield remained. Consequently, the floodto lack water for the rice to inhibit the metabolic

irrigation increases anaerobic soil environment toactivities as well as leaf growth, and tillering.

release the toxins for roots.

Furthermore, this phenomenon had become clear in

By 2016, there are about 1.8 million Vietnam’s

the sunny season to cause reducing 10.55 % yield in

Thus,

the

conventional

rice

cultivation

farmers applying AWDI to the total area of 395,000

the AWDI – 6 and 18.25 % in the AWDI – 9 (Tranhectares in different areas (Tran Viet On, 2016). The

Viet On, 2016). So, the results have shown that the

total cultivation area in the Red River Delta is about

AWDI – 3 is a useful solution.

557,000 hectares with an average yield of 65.7

Although a water control of the continuous moistening

quintals per ha. However, the AWDI is only applied

irrigation (CMI) with a returning irrigation after

about 2 % per total areas in some regions, such as Phu

drying field. However, this irrigation type reduced

Xuyen, Thuong Tin, Ba Vi (Ha Noi), Nam Sach (Hai

only 5.82 % than flood irrigation (Tran Viet On, 2016),

Duong).

which was less 4 times the AWDI – 3. Further, CMI’s

Estimated by the irrigation level is applied over 557.7

yield was not reduced 0.56 %.

thousand hectares, the amount of effective water is31

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

over 1 billion m3 per crop. According to National

cm to ensure anaerobic status for the microorganism

Environment Report 2016, the total useful capacity ofactivity (Xianqing Lin et al., 2011).

the reservoirs in Vietnam is 37 billion cubic meters of

The methane emission rate is inversely proportional towater (accounting for 4-5 % of total annual surface

mobile manganese and Eh (F.N. Ponnamperuma, 1985,

water volume), in which The Red River and Thai Binh

Nguyen Huu Thanh, 2011), but correlated with waterRiver basins account for over 45 %. Wastewater waslevel (Xianqing Lin et al., 2011) and organic content

estimated about 2 billion m3 per year, accounting forin the paddy soil (Bouman et al., 2005). In addition,

9 % total reservoir water in The Red River Delta. As a

the AWDI created favourable conditions for oxygen

result, the AWDI with the water level of 2-3 cm andentering the soil to limit the anaerobic decomposition

drying field 3-5 days between irrigation periods,of organic matter into methane (Bouman et al., 2005,

especially drying field 7-10 days at last branching

Tran Viet On, 2016). If the fields were dried at the laststage was considered to apply. If this solution appliedbranching stage and after 15 days of seeding stage withon total cultivation areas of The Red River Delta,

the regular water level of 5 cm, amount of CH4

significantly saves irrigation water around 0.25 billion

emissions reduced about 10 % (45.7 kg/ha/crop,

m3/crop while remains rice yield.

respectively). Furthermore, this method increases rice

reducingyield about 3 % (515.3 kg/ha/crop) compared with thegreenhouse gas emissions and protecting

continuous flood irrigation (5 cm) (Tran Viet On,

3.3

Irrigation

methodfor2016).

the paddy soil

In New Delhi (Indian) (Jain M.C et al., 2000)
Effects of flood irrigation on the paddy soil

concluded that the amount of greenhouse gas fromenvironment were studied by many authors in theapplying AWDI field was less than from floodworld. S. Yoshida and M.R. Chaudhry (1979)

irrigation field. The saving water irrigation with aconcluded that, wetlands are a favorable environment

drying field in the semi-tropical conditions CH4

for the decomposition of organic matter by anaerobic

emissions varied between 14 ÷ 18 kg/ha/crop, reduced

bacteria. This is the main cause of greenhouse gas

28 % compared to the flood irrigation. However,

emissions (CH4) and toxins (CH3SH, H2S, HS-, S2-)

different varieties also effected on emissions gas, the(Shouichi Yoshida & M.R. Chaudhry, 1979, S.

research indicated that decreasing methane emissions

Yoshida, 1981).

from the Pusa-169 variety was higher than the IR72

With a flood level of 5-7 cm is applied popular tothat 28 %. On the other hand, using organic fertilizer

paddy soil in some regions of The Red River Deltaalso increase greenhouse gas emissions about

released an amount of methane gas on the acid12÷20 %.

alluvium soil about 278.5÷677.1 kg/ha and on the

Research of Thuy Loi university (Vietnam) was

neutral alluvium soil with 348.5÷738.9 kg/ha (Nguyen

conducted in some regions of The Red River Delta, the

Huu Thanh, 2011).

Centre of Vietnam, and The Me Kong Delta about the

Nevertheless, the regular flood irrigation with a watersaving water irrigation from 2009-2011 with thelevel of 6 cm, as a result, parameters including oxygen

variety and cultivation regime together. The purpose

gas, Eh, pH, micronutrient content, and minerals wereof the project awards for reducing greenhouse gas

reduced more than the AWDI with a level under 3 cm.

emissions in the climate change condition in Vietnam,

More, applying AWDI with the water level is under 3

the results showed that, the AWDI with water level of32

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

3-5 cm contributed reducing methane emissions to beharmful Fe (II), Mn (II), H2S (Shouichi Yoshida &about 20.4÷34.6 % during Spring and 16.31÷37.71 %M.R. Chaudhry, 1979, Tran Minh Nguyet, 2013, Dinh

during Summer compared to flood irrigation withThi Lan Phuong, 2015).

water level of 5-7 cm. Amount of methane emissions

Studies about the AWDI in the fluvial neutral soil inwere 262.97÷355.76 kg/ha/crop and 357.30÷390.71

Tien Lu region (Hung Yen province) indicated that,kg/ha/crop in the spring and the summer seasons,after transforming flood field into a dry field, the redox

respectively.

potential increase from -198 to -111 mV and sulfate

Especially, the water level was 2-3 cm drying time 3-

concentration rise too. Clearly, the Eh and sulfate

5 days between irrigation periods decrease 10.11 %content have a proportional relationship, when Ehmethane emissions compared to flood irrigation withincrease 10.73 mV leading to the sulfate concentrationa level of 5 cm (Nguyen Viet Anh, 2009).

rise 0.07 mg/100g (Dinh Thi Lan Phương, Tran VietOn, 2015).

In addition to methane emissions, there are othergreenhouse gases such as CO2, NO2. These gases also

F.N. Ponnamperuma (1985) demonstrated that flood

reduce emissions when applied to alternate wet andirrigation reduced mobile zinc in the paddy soil.

dry irrigation. The project of greenhouse gas emission

Experiments with waterlogged clay soil in Louisiana

reduction in Agriculture was conducted by the(pH = 4.8; organic content 2.8 %) showed that theVietnam Academy of Agricultural Sciences in Van

mobile zinc concentration reduces from 0.3 to 0.09-

Noi region (Ba Vi district, Ha Noi) in 2015, showed

0.08-0.03 ppm after 2-4-6 weeks.

that with an irrigation level of 2-5 cm and drying field

Rice farming in the Red River Delta using

2-3 times per crop reduced greenhouse gas emission

conventional flooded irrigation at the level of 5-7 cm

by 25÷30 %, CH4 14÷21 %, NO2 15÷22 %, CO2

formed a reduction environment to reduce sharply the22÷27 %. In addition, fertilizers and plant protection

redox potential from -203 to -256 mV after flooding in

products also reduced dramatically in applying thea long time. Besides, pH reduced from 6.69 to 6.21

AWDI such as down 20÷28 % nitrogen fertilizer andmay be harmful for rice growth. Mobile sulfur content

39÷62 % cost of plant protection products.

reduced from 11.26 to 10.89 mg/100g (Dinh Thi Lan

Besides reducing greenhouse gas emissions, thePhuong,

AWDI also reduces Fe (II) and Mn (II) toxins to the0.055±0.001 mg/100g soil when the Eh reduced 10

rice root (Tran Minh Nguyet, 2013). In the wetland,

mV. After 8-week flood soil, mobile zinc reduced

the oxidation of Fe

3+

4+

mobilezincdecreased

about

were reduced to toxic

about 6.6 times from the original (Dinh Thi Lan

Fe and Mn . In contrast, drying field in the AWDI

Phuong, Nguyen Thi Hang Nga, 2016). Furthermore,method creates to anaerobic soil to increase the redox

regular wetlands at 5 cm also reduce availability

potential Eh to limit some toxic Fe (II) and Mn (II)nitrogen (Quyen Thi Dung, 2015).

2+

and Mn2016),

2+(F.N. Ponnamperuma, 1985).

In addition to protecting the soil environment, theCompared to the conventional flood irrigation, the

AWDI also reduces fertilizer costs by 15÷30 %,AWDI has a long time for drying field (3-5-7 days) tocreating rice quality with a nitrate content of 4.97÷6.76

create small cracks on the surface of the field, this

mg/kg, which is lower than allowed by the World

process helps to diffuse deeply oxygen to the soil to

Health Organization (Can Tho University, 2014).

anaerobic microorganism metabolism (N, S) into theThus, applying AWDI not only save water but also

nutrients in rice (NO3-, SO42-) and reduce toxins

reduce greenhouse gas emissions for environmental

33

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

quality improvement to award low carbon agriculture.

SRI crop practices on hybrid rice, 178, Paddy
Water Environ, 9:163–180.
7) Tran Minh Nguyet, “Study on the effects ofAgroforestry irrigation regime on Mn and Fe
metabolism in wetland rice soil”, 2013, (PhD
thesis, Vietnam).
8) Tran Viet On (2016), The saving water irrigation
for rice, Ha Noi, Vietnam, 2016.
9) Dinh Thi Lan Phuong, Tran Viet On (2015), The
redox potential and dynamic of sunfur in thefluvial paddy soil in Tien Lu region, Hung Yen
province, Vietnam. Proceeding of the annual
conference of Thuy Loi university, 2015.
10) Dinh Thi Lan Phuong (2016), Impact of flood
irrigation on sulfate concentration in paddy soil of
The Red River Delta”, journal of Water resourceand Environment Engineering, ISSN 1859:3341,
pp 3-8, 2016.
11) Dinh Thi Lan Phuong, Nguyen Thi Hang Nga(2016), Mobile zinc content in the flooding paddy
soil. Proceeding of the annual conference of Thuy
Loi university, 2016.
12) F.N. Ponnamperuma (1985), “Chemical
kinetics of wetland rice soils relative to soil
fertility”, Wetland soils: characterization,
classification, and utilization (workshop of The
International Rice Research Institute.
13) Reports of Ministry of Natural Resources andEnvironment of Vietnam, 2016.
14) Nguyen Huu Thanh et al. 2011, Methane
emissions from rice cultivation in the Red River
Delta, Journal of Science and devolopment, vol10, No 1, 165-172, ISSN 1859-0004.
15) Shouichi Yoshida & M.R. Chaudhry (1979),“Sulfur nutrition of rice”, Soil Science and Plant
Nutrition, 25:1, 121-134.
16) Shouichi Yoshida (1981), Fundamentals ofrice crop science, IRRI, Philippines, Los Banos.
269 pp.

The irrigation level under 3 cm ensures an anaerobic
condition to the active microorganism to limit toxins(Fe (II), Mn (II)) aiming to protect soil environment.
Moreover, a drying field time over 3 days helps tooxygendiffusion

deeplytomicroorganisms

metabolize minerals into important nutrients for rice.

4. Conclusion
The AWDI solution with an irrigation level of 2-3 cm
and drying field time of 3-5-7 days is the sustainableirrigation solution to suit the global climate change in
The Red River Delta, a main cultivated region in
Vietnam. This irrigation solution has many advantages,
so applying AWDI in total areas of The Red River
Delta to save about 0.25 billions m3 of water annual
year and remaining yield. In addition, the AWDI
reduces greenhouse gas emissions (CH4, NO2, CO2…)
and limits to increase global temperatures. The AWDI
with water level under 3 cm and drying field time over
3 days ensure aerobic status for microbial activity toprotect the soil environment and to limit toxins to rice.
A drying field time is the best method to utilize theavailable nutrients in the soil and avoid the use ofexcess fertilizer causing soil pollution.

5. Reference1) Nguyen Viet Anh (2009), “Studying the suitablesurface water regime to reduce methane gas
emissions in rice fields in the lowland sludge areain the Red River delta", PhD thesis, Vietnam.
2) Bouman et al. (2005), Yield and water use oftropical aerobic rice systems, Agric. Water
Manage 74, 87–105.
3) Quyen Thi Dung (2015), Influence of surface
water regime on nitrogen and phosphorus content
in rice soil in Phu Xuyen district, Proceeding of
the annual conference of Thuy Loi university,
2016.
4) Nguyen Xuan Dong (2010), “Study the effect ofalternate wet and dry irrigation to reduce theirrigation level for Ha Nam region”, PhD thesis,
Vietnam.
5) Xiaopeng Gao et al (2006), Plant and Soil,
280:41–47, Springer.
6) Lin X. Q., Zhu D. F., Lin X. J. (2011), Effects ofwater management and organic fertilization with34

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

Water Management along the YearA case Study in Pineapple Plantation under humid tropical climate of Indonesia
Afandi(Department of Soil Science, Faculty of Agriculture, Lampung University)
Jl. Sumantri Brojonegoro 1, Bandar Lampung, Indonesia
SUMMARY
Pineapple is a very unique crop. It is very sensitive to waterlogging, and could survive in dry condition, however, underwater stress, the yield could reduce significantly. The humid tropical climate of Lampung, Indonesia, had total rainfall
2600 mm /year, where dry season usually occurred from June to October, sometimes very severe with zero rainfall inAugust and September. However, in rainy season, more than of 2000 mm rainfall will be poured during November until
April, so waterlogging become severe problem, especially in flat area, and soil erosion in sloping area. Due to the facts
that pineapple crop need long periods from planting to harvesting (around 18

months), the pineapple

will face dry

season and rainy season. In consequence, in pineapple culture , irrigation and drainage would be done during its cycle
life. Irrigation were generally done in all pineapple stage, with the amount 20-30 mm/ha every 10 days using big gun
sprinkler irrigator, and applied at the moisture content in soil readily available water (RAW) or 50% of soil field
capacity. The source of irrigation water is deep well and natural

pond,

so preventing local pond from soil

sedimentation due to soil erosion in rainy season become very important. Drainage system was designed based on local
problems in each field (5-10 ha) and also in catchment scale (200-500 ha). In severe waterlogging area, natural pond
and its tributaries must be deepen to reduce water table in catchment area scale, while local drainage channel with 0.5-1
m deep between pineapple field, will be dug along the field area. The natural pond which was used to improve drainage
in rainy season, became source of irrigation water during the dry season.

Key words: pineapple, waterlogging, irrigation, humid tropical climate,

Introduction

stomata opened, and closed during the day. Due to thismechanism, pineapple is well known as drought plant

The pineapple (Ananas comosus L., Merrill) is antolerant due to the special characteristic of this plant.

herbaceous perennial plant. In Indonesia, pineapple

Bartholomew and Kadzimin (1977) showed that pineapple crop

could be harvested 15-18 months after planting, and after

could grow without irrigation in many areas where rainfall isthat it could be continued as ratoon crop for about 15

1000 mm or less, and in the tropics and subtropics potential

months. As reported by Rouffiange (1993), in Guyana,

evaporation often greatly exceeds this value. Asoegwu (1988)

pineapple cycle for first crop could be 19 months, andin Nigeria showed that increasing irrigation frequency

followed second cycle (1stratoon crop) around 12

increased growth parameters of number of leaves, D-leafndmonths, and third cycle (2 ratoon crop) for 12 months.

length and days to 50% flowering, however, potential and

The pineapple cycle depends on several factors, such as

harvested yields were reduced insize (big, medium, or small size) and type of planting

150kg/ha. Alamiada et al.(2001) showed that there was amaterial (crown, sucker), type of clones, as well as

positive effect of increasing irrigation on the natural

growing environment conditions (soil fertility, nutrient,differentiation and the timing of the fruit harvest period,

weeds, drainage).

resulting in a shortening of the plant cycle, without reduction ofirrigation when N >fruit weight, in the plots with the highest irrigation. The higher

Pineapple is a CAM (Crassulacean Acid Metabolism) plant,

irrigation also resulted in a more even distribution of the fruitin which CO2 is mainly fixed during night in which theharvest over its period.

35

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

Pineapple is very sensitive to waterlogging andneed

The climate data was analyzed using Cropwat v.8. whichgood soil drainage for root development. Bad drainage

was designed by FAO, using data from 1972-2009.

could induce the risk of plant loss from fungal pathogensof the genus Phytophthora (Souza and Reinhardt, 2007).
Min and Bartholomew (2005) showed that flooding anddrought stressed could effects pineapple yield. Plants
induced to flower with ethephon after continuous
flooding or drought stress had significantly smaller fruits
thancontrol

plants,hence

significantly

reducedpineapple fruit mass.
Due to the long period

life cycle of a pineapple, so

growing pineapple in Indonesia, which is have two
seasons, dry season and rainy season, will face either dry
season and rainy season. As consequence, irrigation will
be done during the dry season, and drainage will be done
during the rainy season.
Fig. 1. Main roots and axillary roots of pineapple
This paper discuss the water management ofpineapple

during dry season and rainy season of pineapple cv.
‘‘Smooth Cayenne”’ grown in humid tropical of

Table 1. Climate properties in pineapple plantantion in

Lampung, Indonesia, in plantation scale.

Lampung, Indonesia

Pineapple Structure related to waterMonth

Temp (0C)

RH

Wind

Sun

Rad

ETo

Min

Max

%

km/d

hours

MJ/m2/dmm/d

Pineapple has a photosynthetic adaptation (crassulacean

Jan

22.2

31.8

91

107

4.1

15.8

3.4

acid metabolism (CAM)) that facilitates the uptake of

Feb

22.2

32

90

106

3.2

14.6

3.2

carbon dioxide at night, and improves its water-use

Mar

22.3

32.4

91

83

4.5

16.5

3.6

efficiency under dry conditions (Carr, 2012). There are

Apr

22.8

32.5

91

78

4.4

15.6

3.4

relatively few stomata per unit of pineapple leaf area,

May

23.1

32.8

90

80

5.5

16

3.4

small and situated mainly on the underside of the leaves

Jun

22.5

32.4

90

82

5.4

15.2

3.2

in depressed channels, and protected by a heavy coat of

Jul

22

32.5

88

92

5.4

15.5

3.3

Aug

22.1

32.8

87

109

6.3

17.8

3.8

Sep

22.6

33.4

86

117

6

18.5

4.1

Oct

22.8

33.8

86

107

5

17.3

3.9

Nov

22.6

33

88

93

4.2

15.9

3.6

Dec

22.7

31.9

90

91

3.4

14.6

3.2

Aver

22.5

32.6

89

95

4.8

16.1

3.5

waxy trichomes, so the pineapple has a very low rate oftranspiration (DPI,2009).
There are two types of root system in pineapple, the main
root in the soil and axillary roots in the stem (Fig.1).The
axillary roots that can absorb moisture and dissolved
nutrients directly in the same way as soil roots do(DPI,2009).

The average maximum evapotranspiration (ETo) is about

Climate and Water Balance

3.5 mm/day, and with Kc around 0.89 (Azevedo et al.,The climate data consisted of monthly rainfall, maximum2007), the actual evapotranspiration from pineapple isand minimum temperature, relative humidity, and day

aroundlength which collected from PT.GGP climatology station

3.1 mm/day. As shown in Fig.2., the deficit

month occurred from May until October (6 months).

(4o49’07”S, 105o13’13”E) were presented in Fig.2 andTable 1.

36

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

Low value of pineapple evapotranspiration was found by

five stage based on its age after

Hanafi et al. (2010), which found requirementwater

vegetative growth (0-3 month after planting), fast

was found 2.43 mm/day in initial stage , and subsequent

vegetative growth (3-9 month), flowering (9-12 month),development stage

fruit formation (12-14), and fruit harvest (14-15 month).

required smaller amount of irrigationwater (approximately 1.55 mm/day).

planting: firstAs long as the irrigation water and equipments areavailable, all the stage must be irrigated during dry season.
If the water is not enough during one stage, it will effects
the following stage, and finally effects the final yield.

milimeter

300

250

Effective Rainfall

200

EvapotransIrrigation on early vegetative growth, has other objective.
The pineapple root in the soil is not developed yet,however, making contact between soil and pineapple

150

should be done in order the pineapple has a good “set100

plant”, hence have good rooting Irrigation will make the50soil disperse, so it could fill the space that might beoccurred around the base of planting material.

0

around the base of the planting material

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Month

The source of irrigation water in pineapple is from deep
Fig.2. Water balance , with pineapple Kc=0.89 andwell and natural pond. The irrigation water applied using

effective rainfall (70% of rainfall)

big gun sprinkler, with capacity of the sprinkler around 5
ha/day and rotated 180O when irrigated. If enough rainfall

Analysis of rainfall data from 1972-2014 showed that theoccurred during dry season, the irrigation will stop

amount of rainfall during dry season was from 2.3-15% oftemporary.

total rainfall in the year, mostly below 5% (Table 2). It
means that almost 95% rainfall was pour during rainy

Based on water balance analysis, the irrigation should beseason, which make soil erosion due to rainfall factor

started from May until October with the amount aroundwill be high.

90-110 mm.. The soil texture dominated in pineapple
area are clayey, sandy clay, and sandy loam, with aivalable

Table 2. Long dry season recorded 1972-2014

water 16, 9, and 20% respectively. The iirrigation wasgiven at 50% of field capacity or in readily water available

Month
Year

6

7

8

9

Total

Total

%

(RAW) or when the water is in managable allowance

Dry

Rainfallrainfalldeficite (MAD) condition. So teroritically, in 20 cm soil
depth with 10% of RAW at sandy loam soil, the amount10of water given was 20 mm. With evapotranspiration of

mm
1982

48

15

0

3

26

92

1737

5.3

pineapple around 3.1 mm/day, the pineapple should be

1991

12

8

3

6

32

61

2350

2.6

irrigated again after around 7 days.

1994

4

35

0

15

45

99

2433

4.1

1997

13

21

2

0

0

35

1557

2.3

In practice, the amount of water given was already

2002

94

99

12

7

0

210

2169

9.7

accordance the soil water avaibility, between 20-30 mm

2004

19

84

0

97

98

297

1986

15.0

2006

44

9

0

0

18

71

2263

3.1

2011

59

84

0

0

92

234

1695

13.8

per ha, however, there is still doubt about the evaporation
rate of pineapple, especially the flowering stage, because
the canopy of pineapple already almost 100% covered thesoil. The second is pineapple is a CAM plant in which thestomata closed during the day, so the transpiration should

Irrigation in Pineapple

be lower. Based on this reasons, the return period of
pineapple irrigation was done every 10 days.

For irrigation purposes, pineapple could be devided into

37

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

To see the effects of irrigation and non irrigation inis the most important factor that affecting pineapple yield.

pineapple, there was a good measurement was done using

Water logging will reduce oxygen from the soil, andLicor 6400 XT when the age of plant was around 6

change the soil situation, from oxidation to reduction, as

months by R & D PT.GGP (2011). The observation was

well as induced phytophthora disease in pineapple.

done at night from 19:00 until 22:00 during the dry season
in September 2011. The pattern of photosynthesis andPonding is the accumulation of excess water on the soiltranspiration rate were very different in irrigation and non

surface; waterlogging is the accumulation of excess water

irrigation treatment (Fig.3 and Fig 4). Under irrigationin the root zone of the soil (Ritzema et al (1996). So, thetreatment, photosynthesis and transpiration rate were

excess of water due to ponding will be remove by surface

higher, while in non irrigation treatment the process was

drainage, and the excess of water due to waterlogging willalmost stagnant. The average ofremoved byphotosynthesis andtranspiration rate at irrigation treatment were 3.39 μmol
-2-1

CO2 m s2

subsurface drainage. The other term issedimentation in the natural pond which is resulted from-1

surface runoff which induced soil erosion

and 0.32 mmol H2O m s respectively

while in non irrigation treatment only 0.03 and 0.01
respectively. The yield from sampling with the amount of

Before 2008, the pineapple crop was planted on raised

400 pineapple plants showed that the average of pineapple

bed about 1.2 m wide with double row crop (Fig.5).

fruit was 1,398 kg in irrigation treatment with different

However, there were several limitation using the bed

significantly with non irrigation treatment which only

system, such as soil erosion destroy the bed system,

1,164 kg.

sensitive to drought during dry season, and the
population is less. The raised bed system was good in
avoiding ponding or waterlogging during rainy season.
Since 2010, the pineapple was planted in row system orsingle row (Fig.6), however, fresh pineapple was still
planted in raised bed due sensitive to waterlogging.

Fig.3. Photosynthesis rate in irrigation and non-irrigation

0.45
0.4
0.35
0.3

Fig.5. Raised bed for double system in pineapple

0.25
Transpiration rate
0.2(mmol H2 O m2 s-1 )No Irrigation

0.15

Irrigation

0.1

0.05
0
-0.05

1

2

3

4

5

6

7

8

9

10

11

12

13

Measurement Interval (Every 10 seconds)

Fig.4. Transpiration rate in irrigation and non irrigation

Drainage Practice in Pineapple
In pineapple area, during rainy season, there are three
types of water that occurred due the rainfall: ponding,Fig.6. Single row system in pineapple

waterlogging, and surface runoff. Probably, waterlogging
38

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017Conclusion

Because surface and subsurface drainage is very
important in pineapple, there are several strategies toapply drainage system in pineapple

In Indonesia, pineapple culture would be faced dry and(a)sub soiler

application for counting waterlogging

rainy season, and irrigation and drainage must be

problems. Sub soiler with mole was used before

designed correctly. Although pineapple could be said asfinishing land preparation until the depth of 90 cm toxerophyte plant, irrigation was proved to be able

break out soil hardpan and making sub surface drainage.

increase its crop performance, such as photosynthesis.

However, under high rainfall, the sub soil is not effective

The pineapple was irrigated with the amount of 20-30

and the hardpan appear again 4 after planting (Fig.7).

mm with 10 days interval irrigation.

(b)surface drainage; surface drainage as well as surface

season, ponding, waterlogging and surface runoff mustrunoff, were control by making(i) tertiary channel

be control to improve pineapple crop, control soil erosion

between plot which collected water between crops as

and sedimentation as well as the accessibility of farmwell as road (ii) secondary channel, collected water fromequipment.

tertiary channel and passed to primary channel andDuring rainy

Acknowledgement(iii) primary channel. A silt trap was usually built at thesecondary and primary channel to entrap sediment from

The writer wish to thank to PT.Great Giant Pineapple(GGP), Central Lampung.

soil erosion.

Reference
1)Asoegwu,

S.N.(1998)

Nitrogenandpotassium

requirement of pineapple in relation to irrigation in
Nigeria. Fertilizer Research 15:203-210 (1988)
2)Azevedo, P. V. de, Souza, C. B. de, Silva, B. B. da andSilva, V. P. R. da (2007) Water requirements of pineapple
crop grown in a tropical environment. Agricultural Water
Management 88:201–208.
3)Almeida, O.A. de, L.F. da Silva Souza, D.H.
Reinhardt, and R.C. Caldas (2001) Influence of Irrigationon the Cycle of 'Pérola' Pineapple in Coastal TablelandFig.7. Penetrograph measurement 4 months after

Area of Brazil. Pineapple News No.8.June:10-11.

subsoiling3)Bartholomew, D. P. and Kadzimin, S. B. (1977)
The last strategy to reduce water table in catchment scale

Pineapple. Chapter 5. In Ecophysiology of Tropicalis deepening natural pond. During rainy season, natural

Crops, 113–156 (Eds P. de T. Alvim and T. T.

pond could collect rainfall which will be used as

Kozlowski). London: Academic Press.

irrigation water during dry season.
4)Carr, M.K.V (2012) the water relations and irrigation
In addition to requirement of pineapple for good soil

Requirements of pineapple (ananas comosus var.

drainage, the purpose of the drainage system in

Comosus): a review. Expl agric.: page 1 of 14.

plantation scale was to control soil erosion in the roadand sedimentation in natural pond,
farming equipment’s5)DPI (2009) The Pineapple ,Chapter 01:. Pineapple best

and the ease ofpractice manual.

transportation of equipment, such

Department of Primary Industry

Queensland Australia Government.

as tractor, harvesting’s car etc.

39

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017.

6)FAO (2009) Cropwat Version 8. FAO. Rome.
7)Hanafi, M.M., S. M. Shahidullah, M. Niazuddin, Z.
Abd Aziz and C. H. Mohammud (2010) Crop waterrequirement at different growing stages of pineapple in
BRIS soil. Journal of Food, Agriculture & Environment
Vol.8 (2): 9 1 4 - 9 1 8.
8)Min, X.J. and Bartholomew, D.P. (2005) Effects ofFlooding

andDroughtonEthylene

Metabolism,

Titratable Acidity and Fruiting of Pineapple. Acta Hort.
666; 135-148.
9)Ritzema,H.P., R.A.L. Kselik, and F. Chanduvi (1996)
Drainage of Irrigated Lands. FAO. Rome.
10)Rouffiage, N.(1993):Diaognosis Pineapple Industry
in Guyana:Major Contsraints and Perpective.IICA Officein Trinidad and Tobago.
110Souza, L. F. Silva da and D.H. Reinhardt. (2007).
Pineapple ,Chapter 10 in Tropical Fruits of Brazil ed.
A.E. Johnson. Bulletin 18 International Potash Intitute,
Horgen, 179-201

40

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

Sediment Trap using Small Farm Reservoir in Rainfed
Dwi Priyo Ariyanto1, Arif Noor Rahmadiyanto2, Keigo Noda3, Masateru Senge3, Komariah1(1Soil Science Department, Faculty of Agriculture, Universitas Sebelas Maret – Indonesia;
2
Bogor Botanical Garden – Indonesian Institute of Science;
3
Faculty of Applied Biological, Gifu University – Japan）
SUMMARY
Small-Farm Reservoir (SFR) is a method to harvest rain water while rainfall and be used while short drought
occurred. The experiment aims to measure sedimentation which flowed into SFRs from catchment area. Three SFRs
were observed from November 2013 to September 2014. Catchment of SFR-A and SFR-C are farm field which wascultivated paddy and non-rice food. Catchment of SFR-B consists of farm field, teak plantation, asphalt road andresidence. SFR-B has higher SDR than SFR-A and SFR-C. Silt particle is highest particle which can be trapped in SFRs.
Bedload sediment has higher C organic than origin catchment soil. SFR can prevent soil loss and fertility by trap the
sediment and can be returned into farm field.

Introduction

September. First crop season commonly cultivate rice,

Erosion or soil loss is a common degradation which

majority in 2nd crop season cultivate non-rice foods crop

become problem in intensive land use, like in agriculture(palawija), and last crop season few field cultivatedfield. Soil loss often occurred in rainfed cultivation and it

because irrigation rarely.

becomes serious problem because field surface is opened

Climate data along observation were collected fromand the soil explored by human which affected the soil

Portable Automatic Weather Station which installed ineasy to be transported. Although the erosion is natural

the observation area. Water level data were collected

process (Daniel et al. 2015) which can be occurred inloggers which were installed in each SFR.

everywhere as impact of run off increasing, but heavy
erosion must be prevented so that land degradation will
not be occurred (Winarno et al. 2008; Fuady, Satriawan,
and Mayani 2014). The other solution constructs
sediment trap in the field, but it is need space which canbe decrease agriculture area.
The experiment aims to measure sedimentation
which was trapped in the SFR from catchment area.

Material and Method
The observation was conducted from October 2013
to September 2014 where located in Central Java,
Indonesia (Figure 1). The location is rainfed area whichis consisting of three crop season. Those are 1st cropFigure 1: Map of observation site (Ariyanto et al.
2016)

nd

season started October to January, 2 crop season started
February to May and 3rd crop season started June to41Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

Sediment bedload sample from each SFRs wereTable 2. Soil loss balance in each SFR from
December 2013 to September 2014

taken in September 2014 or in dry season after SFRs
empty or dried by pump. Bedload solutions were taken
for sample during SFRs were dried and evaporated in

SFR-A

SFR-B

SFR-C

4,157

6,046

5,586

3

(1) Total rainfall (m )laboratory.

3(2) Suspended inflow (m )

536

589

1334

The observation was done by three SPRs in a village.

(3) Sediment inflow (kg)568.94

1,568.74

3,617.79

The characteristic each SFR is shown Table 1. SFR-A(4) Sediment bedload (kg)188.02

1,449.16

2,118.43

0.33

0.92

0.59

319.2027.82

250.06

56.10

1.77

6.91

61.72

91.76

1,249.31

10.85

5.85

34.53

SDR [(4)/(3)]and SFR-C have different in size and catchment area as(5) Sediment overflow (kg)farm field and SFR-B consist of farm field, teak[(5)/(3):%]plantation and residence.
Table 1:

(6) Sediment irrigation (kg)[(6)/(3):%]Catchment area characteristic, SFR andirrigation area size (Ariyanto et al. 2016)
SFR No.

SFR-A
2Catchment area (m )

4,184

4,068

66

132.5

182.6

Farm land(%)

Sand particle is higher than other particle fromsediment texture. It means sand particle is particles
which easy to transport by run off and settle down in

10*5*1.32 25*5*1.06 22*5*1.66

Irrigation area (m2)
232
1,733
Characteristics of catchment area
Land use

SFR-C

2,877

SFR (m3)
W (m)*D(m)*H(m)SFR-B

SFR. Diameter particle influence particles movement

2,968

and settle down in SFR.

100.0

65.4

100.0

Teak plantation

0.0

33.2

0.0

Asphalt road

0.0

0.0

0.0

Residence

0.0

1.4

0.0

Table 3. Soil catchment and sediment bedload
characteristics in each SFR
SFR-A

SFR-B

SFR-C

Catchment soil
C organic (%)

1.31

1.19

1.98

Sand (%)

25.79

52.29

18.77

Silt (%)

62.88

38.89

66.62

Clay (%)
Bedload sediment

11.33

8.82

14.61

SFR-B. It caused total catchment area of SFR-A and
SFR-C used once each year for paddy culture so that

C organic (%)

2.44

1.24

2.98

many sand particles became smaller particles. SFR-B isSand (%)

1.38

6.27

2.40

not all used for farm field, although it is dominated ofSilt (%)
Clay (%)

83.51
15.11

73.58
20.15

80.04
17.56

Result and Discussions
Soil characteristic in catchment area is dominated bysilt particle for SFR-A and SFR-C and sand particle incatchment area. The others were used for teak plantationand smaller for residence.

Sedimentation content higher C organic than soil

Result of sediment analysis shows SFR-B has higher

origin. Sediment was trapped in SFR which increase C

sediment delivery ratio (SDR) than SFR-A and SFR-C

organic. Other reason, much of organic matter, such as(Table 2). It means much sediment from catchment area

leaf, also trapped and decomposed in SFR whichflow and can be trapped by SFR. Farm field which has

increase C organic content.

terrace system can prevent soil loss from catchment area.

Conclusion

Residence and asphalt road are indicated to increase

SFR can prevent soil loss from catchment area

sediment delivery because those land use increase run off

which located upper. SFR also collect C organic which

discharge.

can be returned to the field.

42

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

Acknowledgement
This observation was support by JSPS foundation which
was support collaboration of Gifu University, Japan, andUniversitas Sebelas Maret, Indonesia.

Reference
Ariyanto, Dwi Priyo, Komariah, Kohei Yoshiyama, Ken
Hiramatsu, Kengo Ito, Takeo Onishi, Komariah, andMasateru Senge. 2016. “Small-Farm Reservoir
Contribution to Annual Crop Cultivation in Rainfed
Paddy Field under Tropical Monsoon Climate.”
Journal of Rainwater Catchment Systems 21 (2): 1–6.
Daniel, J, W J Karl, J Pamela, and E Jon. 2015. “Soil
Erosion in Humid Regions: A Review.” Journal ofContemporary Water Research & Education, no.
Horton 1933: 48–59.
Fuady, Zahrul, Halus Satriawan, and Nanda Mayani.
2014. “Runoff, Erosion and Nutrient Sediment due
the Vegetative Soil Conservation on Oil Palm
Plantation.”
Sain
11
(2):
95–103.
doi:10.15608/Fstjssa.v11i2.225.
Winarno, Joko, Dwi Priyo Ariyanto, Sri Hartati, andRetno Rosariastuti. 2008. “Kajian Bahaya Erosi Pada
Lahan Kering Di Sub Das Samin Kabupaten
Karanganyar.” Sains Tanah 5 (2): 101–6.

43

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 201744

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

Recent water management technology of rice cultivation in Japanand our future research needs○Toshiaki IIDA
(Graduate School of Agricultural and Life Sciences, The University of Tokyo)
SUMMARY
Due to a constant population movement from the rural area to the urban area, the rice production in Japan currently
confronts serious problems such as a shortage of successors and high labor costs. To cope with these problems,
entrustment of farm land to the selected pillar farmers is encouraged to increase the management scale of them. Under
this policy, labor productivity should be enhanced especially by streamlining of water management. Owing to recent
rapid development of ICT, the water management in rice cultivation can be drastically eased by making use of suchmodern technology. In Japan, various ICT systems have been developed and deployed at canal systems and also fieldplots. However, it has still been unclear how much water management work can be reduced by how much investment to
the ICT system. Actual concrete needs of farmers with regard to water management have not been investigated closely
so far. As both Vietnam and Japan live on rice, exchange of experiences and knowledge with each other andcollaborative research activity on these issues must be fruitful.

Introduction

frequency, or spreading of insect pests.

1) Rice cultivation in Japan

To cope with the above problems, the JapaneseJapan is located at the northeast edge of monsoon

central government is taking measures to promote theAsia, where the staple diet is rice. As rice has been theincrease of the management scale of the selected pillar

principle agricultural product in Japan, rice paddy fields

farmers. Especially, entrustment of farm land to the pillar

occupy 54.4 % of the total agricultural land in Japan.

farmers is strongly encouraged (Japanese Ministry ofBecause rice is grown under the flood condition, plenty

Agriculture, Forestry and Fisheries, 2016). This policyof water is required during the crop season tomust realize management of the larger area of paddy

compensate the evapotranspiration and the percolation infields by less workers, causing considerable increase inpaddy fields. The well-developed irrigation and drainage

labor per a farmer. Under the future provision of further

system have been constructed in every region to carry the

expansion of cultivation areas per a farmer, laborwater resources for rice cultivation. It is important for

productivity

farmers to maintain and control the appropriate water

streamlining of water management activities in ricecondition in paddy fields in order to get higher yield andcultivation.

shouldbeenhanced

especiallybybetter quality of rice.

Recent water management technology

2) Problems in rice production in JapanThe rice production in Japan currently confronts

1) ICT in irrigation and drainage

serious problems such as a shortage of successors andOwing to recent rapid development of ICT, it has

high labor costs. There is a constant population

become possible to instantly transmit information on the

movement from the rural area to the urban area and mostamount of available water and on the demand of farmersof the young people in the agricultural area are reluctant

interactively, making use of Internet and various field

to succeed farmhouse management. Because of thesensors (Olalla et al., 2003). It is considered that the

shortage of successors, considerable areas of farmland

water management in paddy fields can be drasticallyhave been abandoned as the farmers get old andeased by making use of such modern technology. In

eventually retired. The land abandonment would induce

future, irrigation systems should be a service providing

adverse effects such as soil erosion, increase in flood

systems for farmers and the service quality should be

45

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

further improved from a demand-oriented point of view

operated by usage of ICT (Fig.2). These ICT gadgets(Renault & Montginoul, 2003).

must reduce the patrol frequency, bringing about surplus

2) Canal systemtime for the farmers. Consequently, the farmer can be

In Japan, the canal system for irrigation andentrusted more plots from an elder farmer without adrainage is managed by Land Improvement District

successor. The surplus time also enables the farmers to(LID), which is a community of farmers who uses thelaunch cultivation of other cash crops or sales promotion,

canal water for their agricultural production. There areresulting in economic improvement of their farmhousenearly 4,000 LIDs in Japan operating headworks,

management.

diversion works, pump stations, gates and so on. It has

Our future research needs

already realized in the major LIDs that the water flow atimportant points along main canals can be continuously

In both Vietnam and Japan, the staple diet is ricemonitored and major gates or pumps can be remotely

and more than half of the agricultural land is occupied bymanipulated from the LID office or by various mobile

rice paddy fields, which require a lot of irrigation waterterminals. The system is called Tele-Meter Tele-Control

and water management labor. On the other hand, theSystem (TM/TC) (Fig.1). Many field sensors andconstant population movement from the rural area to the

networks have been deployed in the canal network. Suchurban area is observed in both country. Especially, thesystem releases the operators of the canal system fromreluctance of young people to succeed farmhousefrequent patrol works throughout the canal network.

management may be a common serious problem.
Introduction of ICT to agriculture can be one of
the solutions of this problem. Can ICT be really aneffective remedy? It has still been unclear how muchwater management work can be reduced by how muchinvestment to the ICT system. Actual concrete needs offarmers with regard to water management have not been

Fig.1

investigated closely so far. It is necessary to clarify the

TM/TC system for canal management.

critical point for reduction of water management laborand to propose effective service for farmers to ease theirwater management. In these points, there may becommon problems and the differences according to thereal situation in Vietnam and Japan. As both country liveon rice, the exchange of experiences and knowledge witheach other and collaborative research activity on theseFig.2

issues must be fruitful.

Remote controlled valve at a water inletof a paddy field plot.

Reference
1) Japanese Ministry of Agriculture, Forestry and
Fisheries (2016) Drastic strengthening of farmland
entrustment to pillar farmers/prevention of farmland
abandonment.
http://www.maff.go.jp/j/keiei/koukai/kikou/pdf/kikou_ga
iyou2.pdf (In Japanese) (June 14, 2016).
2) Olalla, F.M.de S., Calera, A., Domı́nguez, A. (2003)
Monitoring irrigation water use by combining Irrigation
Advisory Service, and remotely sensed data with ageographic information system. Agricultural Water
Management 61: 111-124.
3) Renault, D., Montginoul, M. (2003) Positive
externalities and water service management in rice-based
irrigation systems of the humid tropics. Agricultural
water management 59: 171-189.

3) Plot system
For each paddy field plot, “irrigation information
service system (IISS)” has already been manufactured inJapan. IISS gives the information on the variation of thefloodwater depth, the picture of the field plots and thebasic meteorological data directly to the farmers throughvarious information terminals. The floodwater depth ofeach paddy plot is monitored in much more shorter
interval than the conventional patrol. The spread of IISS
is beneficial for LIDs as well because a good deal of
information concerning irrigation water use can beobtained. Recently, even the water inlet valve and thedrainage valve at each paddy field plot can be remotely46Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

Co-design of adaptation to Climate Change with the current strategy in the water
management sector in Thailand–A concept for multi-criteria analysis○Keigo NODA*，Hiroaki SHIRAKAWA**, Weelakaset SUANPAGA****Faculty of Applied Biological Sciences, Gifu University**Graduate School of Environmental Studies, Nagoya University***Faculty of Engineering, Kasetsart University
SUMMARY
Climate Change is a challenge in managing risk. The objective of our study is to develop a framework to co-design anadaptation strategy. It is essential to assess the effects of policies quantitatively from various aspects, to share the resultof assessment among stakeholders, and to identify the priorities. We collected various socio-economic and naturalenvironment data. We are planning to develop a damage function which will be applied to impact assessments of CC on
human health, poverty, and economic loss. The effect of adaptations alleviating the damage in various criteria will beassessed. The expected outcome of this analysis is to identify the priority of local strategies considering regional
characteristics of natural and social conditions.

Introduction
The

Workingcharacteristics in the middle income countries and thethedeveloping countries are invaluable. Third is that

Intergovernmental Panel on Climate Change (IPCC) toadaptation to CC should be integrated with governmental

the

the

strategies of existing sectors such as disaster risk

vulnerability and exposure of human and natural systems,

management, integrated water resources management

the observed impacts and future risks of climate change,

and rural development. Furthermore, instead of theand the potential for and limits to adaptation (IPCC,

individual adaptation to CC, the well-balanced good2014). One of the key messages is that Climate Change

portfolio of the various adaptations to CC should be(CC) is a challenge in managing risk. Three points thatcomposed.

Fifth

AnnualGroup
ReportII(WGII)(AR5)

ofconsidersare important are (1)global annual economic losses are

The objective of our study is to develop a framework

estimated between 0.2 and 2.0% of income for additional

to co-design an adaptation strategy. Political or economic

temperature increases of up to 2℃, (2)co-benefits,barriers to the adaptations to CC have been raised as 1)

synergies, and trade-offs exist between mitigation andtrading cost, 2) market failure, 3) culture and customs, 4)

adaptation and among different adaptation responses, andfairness, 5) government failure and 6) prediction(3)available strategies and actions can increase resilience

uncertainty. To overcome these barriers, it is essential toacross a range of possible future climate while helping toassess the effects of policies quantitatively from various

improve human health, livelihoods, social and economic

aspects, to share the result of assessment amongwell-being and environmental quality.

stakeholders, and to identify the priorities. In this study,

Toward incorporation of adaptation to CC into

we are developing an assessment in terms of humannational master plans, there are three challenges. First,

health, poverty reduction and economic growth.

adaptation is still in the research and development

Material and Method

process. Even in Japan, the national master plan
including adaptation to CC has formulated in 2016. This

Various data were collected for the purpose ofis because the quantitative estimation of adaptation isdeveloping the assessment scheme: socio-economic data

limited. The second is that adaptation should havesuch as population, gross regional production, poverty

diversities considering local characteristics. Especially,

ratio, disaster damage and natural environment data suchcase studies of adaptation to CC considering local

as topography, precipitation, flood frequency etc.

47

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

Number of death by flood(2013)

Ratio of damage cost by flood for GDP(2013)

Poverty ratio(2013)

Fig.1 Spatial distribution of the number of death by flood, ratio of damage cost by flood to GDP and poverty ratio in 2013

Result and Discussions
As an example of collected data, spatial distributionsof the number of death by flood and ratio of damage cost

Death

GDP

Poverty ratio

Investment

Policy 1

Policy 2

by flood to GDP are shown in the left and middle ofFig.1. In Thailand, frequent flood occurs in the middle
and northeast region; the topography is very flat and theflood can be recognized as ‘inundation.’ For this reason,
the main reasons for death by flood are accidental fall ina hidden hole and electrification. Economic damage
concentrates on the Bangkok capital and industrial zonesuch as Ayuttaya and Nakhon Ratchasima.
In contrast, flash flood occurs in the northern region;

BAU

the topography is steep by mountains and the value of

Fig.2 Conceptual result for the multi-criteria analysis

poverty ratio is seriously high. The number of death isnot significant due to low population density and thehealth, poverty, and economic loss. The effect of

local knowledge to protect from flood damage.

adaptations alleviating the damage in various criteria will

Economic damage by flood is relatively high in the

be assessed. The expected outcome of this analysis is tonorthern region such as Mae Hong Son; agriculture is theidentify the priority of local strategies consideringmain industry in this region and vulnerable to flood

regional characteristics of natural and social conditions.

damage.
Conceptual result for the multi-criteria analysis is

Acknowledgement

This research was supported by “Advancing Co-designof Integrated Strategies with Adaptation to Climate
Change in Thailand (ADAP-T)” supported by the
Science and Technology Research Partnership for
Sustainable Development (SATREPS), JST-JICA.

shown in Fig.2. BAU showed a future projection basedon the business as usual. Policy 1 and 2 indicates theresult of scenario analysis in multi-criteria of the numberof death, GDP and poverty ration when the same amountof investment is embarked. This information will

Reference

contribute to decision making by stakeholders.

IPCC (2014) Fifth Assessment Report (AR5).
https://www.ipcc.ch/report/ar5/(Accessedon2017/11/02).

Conclusion
We are planning to develop a damage function which
will be applied to impact assessments of CC on human48Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

Energy use efficiency of integrated rice-duck farming in a selective area of Ha Nam province,
Northern Viet Nam○Nguyen Thi Hang NGA
Pham Thanh LAN(Faculty of Water Resources Engineering, Thuy Loi University, Viet Nam)
SUMMARY
Integrated rice–duck farming, a form of organic agriculture, has been widely applied in Viet Nam with many economic,
environmental, and ecological benefits. This is an alternative system that aims to reduce the consumption of fossil fuels,
pesticides, and mineral fertilizers as compared to conventional paddy rice cultivation. The current study was conductedin Ha Nam province of northern Viet Nam. In this study, we collected data in recent times and make comparison ofenergy inputs and outputs of organic rice– duck farming system to conventional rice production system in Ha Nam
province. Our results show that energy input of organic rice–duck is lower than that of conventional rice.

On thecontrary, the energy output of organic rice–duck is higher than that of conventional rice. Besides that, integrated
rice–duck farming has more energy efficiency than conventional rice farming. The fuel was amounted approximately to33,2 % of total energy for integrated rice–duck farming and 32 % for conventional paddy rice. The machinery
consumed 14,6% of total energy for integrated rice–duck farming and 11,2 % for conventional rice. Then, fertilizers
consumed 0 % of total energy for integrated rice–duck farming versus 21,6

% for conventional paddy rice.

Keywords: Renewable energy, Paddy rice, Rice–duck farming, Sustainable agriculture

Introduction

agriculture has also to face the problems of the emissionof trace greenhouse gases and soil characteristics

Population growth is believed to be one of the main

decline (Anh, N.V, 2010; Phuong, D.T.L 2014).

challenges for the future of human civilization

Therefore, methods of decreasing the energy needs of(Kibirige 1997; Swaminathan 2010) because of foodmodern agriculture are very necessary for agriculture

shortage caused by limited resources and the limitations

production.

ofmodernSome researchers show that the use of renewable energy

agriculture has successfully solved the problems by

may reduce the consumption of fossil fuels, saving

developing more efficient techniques, such as using

natural resources and leading to sustainable agriculture

more efficient plant and animal varieties, increasing the(Kizilaslan 2009). Organic agriculture, which has beenuse of fertilizers, extending irrigation, effectively

widely studied in recent years, is seemed to lower energy

controled insects and diseases, etc. (Guangyong et al.

consumption and balance long-term productivity with2011; Mosher and Corscadden 2012), however

ecological sustainability (Mingl and Sauerborn 2006).

modern agriculture requires higher amounts of

Rice–duck farming, a form of organic agriculture, hasnonrenewable energy sources such as fossil fuels formany economic, environmental, and ecological benefits.

operating farm and irrigation machinery, producing

They have been recommended to apply in many Asian

chemical fertilizers, pesticides, and herbicides and using

countries, particularly Japan, China, Indonesia andelectrical inputs which may be produced by fuelPhilippine. This system creates an yield increasing

consumption in power plants. Besides, modern

because of integrated cultivation of rice planting and duck

traditional

agriculture.

Fortunately,49Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

breeding. It also saves farmer’s inputs of herbicides,

2.2 Data collection
The study was collected data for a two year period

insecticides, fungicides, and chemical fertilizers whichfrom 2014 to 2015 by gathering data from different

are replaced with duck manure and frequent movements

five rice planting farms regarding to variety andof ducks to control weeds and insects. Recent studies havecultivation method in two communes, Duy Tien

investigated high advantages of this system with respect toDistrict. The study took both conventional riceenvironmental andcultivation as well as rice-duck mutualism organic

ecological issues compared toconventional cultivation methods.

farming into consideration with the average area of
1ha.

Rice (Oryza sativa L.) is one of main agricultural

The survey volume was determined by the simple

products in Viet Nam contributed significantly to therandom sampling method (Yates et al 2008; Ghasemi

GDP. However, the paddy crops requires plenty of

Mobtaker et al 2010):

water and labor, it is believed to consume much energy.
The rice conventional cultivation method in Vietnam used(1)chemical fertilizer and organic matters increase the costfor rice product and effects long term on environment.

Where: n is the required sample size

Thus, efforts are immediately required not only tos is the standard deviation

improve rice production but also to decrease the costs by

t is the t value at a 95% confidence level
N is the number of holding in target population

solving environmental problems such as nitrated is the acceptable error (permissible error 5%)

leaching and eutrophication. Rice-duck multualism
organic farming has been widely applied in Vietnam,
especially in flood areas. This study aims to makecomparison of the energy use efficiency between
organic (rice –duck cultivation) and conventional riceproduction methods.

Material and Method
2.1 Site description
The current study was conducted in Duy Tien

Fig 1. Location of Duy Tien District, Ha Nam Province

District of Northern Ha Nam Province, the gateway to
the South of Hanoi. Red River is along the northeast

2.3 Data miningof the district (Fig.1). This area is located between
105053’26” and 106002’43” lat. N and 20032’37” and20032’37” long. E. The climate of the area is tropicalThe inputs considered for these two modes weremonsoon, and characterized by the annual averagemachinery, human labor, diesel fuel, chemical fertilizers,

rainfall from 1,800-2,000mm, distributed mostly inorganic fertilizers, pesticides, fungicides, and herbicides as

autumn (took account for nearly 80% of total rainfall).

biocides, water for irrigation, seed, rice bran, and duckling.

Duringthestudy

period,anuualprecipitation

The outputs considered were grain, straw, and duck as ameasured 1,660.6 mm in 2014 and 1,520 mm in 2015.
The annual average temperature is 23.2

to 24.6

with a monthly maximum ranging from 32-35

product. The input and output amounts of 1 ha utilized in,

two rice production systems are referenced in Table 1.

in

Human energy as an energy input was calculated

June and July and a minimum of 6-8
in November
and December. The main type of soil here is alluvium
soil.

by multiplying the number of man-hours (hha—1)
based on the estimated power rating of human labor(MJh—1) from Table 1. The energy used by machinery50

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

Table 1. Energy equivalent of inputs and output in two

was estimated as follows (Kitani et al. 1999):

different rice production systems

ME = E × G × T (2)

Input

Unit

Energywhere ME is the machinery energy (MJ), E is theequivalent

production energy of the machine (Table 1), G is the(MJunit-1)

mass of the machine (kg), and T is the economic life of

A. Inputs

the machine (years). Chemical fertilizer energy, diesel

1.

fuel, seed, biocides, organic fertilizers, water, rice bran

Machinery

h

62.70

References

Royan
et al.(2012),

and duckling in rice production can be calculated bymultiplying the quantity of the material used on the

2. Labor

farms by the energy equivalent of each material.

Male

h

1.96

Singet al.(1994,

Femaleh

1.54Singet al.(1994

3. Diesel

L

56.31

Alikhani (2013)

The energy output which included paddy rice,straw and duck can be separately estimated by

4. Chemical

multiplying yield of each output (kg ha-1) by the energy

fertilizer

equivalent (MJ kg-1)

Nitrogen(N)

The total input energy equivalent was the sum of

Phosphorus

the energy equivalence of each input (MJ). Similarly,(P2O5)

the total output energy equivalent can be calculated by

Potassium

adding up the energy equivalences of all outputs (MJ).

(K2O)

From the two measurements, the energy use efficiency,

Zinc (Zn)energy productivity, specific energy and net energy

5. Organic

–
kg

66.14

kg

12.44

kg

11.50

kg

8.40

ton

303.1

Kitani (1999)
Kitani (1999
Kitani (1999
Alikhani (2013)
RaiJadidi (2010)

were also calculated. (Hulsbergen et al. 2001; Yilmaz etfertilizer

al. 2005; Dermircar et al. 2006; Shahan et al. 2008).

6. Biocide–

Insecticidekg

Fungicidekg

7. Seedkg

14.70

Kitani(1999)

8. Rice bran

kg

12.55

Sayin et al.(2005)

9. Waterm3

1.02

Alikhani (2013)

10. Duckling

kg

14.10

William (2008)

kg

14.70

Alikhani (2013)

(3)
(4)
(5)
The total energy input was also classified into either

0
229.0
0
115.0
0

Kitani (1999)
Kitani (1999)

direct and indirect or renewable and nonrenewable forms.

B. Outputs

Direct energy (DE) included human labor and diesel fuel1. Paddy

energy used in the production process, while indirectriceenergy (IDE) consisted of machinery, seed, chemical

2. Straw

kg

12.50

Alikhani (2013)

fertilizer, biocide, organic fertilizer, rice bran, water, and3. Duck

kg

14.10

William (2008)

duckling and duck energy. In this study, Renewableenergy (RE) consisted of seed and human labor, organic

Duck farming is labor-intensive, thus the human labor for

fertilizer,

duck;

the rice-duck mutualism organic farming was higher thannonrenewable energy (NRE) included machinery, diesel

conventional rice cultivation system (320 h and 290 h.,

fuel, biocides, and chemical fertilizers.

respectively). Rice-duck organic farming requires less

Results and Discussions

energy input in machinery than the conventional rice

The inputs and outputs for the rice–duck and thecultivation, around 150 h ha-1 of rice-duck organic

conventional rice cultivation are shown in Table 2.

farming compared with 202.1 h ha-1 of conventional rice

rice

bran,

water,

duckling

and51

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

cultivation. Besides, only 2.4 tons of organic fertilizer was

farming and 42.87% for the conventional rice cultivation.

used in the rice-duck mutualism organic farming system

Meanwhile, the figure for direct energy in both systems

compared with about 8 tons required to apply in thewas sharply different, 53.54% for the rice-duck

traditional rice cultivation.

mutualism organic farming and 33.09% for the

The long-term adverse health and environmental effects

conventional rice cultivation system. The percentages ofof biocides such as insecticide, herbicide, and fungicide as

renewable and nonrenewable energies for the rice-duckwell as chemical fertilizers like Nitrogen (N), Phosphorus

mutualism organic farming were 31.80% and 67.33%,(P2O5) was be minimized. Because there is no chemical

respectively. These figures for the conventional rice

fertilizers or biocides needed to utilize in the rice-duck

cultivation were 8.49% and 67.47%, respectively. Thismutualism organic farming areas (table 2). Therefore, thefacts

system seems to be more beneficial to the environment.

nonrenewable energy was utilized for the conventional

The amount of diesel fuel utilized for conventional rice

rice cultivation, but the difference gap was closer for thecultivation was greater than the rice-duck mutualism

rice-duck mutualism organic farming.

show

that

a

much

higherpercentageoforganic farming, at approximately 654.5 and 600L,
respectively. Fuel consumption energy input in bothConclusion

systems was 52.67% for the rice-duck mutualism organic

The rice–duck organic farming, a form of organic

farming and 32.65% for the conventional rice cultivation.

agriculture, has many economic, environmental, andThe rice-duck organic farming used less energy

ecological benefits in Vietnam. According to the results

inputs than the conventional rice cultivation, but theof the current study, the ratio of renewable energy toenergy outputs of the rice-duck organic farming wasnonrenewable energy utilized in this system was greaterobtained more. The energy input required in thethan that in the conventional rice cultivation where therice-duck organic farming was significantly lower thanmain nonrenewable inputs were chemical fertilizers andthe conventional rice cultivation, at 64,146.5 MJ ha-1 andbiocides. The rice–duck mutualism organic can improve

112,893.5 MJ ha-1, respectively, but the total energy

the structure of paddy soils and suppress weeds using

output in the rice-duck organic farming was slightly

renewable energy resources. The results of this research

greater than that of the conventional rice cultivation, at

can provide theoretical and practical bases for further

about 134,801.2 MJ ha-1 and 124,488.3 MJ ha-1,

optimizing the cultivation method and increase therespectively.

economic benefits for farmers through the effective use ofenergy and ecosystem conservation.

Table 3 shows the energy consumption, productivity, andenergy gain of various processes in rice production. The

References

energy efficiency of the rice-duck organic farming was

AghaAlikhani M, Kazemi-Poshtmasari H, Habibzadeh F (2013)

doubled compared with the conventional rice cultivation,

Energy use pattern in rice production: a case study fromat 2.1% and 1.1%, respectively. The energy productivity

Mazandaran prov- ince, Iran. J Enconman 69:157–162.

values of the rice-duck mutualism organic farming wasestimated to be 0.15 kg MJ-1, while the figure for the

Guangyong L, Xiaoyan L, Cuihong J, Guohua L (2011)

conventional rice cultivation was only 0.08 kg MJ -1. The

Analysis on impact of facility agriculture on ecological
function of modern ag- riculture. Procedia Environ Sci

net energy values in the rice-duck mutualism organic

10:300–306.

farming 70,655 MJ ha-1, in contrast to the figure for theKibirige JS (1997) Population growth, poverty and health. Soc Sci

convention rice cultivation, which only 11,595 MJ ha-1

Med 45(2):247–259

was produced. The indirect energy was nearly equally

Kitani O (1999) CIGR Handbook of agricultural engineering.

used, at 45.6% for the rice-duck mutualism organic

52

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

Energy and biomass engineering, Vol. 5. St Joseph, MI: ASAE
Publication Kizilaslan H (2009) Input–output energy analysis ofcherries productionin Tokat Province of Turkey. Appl Energ 86:1354–1358.
Mingl MA, Sauerborn J (2006) Review of history and recent
develop- ment of organic farming worldwide. Agr Sci
China 5(3):169–178
Mosher JN, Corscadden KW (2012) Agriculture’s contribution
to the renewable energy sector: policy and economics—dothey add up? Renew Sust Energ Rev 16(6):4157–4164.
RaiJadidi M, Homayonifar M, Sobohisaboni M, Kerdmand V(2010) Study performance and energy efficiency in tomato
production. J Agr Econ Dev 24(3):363–370
Royan M, Khojastehpour M, Emadi B, Ghasemi Mobtaker H(2012) Investigation of energy inputs for peach production
using sensitivity analysis in Iran. Energy Convers Manage64(3):441–446
Sayin C, Mencet M, Ozkan B (2005) Assessing of energy
policies based on Turkish agriculture: current status andsome implications. Energy Policy 33:2361–2373.
Singh S, Singh S, Mittal JP, Pannu CJS, Bhangoo BS (1994)
Energy inputs and crop yield relationships for rice inPunjab. Energ 19(10):1061–1065.
Nguyen Viet Anh, ảnh hưởng của chế độ tưới tiết kiệm nướcđến phát thải khí methan tròn ruộng lứa, tạp chí tàinguyên nước, 2010
Dinh Thi Lan Phuong, Giải pháp tưới thích ứng với BĐKH ở ViệtNam, tạp chí tài nguyên nước, 2017.

53

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

Table 2. Amounts of used inputs and outputs and their energy equivalences in two rice production systems

Item

Rice–duck mutualism organic farming

Conventional rice cultivation

Quantity per unit

Energy equivalent

Percentage Quantity per unit

Energy equivalent

Percentage

area (ha)(MJ unit-1)(%)

area (ha)(MJ unit-1)(%)

1. Machinery (h) 150±7.40

9405±464

14.66

202.1±7.64

12,671.7±479

11.22

2. Human Labor

320±28.7

555.8± 63.4

0.87

290.1±6.17501.2±15.6

0.44Male (h)150±8.09294±15.9

0.46

130.0±5.07

254.8±100.23

Female (h)170±30.9

261.8±47.6

0.41

160±3.70

246.4±5.7

0.22

3. Diesel (L)

600±6.2

33,786±349

52.67

654.5±1.936,854.9±107

32.65

4. Chemical

0.00

0

0

900.0024,480±1,380.2

21.68

Nitrogen (N)

0.00

0

0

250±20.2

16,535±1,336

14.65

Phosphorus

0.00

0

0

500±2.1

6,220±26.1

5.51

0.00

0

0

150±1.83

1,725±21

1.53

0.00

0

0

0

0

0

727.4±278.9

1.13

8.00

2,424.8

2.15

A. Inputs(h)fertilizer (kg)(P2O5)
Potassium(K2O)
Zinc (Zn)

5. Organic fertilizer 2.40±0.92(ton)
6. Biocide (kg)

0.00

0

0

15.02±0.93

2162.9±244

1.92Insecticide

0.00

0

0

6.22±0.83

1,424.4±190

1.26Herbicide

0.00

0

0

4.90±0.27

416.5±230.37

Fungicide

0.00

0

0

2.80±0.27322±310.29

50.20±2.3

738±33.8

1.15

50.20±2.07

738±30.4

0.65

11,923±359

18.59

0

0

0

7. Seed (kg)8. Rice bran (kg) 950.00±28.6
3

9. Water (m )5500.00±8.4

5610±8.6

8.75

5800.00±18.4

5,916±18.8

5.24

10. Duckling (kg)60.00±4.40

846±62

1.32

0.00

0

0

64,146.5

100.0–

112,893.5

100

Total energy input –B. Outputs
1. Grain (kg)

6500.65±156.17

95,559.6±2,296

70.89

6300.2±146.2

92,612.9±2,149

74.39

2. Straw (kg)2575.12±124.5

2,189±1,556.3

23.88

2550.03±122.8

31,875.4±1,535

25.61

3. Duck (kg)500.19±14.9

5,702.7±210

5.23

0.00

0

0

134,801.2

100

8,850.23

124,488.3

100

Total energy output 9,575.96

54

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

Table 3.

Energy forms and indices in two rice production systems

Item

Unit

Rice-duck

Percentage

organic farming(%)

Conventional rice

Percentage

cultivation(%)

Energy use efficiency–

2.1±0.11–

1.1±0.1

Energy productivity(kgMJ-1)

0.15

–

0.08

–

–

Specific energy(MJkg-1)

6.70

–

12.76

–

–

Net energy(MJha-1)

70,655±2,379.9–

11,595±237–

Direct energy(MJha)

34,342±412.6

53.54

37,356.1±122.6

33.09

Indirect energy(MJha-1)

39,249±1,206

45.60

48,393.3±2,155.5

42.87

Renewable energy(MJha)

20,400±806

31.80

9,580±64.88.49Nonrenewable energy(MJha)

43,191±813

67.33

76,169.4±2,213

67.47

Total energy input(MJha)

64,146.5

100.00112,893.5

100.0055–

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 201756

Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

Deficit Irrigation of Soybean
The Effect of Deficit Irrigation on Root/Shoot ratio, Water Use Efficiency andYield Efficiency of Soybean
Shakil Uddin Ahmed1, Masateru Senge2, Kengo Ito3, and John Tawiah Adomako 4
1
Professor, University of Dhaka, Dhaka-1000, Bangladesh; 2Professor, Faculty of Applied
Biological Science, Gifu University，1-1 Yanagido, Gifu 501-1198, Japan; 3 Professor, Facultyof Applied Biological Science, Gifu University，1-1 Yanagido, Gifu 501-1198, Japan; 4Visiting
Researcer, Faculty of Applied Biological Science, Gifu University，1-1 Yanagido, Gifu 5011198, Japan.
SUMMARY
An experiment was conducted in a vinyl house at Gifu University, Japan, to investigate theeffects of water stress on root:shoot ratio and water use efficiency (WUE) at different growthstages, and its influence on yield efficiency (YE) of soybean. The treatment imposed was deficit
irrigation with five levels including D1 (0-20%), D2 (20-40%), D3 (40-60%), D4 (60-80%), andD5 (80-100%) water deficits of total available water (TAW). The treatments were arranged in arandomized complete block design with nine replications. Samplings were done at 49 DAS(flowering stage), 77 DAS (seed growth stage), and 140 DAS (maturity stage) during theexperiment. Soybean grain yield (Y, g/plant) significantly correlated to the crop waterrequirement (CWR, g/plant) as well as to the leaf area index (LAI, m2/m2) and total dry biomass(TDB, g/plant) at different growth stages in response to water deficit levels. These relationships
indicated the water stress decreased CWR which in turn caused the decrease in LAI and TDB anda subsequent decrease in grain yield. However, WUE and YE values increased with increasing
root:shoot ratio up to the D4 treatment and thereafter, decreased up to the D5 treatment inresponse to increasing water deficit levels. The study showed that, the most effective economic
water usage with the highest YE was at D4 (60-80 % of TAW) water deficit. It could produce 21%
lower yield per unit area, but could conserve 18% irrigated water to produce the same yieldcompared to the potential yield produced under full irrigation (D1).

Introduction
Soybean is economically important crop with widespread consumption, utilization in vegetable
oil and veterinary industries. Soybeans can be processed into Tempe, Tofu, and Soya, which areincluded in cuisines. Soybean is a traditionally nonirrigated (rain fed) crop that occupies quite
extensive areas in agro ecosystems. Drought is a worldwide problem, constraining global
production and quality of crop seriously, and recent global climate change has made thissituation more serious. The great challenge for the future will be the task of increasing foodproduction with less water, particularly in countries with limited water and land resources. In thecontext of improving water use efficiency, there is a growing interest in ''deficit irrigation''. At
present and more so in the future, irrigated agriculture will take place under water scarcity. To
cope with scarce supplies, deficit irrigation, defined as the application of water below full crop1
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Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

water requirements (evapotranspiration), is an important tool to achieve the goal of reducing
irrigation water use. According to James (1998), full irrigation is economically justified whenwater is readily available and irrigation cost is low. Shortage of available water is one of themost significant environmental stresses that cause yield reductions (Boyer, 1982).
Demand for evapotranspiration can be reduced either through agronomic measures or throughthe use of deficit-irrigation programs (Kirda et al. 1999). The main approach in deficit irrigation
practice is to increase crop water use efficiency by partially supplying the irrigation requirement
and allowing water stress to planned plant during one or more periods of the growing season
with the least impact on crop yield. Deficit irrigation management requires optimizing the timing
and degree of plant stress, within the restriction of available water.
Improvements in yield efficiency of crops through water use efficiency are essential under
the scenarios of water scarcity predicted by global climatic changes. Direct impacts of drought
stress to the physiological development of soybean depend on its water use efficiency (WUE)(Earl, 2002). In agriculture management involving soybean as a crop, WUE is an important
physiological characteristic related to the ability of plants to cope with water stress. According to
Passioura (1997), grain yield (Y) is a function of the amount of water transpired, WUE, andharvest index. Soybean, as a C3 plant, is less efficient in water-use due to highevapotranspiration and low photosynthetic rates.
Water stress disrupts the balance between roots and shoot ratio (Shangguan et al. 2004).
Water use efficiency also reduced by increasing root per shoot ratio. Benjamin and Nielsen(2006) reported that shoot dry weight of water stressed chickenpea reduced relative to root dry
weight. Numerous studies have shown that soil water stress has significant effects on plant
growth. Far fewer studies have focused on the root:shoot ratio response of plants, especiallysoybean crops, to water stress. Water stress in soybean has been shown to reduce growth ofabove-ground organs, leaf photosynthesis and leaf transpiration. However, studies are notavailable on the adaptation of soybean crop to water stress and its effects on root:shoot ratio forwater uptake and its relationship to water use efficiency (WUE) and yield efficiency (YE).
Therefore, the research was conducted with the objective to investigate the effects of water
stress on root:shoot ratio and water use efficiency at different growth stages and its relationshipto yield efficiency of soybean. This research can be used to determine water saving irrigation
schedules to ensure optimum production of soybean.
Material and Method
Area description
This research was conducted in a vinyl house (surrounding sides were open) located in theexperimental farm of Gifu University (35°27' N. & 136°44' E.), Japan. The average temperature
was 22.4℃ and the relative humidity was 67.5% during experiment duration. The soil was clay
loam in texture (0.40g/g sand, 0.27g/g silt and 0.33g/g clay) and classified as Inceptosl. The bulk
density was 1.07 (g/cm3). Soil water content at field capacity (34.7kPa) was 0.516 m3 /m3 andwilting point (185kPa) was 0.296 m3 /m3. Therefore, the total available water (TAW) was 0.220
m3 /m3.
2
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Treatments and experimental design
Five water deficit treatments namely; D1 (0-20%), D2 (20-40%), D3 (40-60%), D4 (60-80%) andD5 (80-100%) of total available water deficit (TAW) were arranged in a completely randomized
block design with nine replications. The water deficit level of D2 (20-40%), for example, meantthat the available water was maintained between 20% and 40% of TAW throughout the growing
season. When the maximum allowable depletion of available water came closer to 40% of TAW,
water was applied to restore the available water to the deficit level of 20% of TAW. The TAW is
defined as the water content between field capacity (FC) and permanent wilting point (PWP).
Plastic pots (10 liters volume and 23.8cm diameter) with no drainage holes were filled with 7
kg air-dried Inceptisol (clay loam in texture). Then five soybean seeds [Glycine max (L.) Merrill]
were sown in each pot. Prior to planting, uniform water was applied to all the pots to bring themto field capacity (FC) for uniform germination. The soil moisture for all pots was maintained atfield capacity (FC) until 14 days after sowing (DAS). After 14 DAS, the deficit irrigation
treatments were initiated. The irrigated period of soybean was 20 weeks from June 16 toNovember 3. The plants were thinned to one per pot at the 2- to 3- leaf stage. Three replicate
pots of each water deficit level were sampled at 49 DAS (flowering stage), 77 DAS (seed growthstage), and 140 DAS (maturity stage) during the experiment. Three plants per treatment wereused for final yield analyses.
Measurements
Agronomic variables evaluated in this research were crop water requirement (CWR, g/plant),oven dry (at 65°C for 96 h) weight of total biomass including roots (TDB, g/plant), root dry
weight (g/plant), shoot (leaves and stem) dry weight (g/plant) and air-dried grain yield ofsoybean (Y, g/plant). Leaf area index (LAI, m2/m2) were measured according to Fehr and Cavines(1977) using a portable leaf area meter (Model LI 3000A; LI-COR Inc. Lincoln, NE, USA) fromeach pot. Crop water requirement (CWR, g/pot) was calculated from the evapotranspiration
during the irrigated period of soybean according to Allen et al. (1998). Daily evapotranspiration(ET, mm/d) was measured by weighing the pot every day.
Result and Discussions
Crop water requirement (CWR) and water stress coefficients (Ks)
The crop water requirement (CWR, g/plant) of soybean at the different growth stages
significantly decreased with increasing water deficit level (Table 1). Similarly, leaf area index(LAI, m2/m2) also significantly decreased at the different growth stages with increasing water
deficit level. Figure 1 shows that CWR significantly correlated with LAI at different growthstage in response to the water deficit level. This result agrees with Van Wijk et al. (2005) who
demonstrated that LAI is a key variable, functionally related to canopy microclimate, waterinterception, radiation extinction, and water and carbon exchange. Setiyono et al. (2008) also
demonstrated that transpiration is directly controlled by LAI. In the present study, the highest
359Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

correlation was observed at seed growth stage (77 DAS) compared to the flowering and maturity
stages, because LAI reaches maximum at this time.
According to Allen et al. (1998), evapotranspiration under water stress condition is referred toas the adjustment evapotranspiration (ETcadj, mm/d) which can be calculated by the following
equation.
ETcadj=Ks ETc(1)where ETc (mm/d) is the crop evapotranspiration under standard condition, Ks is water stresscoefficient (no dimension).
The value of Ks is important for estimating ETcadj, and can be used for deficit irrigation
scheduling. Ks describe the effect of water stress on crop transpiration (Allen et al. 1998).
Assuming that the evapotranspiration at D1(0-20%) occurred under the ideal condition for plant
growth in which the soil water content is near the field capacity, the actual evapotranspiration(ETa) at D1 is crop evapotranspiration (ETc), which means the evapotranspiration of plant understandard conditions (Allen et al., 1998). Water stress coefficient (Ks) is calculated as the ratio
between the actual evapotranspiration (ETa) at each water deficit level and the crop
evapotrarspiration (ETc). The ratio of water depletion to the total available water in the root
zone, referred to as “p”, is an indicator of the water deficit level. For example, the average valueof “p” under the water management of D2 (25-50%) treatment is calculated as “p” =(0.20+0.40)/2=0.30.
The variation of Ks values of soybean is displayed in Table 1. Water deficit level had
significant effects on water stress coefficient (Ks). The variation of Ks values of soybean
depends on the growth stages and the water deficit level. Figure 2 shows that the Ks values
decreased linearly with the increase of water deficit level “p”. The fastest decline of Ks value wasat the seed growth stage (77 DAS) which indicates the most sensitive period to water deficit. Our
result agrees with Doorenboss and Kassam (1979) who stated that, water requirement is higher
during emergence, flowering and early yield formation than early (vegetative, after
establishment) and late growth periods (ripening).

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Table 1 The effect of water deficit level on crop water requirement (CWR), leaf area index (LAI),
root:shoot ratio, total dry biomass (TDB), water stress coefficient (Ks) and water use efficiency(WUE) of soybean under different growth stage
Growthstage(DAS)

Flowering
(49)

Water
deficit
level
(%)

CWR
(g/plant)

LAI(m2/m2)

①

②

Shoot
dry
weight(g/plant)
③

Root
dry
weight(g/plant)
④

D1

Root:
shoot
ratio
(g/g)
⑤=④/③

TDB
(g/plant)

Ks

WUE
(g/g)

⑥＝③+④

⑦

⑧=⑥/①

24183
5.8
48.93
12.70
0.259561.63
10.00255
a
a
a
a
a
a
a
a
D2
20220
5.6
40.70
12.07
0.296552.77
0.84
0.00261
b
b
b
b
a
b
b
a
D3
17754
4.8
36.50
11.37
0.311447.87
0.73
0.00270
c
c
c
c
a
c
c
a
D4
14080
4.5
29.47
9.60
0.325839.07
0.58
0.00277
d
d
d
d
a
d
d
a
D5
12867
3.7
25.30
5.97
0.236031.27
0.53
0.00243
e
e
e
e
b
e
e
b
Seed
D1
50475
6.7
87.87
16.87
0.19196104.731
0.00207
growth
a
a
a
a
a
a
a
a
(77)
D2
46270
6.5
81.60
16.57
0.20302
98.17
0.92
0.00212
b
b
b
a
a
a
b
a
D3
39039
5.9
71.00
14.97
0.2108085.97
0.77
0.00220
c
c
c
b
a
b
c
a
D4
31759
5.5
59.33
13.60
0.2292172.93
0.63
0.00230
d
d
d
c
a
c
d
a
D5
25608
4.5
41.37
7.10
0.1716448.47
0.51
0.00189
e
e
e
d
a
d
e
a
Maturity
D1
82130
6.2
117.1019.80
0.1691136.9010.00167
(140)
a
a
a
a
b
a
a
a
D2
74719
6.0
113.8319.53
0.1716133.370.91
0.00178
b
b
b
a
b
a
b
a
D3
64460
5.7
109.8319.50
0.1775129.330.78
0.00201
c
c
c
a
a
b
c
a
D4
53155
5.3
95.50
17.53
0.1836113.030.65
0.00213
d
d
d
b
a
c
d
a
D5
40205
3.9
67.50
11.80
0.174879.30
0.49
0.00197
e
e
e
c
b
d
e
a
Means followed by different small letters (a-e) in the same column in each growth stage under different water deficit levels
are significantly different according to Tukey’s multiple comparison test (p<0.05).

5
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Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

90000
49DAS

CWR (g/plant)

75000

R2 = 0.906*

77DAS
140DAS

60000

R2 = 0.9562**

45000
30000

R2 = 0.8881*

15000
0
0

1

2

3

4

5

6

7

8

LAI (m 2 /m 2 )Figure 1 Effects of water stress on the relationship between leaf area index (LAI)
and crop water requirement (CWR)

10-49 DAS
50-77 DAS

0.8

78-140 DAS

Ks

0.6
0.4
0.2
0
0

0.2

0.4

0.6

0.8

1

p

Figure 2 Effects of available water deficit (p) on water stress coefficient (Ks)
Total dry biomass (TDB) and water use efficiency (WUE)
The shoot dry weight and root dry weight as well as total dry biomass (TDB, g/plant) at eachgrowth stage significantly decreased with increasing water deficit level (Table 1). However, theroot:shoot ratio increased up to the D4 and thereafter, decreased to the D5 treatment withincreasing water deficit level (Table 1). Under water stress conditions, water can be easily lostby evaporation from the surface layer of soil. Therefore, soybean root profile is characterized by
662Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017a low amount of roots in the dry surface layer and a maximum root proliferation in the deeper
and wetter soil layer. On the other hand, shoot growth might be restricted due to the restriction ofcell division and enlargement under water stress conditions. Our results agree with Nicholas(1998) who stated that the root:shoot ratio increases under water-stress conditions to facilitate
water absorption. The root growth decline was greater in the top soil than deeper soil, because
water uptake per unit root length generally increased with depth in the soil.
Water deficit had significant effects on total dry matter accumulation (TDB) (Table 1). Water
deficit reduced final dry matter by an average of 42% (P<0.05) at D5 treatment compared to thefull irrigation (D1). The TDB at different growth stage significantly correlated with CWR under
the water deficit level (Figure 3). Our study indicates that the decrease in total dry biomass wasdue to the considerable reduction in plant growth and canopy structure caused by the water stressconditions. This phenomenon agrees with Hong-Bo Shao et al. (2008) who found that thebiomass of soybean plant was reduced by the water stress imposed.
Water use efficiency (WUE, g/g) is defined as the ratio of total dry biomass (TDB, g/plant) tothe crop water requirement (CWR, g/plant). The WUE value increased with the increase of water
deficit level, except water deficit level in D5 (Table 1). In addition, WUE showed significant
positive correlation at different growth stage with root:shoot ratio in response to increasing water
deficit level (Figure 4). In fact, when evaluated over the entire growing season, the stressed
plants have higher water use efficiencies than the well-watered plants. Our findings are inagreement with those of Burriro et al. (2002) who reported that WUE increased with the increaseof soil moisture stress.
160
R2 = 0.8813*

TDB (g/plant)120
R2 = 0.9599**
49DAS

80
R2 = 0.9736**

77DAS
140DAS

40

0
0

20000

40000

60000

80000

100000CWR (g/plant)

Figure 3 Effects of water stress on the relationship between total dry biomass(TDB) and crop water requirement (CWR).

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Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

0.0030R2 = 0.9577**
R2 = 0.9839**

WUE (g/g)

0.00250.002049DAS

0.001577DAS

R2 = 0.9176**

140DAS

0.00100.00050.0000
0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

Root:Shoot ratio (g/g)

Figure 4 Effects of water stress on the relationship between root:shoot ratio andwater use efficiency (WUE).
Grain yield and yield efficiency (YE)The grain yield declined with the increase of water deficit levels (Table 2). There was no
significant difference between the decreasing trend of D1 and D2 treatments but significantly
decreased from D2 to D5 treatment. It was found from the study that, the grain yield numericallylowered by 1, 11, 21 and 47 % in D2, D3 , D4 and D5 water deficit levels, respectively, as
compared to the D1 (full irrigation).
Table 2 Effects of water deficit level on grain yield (Y), crop water requirement (CWR), yieldefficiency (YE), and yield response factor (Ky)
Water
deficit(%)
D1(0-20)Y
CWR
YE
1-Ya/Ym
1-ETa/ETmKy(g/plant)(g/plant)
(g/g)
①
②
③＝①/②
④
⑤
⑥＝④/⑤
0.000216
17.7
82130
0
0
b
a
a
0.000234
D2(20-40)
17.5
74719
0.01
0.09
0.13
b
a
b
a
a
a
0.000245
D3(40-60)
15.8
64460
0.11
0.22
0.50
ab
b
c
b
b
b
0.000263
D4(60-80)
14.0
53155
0.21
0.35
0.59
a
c
d
c
c
c
0.000234
D5(80-100)
9.4
40205
0.47
0.51
0.92
b
d
e
d
d
d
Ya: actual yield, Ym: maximum yield, ETa: actual evapotranspiration, and ETm; maximum evapotranspiration
Means followed by different small letters (a-e) in the same column under different water deficit levels are
significantly different according to Tukey’s multiple comparison test (p<0.05).

The grain yield of soybean was strongly influenced by CWR (Figure 5), LAI (Figure 6), andTDB (Figure 7) at maturity stage (140 DAS). These results indicated that the reduction in CWR
as well as LAI and TDB by water stress caused the decrease of soil water uptake and864Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017consequently the decrease of soybean grain yield through reduction in photosynthesis. Passioura(1997) found the same phenomenon that grain yield is a function of the amount of
evapotranspiration.
20
y = 0.0002x + 2.5633
R2 = 0.9248**

Y (g/plant)

16
12
8
4
0
0

15000

30000

45000

60000

75000

90000

CWR (g/plant)

Figure 5 Effects of water stress on the relationship between crop waterrequirement (CWR) and grain yield (Y).

20
y = 3.7435x - 5.5
R2 = 0.9907**

Y (g/plant)

16
12
8
4
0
0

1

2

3

4
2

5

6

7

2

LAI (m /m )Figure 6 Effects of water stress on the relationship between leaf area index (LAI)
and grain yield (Y).

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Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 201720
y = 0.1325x - 0.6897
R2 = 0.983**

Y (g/plant)

16
12
8
4
0
0

20

40

60

80

100

120

140

160

TDB (g/plant)

Figure 7 Effects of water stress on the relationship between biomass (TDB) and grain yield(Y).
Yield efficiency (YE, g/g), the ratio of grain yield (Y, g/plant) to crop water requirement(CWR, g/plant) is a term used to assess how efficiently a crop uses water. Using less water toproduce more grain yield is important in saving water. The YE value increased with the increaseof water deficit level from D1 to D4 and thereafter decreased up to the D5 treatment (Table 2).
The significant positive relationship between YE and root: shoot ratio at maturity stage (140
DAS) showed that the YE increased with the increase of root:shoot ratio in response to increasingwater deficit levels up to the D4 treatment and thereafter decreased to the D5 treatment inresponse to increasing water deficit levels (Figure 8). Our study indicates that, the soybean crop
utilize the least irrigation water to produce more grain yield at D4 water deficit level. Therefore,
the highest YE were recorded at D4 water deficit level compared to the full irrigation (D1).
0.00028

YE (g/g)

0.00026

y = 0.003x - 0.0003
R2 = 0.9379**

0.000240.000220.00020
0.15

0.16

0.17

0.18

0.19

Root:Shoot ratio (g/g)

Figure 8 Effects of water stress on the relationship between root:shoot ratio andyield efficiency (YE).
1066Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

Yield response factor (Ky)The effect of water stress on yield is quantified by relating the relative yield decrease to therelative evapotranspiration deficit through an empirically derived yield response factor (Ky)
(Doorenboss and Kassam, 1979).
YET(2)
1  a  K y  (1  a )Ym
ETm
where 1-Ya/Ym: relative yield decrease, Ya: actual yield, Ym: maximum yield (under no stresscondition), 1-ETa/ETm: relative evapotranspiration decrease, Ky: yield response factor, ETa:actual evapotranspiration, and ETm: maximum evapotranspiration
Under conditions of limited water distributed equally over the total growing season, involving
crops with different Ky values, the crop with higher Ky value will suffer a greater yield loss thanthe crop with a lower Ky value (Moutonnet, 2000). According to a report by Doorenboss and Kassam(1979), the Ky of soybean under water deficit for the whole growing period was found to be 0.85.

Table 2 shows the values of the yield response factor (Ky) calculated using equation (2). The Ky
values obtained for the D2, D3, D4 and D5 treatments were determined throughout the growing
period were 0.13, 0.50, 0.59 and 0.92, respectively; with an average value of 0.53.
The relationship between relative yield decrease (1-Ya/Ym) and relative evapotranspiration
deficit (1-ETa/ETm) is shown in Figure 9. It shows that, the relation between the relative yield
loss (1-Ya /Ym) and relative water deficit (1-ETa/ETm) for water deficits lower than 60-80% of
TAW is almost linear with a mean Ky value of 0.41. These results agree with the experiment by
Doorenboss and Kassam (1979) who showed that the relationship between relative yield (Ya/Ym)
and relative evapotranspiration (ETa/ETm) was linear and valid for water deficit of up to about 50% or 1- ETa/ETm=0.5.
1-ET a /ET m
0.6

0.5

0.4

0.3

0.2

0.1

0
0

y = 0.7674x
R2 = 0.889**

0.2
0.3
0.4

Ky=0.53

0.5

Figure 9 Relationship between relative yield decreased (1-Ya/Ym) and relative
evapotranspiration deficit (1- ETa/ETm) in Inceptisol.

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1-Ya/Ym

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Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

Optimum deficit irrigation
The optimum yield of soybean with the highest values of YE was attained by the deficit irrigation
which maintained the available water deficit at 60-80% of TAW (D4) with water stress coefficient(Ks) of 0.65 and yield response factor (Ky) of 0.59. The value of YE at water deficit level D4 was
1.5 times as much as under the full irrigation (D1). It was also seen that the 60-80% (D4) deficit
irrigation reduced 21% of the grain yield per unit area, and could conserve 18% of irrigationwater to produce the same grain yield compared to full irrigation (D1).
Conclusion
The most unique result of our study is that we established a strong positive correlation among theroot:shoot ratio, water use efficiency (WUE) and yield efficiency (YE) of soybean under deficit
irrigation management. Our present study suggests that the yield efficiency increased with theincrease of water use efficiency as well as the increase of root:shoot ratio in response toincreasing water deficit levels. The study showed that, the most effective economic water usage
with the highest YE was at D4 (60-80 % of TAW) water deficit. It could produce 21% lower yield
per unit area, but could conserve 18% irrigated water to produce the same yield compared to thepotential yield produced under full irrigation (D1).
Acknowledgement
The authors are grateful for the financial support of the University of Dhaka, Bangladesh andsupported in part by The United Graduate School of Agricultural Science, Gifu University,
Japan. We thank the work of many people for data collection and processing.
References
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Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 20179) James, L. G., 1988: Principle of farm irrigation system designs, Wiley, New York, pp.140.
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Proceedings of the 5th International Workshop on Recent Progress in Agriculture and Water Management in Asia, 2017

IC-GU12 (International Consortium of Universities
in the South East and South Asian Region for theDoctoral Education on the Agricultural Science andBiotechnology) was established in 2012. Currently
in 2017, 18 Universities and Institutes from 7
countries including Gifu University, the facilitatorof the consortium, have been members of IC-GU12.
ISBN978-4-909365-01-970