Improving the water productivity of paddy rice (Oryza sativa L.) cultivation through water saving irrigation treatments

doi:10.4236/as.2011.24066

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Vol.2, No.4, 511-517 (2011)

doi:10.4236/as.2011.24066

Agricultural Sciences

Improving the water productivity of paddy rice (Oryza

sativa L.) cultivation through water saving irrigation

treatments

Joko Sujono1*, Naoki Matsuo2, Kazuaki Hiramatsu3, Toshihiro Mochizuki3

1Department of Civil and Environmental Engineering, Faculty of Engineering, Gadjah Mada University, Yogyakarta, Indonesia;

*Corresponding Author: [email protected]

2Lowland Crop Rotation Research Team, National Agricultural Research Center for Kyushu Okinawa Region, Chikugo, Japan;

3Department of Agro-Environmetal Sciences, Faculty of Agriculture, Kyushu University, Fukuoka, Japan.

Received 11 August 2011; revised 10 October 2011; accepted 27 October 2011.

ABSTRACT

Rice grows well under certain condition and

environment including soil, water and nutrients.

Some researches have shown that traditional

method with continues flooding need tremen-

deous amount of water for rice cultivation and

gives low water productivity. To increase the

water productivity, number of water saving iriga-

tion techniques have been studied and applied.

Study on effect of number of water irrigation

treatments on water productivity of rice was

carried out. Eight irrigation treatments were

conducted for growing rice in pot experiment i.e.

shallow intermittent irrigation (SII), alternate

wetting and drying (AWD1, AWD2, AWD3 and

AWD4), shallow water depth with wetting and

drying (SWD1 and SWD2), and semi-dry cultiva-

tion (SDC). The performance of those treat-

ments in terms of agronomic and water pa-

rameters was compared to the shallow inter-

mittent irrigation as a control method. The study

reveals that the shallow intermittent irrigation

needs the highest amount of water compare with

other treatments. The lowest amount of water

was achieved under the semi-dry cultivation. It

could save water up to 18.4% compare to the

control trea tment. By usin g the al ternat e wetting

and drying and the shallow water depth with

wetting and drying treatments, irrigated water

can be reduced up to 13.1% and 5.4%, respec-

tively. The hi gh est g rain was o btained by alternate

wetting and drying (AWD4) and the semi-dry

cultivation yielded the smalest grain . On average

the alternate wetting and drying and shallow

water depth with wetting and drying increased

the grain yield by 22.9% and 17.9%, whereas the

semi-dry cultivation reduced the y i eld up to 14%

compare to the shallow water depth treatment.

The alternate wetting and drying treatments

have significantly improved the water produc-

tivity by 41.6% , shallow water d epth with wetting

and drying increased by 24.2% relative to the

shallow intermittent irrigation treatment, whereas

the most saving water treatment i.e. the semi-

dry cultivation performed quite similar with the

shallow water depth treatment, as a result of low

grain yields under the treatment.

Keyw ords: Pot Experiments; Water Management;

Wetting and D rying

1. INTRODUCTION

Rice is important crop for billian people. In 2008, the

rice consumption in Asia reached 400 million ton, around

90% of the world rice consumption [1]. For producing

rice, a tremendous amount of water is used for the rice

irrigation under the traditional irrigation technique called

as a continuous deep flooding irrigation technique. In

this technique, the paddy fields are inundated all the time

starting from transplanting until nearly harvesting (e.g.

[2]) at certain water depth that varies from 50 mm to 100

mm. Almost 80% of water resources availability is used

for irrigation purposes.

Currently, the traditional irrigation technique is get-

ting difficult to be applied due to facing number of

problems. The most obvious problem is decreasing trend

in the water resources availability especially during dry

season. On the other hand, the water demands for do-

mestic and industrial water supply are increasing. As a

result, the water availability for agriculture purposes is

decreasing and conflicting among the water user and

among farmers can not be avoided. Moreover, the tradi-

J. Sujono et al. / Agricultural Sciences 2 (2011) 511-517

512

tional irrigation technique has also been reported only

yields a low of rice or low water productivity (e.g. [3]).

There is a major challenge for paddy rice cultivators

to increase the water productivity. To grow rice with

much less water is necessary and possible [4]. Research

has been conducted to increase the water productivity for

growing rice [2,3,5-9]. The formal research on water

saving irrigation (WSI) treatments for paddy rice in

China was started around 1985. The impetus came from

different aspects such as shortages of food and electricity

as well as water demand for industrial, domestic in-

creased sharply. The research on improvement of water

management for paddy rice was given priority for fund-

ing from the Government [2]. A number of WSI treat-

ments have been studied. Among the available treat-

ments include the system of rice intensification (SRI),

alternate wetting and drying (AWD), shallow water depth

with wetting and drying (SWD), and semi-dry cultiva-

tion (SDC) as the following.

1.1. System of Rice Intensification

System of rice intensification (SRI) is an innovative

paddy cultivation method attaining high paddy yields

with lower resource of input both water and fertilizer or

cost saving. SRI was developed initially in the 1980s in

Madagascar by Henri de Laulanie, a French Jesuit who

spent more than three decades in Madagascar trying to

devise better rice production method (e.g. [6]). The main

feature of SRI regarding to water treatment is keeping

the soil both moist and aerated so that roots have access

to both water and oxygen. Great results of SRI practice

have been reported in number of countries [6,10-12].

Uphoff and Randriamiharisoa [13] reported that double

even triple yields over those of traditional rice culture

were obtained by SRI in Madagascar. However, criti-

cisms of these reports on SRI were made by some re-

searchers such as [14-16] for the extraordinary yields,

effectiveness of SRI practices and experimental proce-

dures. Despite of the skeptics present of SRI, Horie et al.

[17] explained that basic elements of SRI have proven

potential to increase rice yield. Thus, if the elements of

SRI are satisfied, SRI could be a high-yielding rice sys-

tem.

1.2. Shallow Water Depth with Wetting and

Drying

The feature of shallow water depth with wetting and

drying (SWD) is comprehensive application of shallow

water depth. Shallow water depth is equals to 10 - 40

mm water depth on the surface of soil. The SWD has

been spread widely in the southern provinces of China

since 1980s. The standard water control adopted in the

region is in the range of 60% SMC (saturated moisture

content) to 40 mm. However, the extra limit levels up to

70 mm are set up for storing more rainfall and drainage

occurs when the water level goes beyond the limit (e.g.

[3,18]).

1.3. Alternate Wetting and Drying

The alternate wetting and drying (AWD) irrigation

technique by 2002 has been adopted on 40% of the rice

growing areas in China. However many scientific issues

remain to be addressed and the application of the AWD

techniques in some regions is still very difficult because

of both biophysical and socio-economic problems. Ex-

perience shows that demonstrations and training are

needed to encourage farmer for applying the AWD [3].

The main feature of field water control under AWD is

that paddy fields is intermittently submerged and dried.

With the AWD treatment, there is no ponded water layer

in paddy field for most of the season. It implies that

fields are not kept continuously flooded but are allowed

to dry intermittently beginning 30 days after transplanting

of the crop. In the AWD the paddy field is submerged for

3 - 5 days with the water depth equal to about 30 mm

and then allowed to dry naturally up to 70% SMC.

Standard of field water control is between 70% SMC as

the lower limit and the upper limit is set up to 30 mm [3].

This practice allows paddy fields to reach a relatively

dry condition prior to receipt of further water and store

more water after rainfall. As a result, the utilization of

rainfall is optimum and the irrigation water requirement

reduced greatly. As this practice reduces irrigation water

use so the water productivity is increased greatly. The

AWD practice increases the water productivity on-farm

level remarkable up to 1.52 kg/m3 of water compare with

the traditional one i.e. 1.04 kg/m3 of water on average in

the four provinces in China [3].

1.4. Semi-Dry Cultivation

There is a great difference of field water control be-

tween semi-dry cultivation (SDC) and SWD as well as

AWD. For SDC, the water depth is maintained only in

the revival of green to the middle stage of tillering, and

there is no water depth on paddy field in the other stages

in entire growing season. The standard of field water

control is between 70% SMC as lower limit and the up-

per limit is 0 mm, except in the beginning stages up to

30 mm. Comparing between SWD and AWD, SDC is the

most high water efficiency. The water productivity could

reach 70% higher than traditional continuous flooding

technique [3].

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2. MATERIAL AND METHODS

2.1. Experimental Site

The experiments were conducted at Kyushu University

Experimental Farm, Fukuoka, Japan (33˚37'N, 130˚27'E)

from mid August until beginning of November 2006

using pots with 15.6 cm diameter and 20 cm height.

Each pot weight is measured using an available scale.

Water was added to make a puddle soil. Scale was then

used to measure the added water weight. The soil mois-

ture suction of the soil was simply measured by using

Daiki tensiometer (DIK-3162 pressure gauge type).

Rice variety used for the experiment was Nipponbare.

The SRI method for transplanting was adopted i.e. young

seedling of 9 days after seeding and single seedling for

each pot was applied. Fertilizers used in the experiments

consists of 0.24 g/pot of N, 0.24 g/pot of P and 0.24

g/pot of K. One third of N and full doses of P and K

fertilizers were applied at 7 days after transplanting

(DAT). One third of N fertilizer was applied at growing

stage (25 DAT) and the remaining of N fertilizer used as

dressing was given at the panicle initiation stage i.e. at

40 DAT.

In the experiment, the number of tillers was counted

for 10, 20, 30, 40, 50, 60 and 70 DAT. Based on the till-

ers, the effect of water irrigation treatments was ana-

lyzed by comparing with the tillers number resulted un-

der shallow intermittent irrigation (SII) as a paddy con-

trol. The SII is chosen due to less water needed compare

to continuous flooding (traditional method). An example

of SII that has getting much attention is SRI practice.

The maximum productive tillers among the treatments

are the most potential treatment to yield the highest

spikelets or grain results, whereas water irrigation used

and the resulted grain affect to the water productivity.

2.2. Water Saving Irrigation Treatments

Eight water irrigation treatments were tested in the

study. Each treatment consists of three pot replicates.

The amount of irrigated water and when it should be

irrigated vary among the treatments and depend on eva-

potranspiration rate, soil moisture condition and the wa-

ter irrigation treatment used. For this purpose, daily

measurement of the pot weight was carried out. The

main features of the water irrigation treatments are de-

scribed as the following.

2.2.1. Shallow Intermittent Irrigation (SII)

In this treatment, shallow intermittent irrigation (SII)

[19] was applied where the maximum water depth was

set up at 20 mm and then it dries naturally. The irrigated

water was added when the depth reaches 0 mm (satu-

rated condition) or up to small cracks emerging (soil

moisture suction up to –10 kPa). This kind of water

treatment was applied for entire growing period from

transplanting up to ripening. An example of SII that is

normally applied in paddy rice cultivation is the SRI.

2.2.2. Alternate Wetting and Dry i ng (AWD)

The feature of water management for AWD is that

paddy pot is intermittently submerged and drying. The

maximum water depth was set up to the maximum level

at 20 mm and the minimum is 70% SMC (saturated

moisture content) or when the soil moisture suction

reaches −70 kPa. In this study, four different AWDs were

designed based on the starting point of no water depth

i.e.: AWD-1, alternate wetting and drying begin at 20

DAT; AWD-2, alternate wetting and drying begin at 30

DAT; AWD-3, alternate wetting and drying begin at 40

DAT, and AWD-4, alternate wetting and drying begin at

50 DAT.

2.2.3. Combining Shallow Water Depth with

Wet ti ng a nd Drying (S WD)

In the SWD the maximum water depth was set up to

20 mm while the minimum was at 70% SMC. In this

study two types of SWD were used i.e. SWD-1 for water

management where the drying begins at the middle stage

of tillering (in this study at 20 DAT) and SWD-2 when

the drying begins at the late stage of tillering (40 DAT).

Shallow water depth (maximum is 20 mm and minimum

is 0 mm water depth) were applied up to tillering, during

elongating and flowering stage, whereas wetting and

drying treatments were applied continuously from milk

ripening until ripening.

2.2.4. Semi-Dry of Cultivation (SDC)

There is a great difference of water irrigation treat-

ment between the SDC and the above mentioned. For the

SDC, shallow water depth is only maintained up to

tillering stage. The maximum water depth is 20 mm.

There is no water depth in the other stages in entire

growing season. In these stages, the maximum water

depth is 0 mm and the minimum is 70 SMC. The SDC

water irrigation treatment was started where no water

depth begins at the middle (20 DAT) stage of tillering.

3. RESULTS AND DIS CUS SION

3.1. Agronomic Parameters

Average tillers number under different water man-

agement treatments are given at Figure 1. The figure

clearly shown that up to 40 DAT there is no significant

difference among the treatments, however, starting at 45

DAT, the SII method gives more tillers than others. Un-

J. Sujono et al. / Agricultural Sciences 2 (2011) 511-517

514

der the AWDs, however, the number spikelets are sli-

ghtly better than others. The differences are not signifi-

cantly different at 0.05 probability level according to

Duncan’s multiple comparison test (Table 1). Better

performance of the AWDs is probably due to the com-

bined effect of alternating and drying processes that cre-

ating aeration soil more frequently than other treatments

and young transplanted seedling. Wetting and drying

improves the root system environment, so that the root

system has enough oxygen and water during tiller de-

velopment.

given during paddy rice cultivation started from trans-

planting up to ripening stage excluding water needed for

land preparation. The irrigated water is purely for rice

growing since there is no either seepage or percolation

from the pot experiments. The irrigated water require-

ment varies depending on water irrigation treatments as

presented in Table 2. Amount of irrigated water and wa-

ter saving compared to paddy control (SII) are also given

in Table 2.

10 25 40 55 70

Tillers number

Days after transplanting

SII AWD-1

AWD-2 AWD-3

AWD-4 SWD-1

SWD-2 SDC

According to Horie et al. [17], transplanting young

seedling has advantages than aged ones (traditional

method). The advantages lie in higher tolerance to trans-

planting stresses in younger seedling than aged ones.

However, not all these tillers develop to maturity (pro-

ductive tillers), some degenerate to become dormant when

young and some die later, depending on environmental

and nutritional conditions [17] as shown in Table 1.

3.2. Water Parameters

Water management embraces the control of water for

optimum rice yield and the best use of a limited supply

of water. Water required to produce optimum yield i.e.

irrigated water must satisfy the evapotranspiration needs

of the paddy rice and losses through percolation and see-

page. In this study, irrigated water is the amount of water

Figure 1. Effect of water treatments on tillers number during

vegetative growth.

Table 1. Water saving for different water saving irrigation treatments.

Water saving relative to control

WSI treatment Irrigated water

(mm) mm %

SII (control) 861 0 0

AWD-1 711 150 17.4

AWD-2 736 124 14.4

AWD-3 781 79 9.2

AWD-4 762 98 11.4

SWD-1 783 78 9.1

SWD-2 846 14 1.7

SDC 703 158 18.4

Table 2. Number of tillers and spikelets under different water irrigation treatments.

Number of tillers Spikelets

Water treatment 45 DAT Productive Total Per panicle

SII (control) 25.0a 16.7ab 1204ab 72.3ab

AWD-1 23.7ab 16.0b 1098

b 68.7bc

AWD-2 24.0ab 16.7ab 1182ab 71.0ac

AWD-3 23.0ab 16.3ab 1223ab 75.1a

AWD-4 22.0b 17.3ab 1303a 75.6a

SWD-1 22.0b 17.7ab 1163ab 65.9c

SWD-2 23.0ab 19.0a 1329a 70.2ac

SDC 22.7ab 18.0ab 1190ab 66.1c

Note: In a column, means followed by a different letter are significantly different at the 0.05 probability level according to Duncan’s multiple comparison test.

Openly accessible at

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The table shows clearly that AWD, SWD and SDC

treatments reduce the amount of water needed for paddy

rice cultivation compared to the SII as a control treat-

ment. The irrigated water reduction varies from 1.7% to

17.4%. In terms of irrigated water, the SDC is the most

promising method for water saving treatment, since un-

der SDC there is no standing water in the paddy field

and most of the time the soil is below saturated condition.

In addition for reducing irrigated water, the irrigation

treatment under SDC offers longer irrigation time inter-

val. That is more appropriate in practice compared with

the SII (for instance SRI), since to maintain the soil un-

der saturated condition as in the SII treatment is not an

easy task in real paddy fields. Longer irrigation interval

is important factor for irrigation water management es-

pecially for large area, rotation irrigation delivery system

due to limited water.

3.3. Water Productivity

The water productivity is defined as the amount of

filled spikelets or grain produced per unit quantity of

water. The water productivity is obtained by dividing the

total grain produced in each pot (g grain) by the total

amount of water used (kg–1 water). As total irrigated wa-

ter used and the yield vary among water irrigation treat-

ments, their water productivity will have different values

as shown in Table 3.

Table 3 shows that the AWDs produced more grain

yield than other treatments. The increasing grain yield

relative to the SII could reach 42% under AWD-4. On

average the AWD and SWD increased the grain yield by

22.9% and 17.9%, whereas the SDC reduced the yield

up to 14% compare to the SII treatment.

Due to reducing supply of water using intermittent ir-

rigation especially in AWDs (Table 2) and relatively

higher grain yield compare with other treatments (Table

3), the water productivity under AWDs treatments were

higher than others. Irrespective to irrigated water and

consumptive water use, the water productivity with

AWD-1, AWD-2 and AWD-4 increase by 44.8%, 39.6%

and 60.2% compared to SII treatments, respectively. On

average AWDs treatments have significantly improved

the water productivity by 41.6%, SWDs increase by

24.2% relative to the SII treatments. On the other hand,

the SDC performs quite similar with the SII treatments,

since the grain yields under SDC treatment was less than

the SII.

Table 3 shows that all the treatments give very low

water productivity compare to other study results. For

instance, Chapagain and Yamaji [9] based on experi-

mental research conducted in Japan reported that com-

binations of practices in the intermittent irrigation plots

yield 1.74 g grain/kg water with SRI management and

AWD as compared to 1.23 g grain/kg water from nor-

mal planting methods with ordinary water management.

The low yield caused by cold damage is probably oc-

curred in the experiment. The damage affects to the rice

growing especially during flowering and grain filling

stages, since in the experiment the flowering started at

the mid of October that is to late for paddy rice cultiva-

tion in Japan. As a result, the unfilled spikelet became

very high for all the treatments, it reached 60% to 75%

of the total spikelet that is very high compare to the

normal condition i.e. less than 20%.

3.4. Selection of the M ost Appropriate Water

Saving Irrigation Treatments

The most appropriate water saving irrigation treatment

of rice cultivation will depend on a number of factors

including natural resources condition (soil, topography,

climate) and socio-culture (farmer condition). Number of

criteria could be used for selecting the most approprite

water saving irigation treatment including grain yield,

amount of irrigated water needed, water availability and

accesbility, water productivity and practicality.

Table 3. Yield and water productivity for different water irrigation treatments.

Yield Water productivity

Treatment

(g/pot) % difference

Water

(g) (g grain/kg water) % difference

SII (control) 8.41 0.0 16879 0.50 0.0

AWD-1 10.05 19.5 13940 0.72 44.8

AWD-2 10.04 19.4 14445 0.70 39.6

AWD-3 9.30 10.7 15324 0.61 21.9

AWD-4 11.93 41.9 14950 0.80 60.2

SWD-1 8.88 5.6 15352 0.58 16.1

SWD-2 10.94 30.2 16597 0.66 32.4

SDC 7.21 –14.2 13781 0.52 5.0

J. Sujono et al. / Agricultural Sciences 2 (2011) 511-517

516

Grain yield is not the only factor that attract the

farmers to apply the current the sugested method. Even

though the SII management practices yields much higher

grain than the traditional (continuous flooding) as re-

ported by many researchers [6,12,20], it takes time for

farmers to apply the SRI management practice that

mainly consist of using young seedling, one seddling per

hill, soil moist condition, wider spacing. Even at the

some places, the farmers do not want to try it due to they

think it is labour intensive (e.g. [21,22]), difficult to

maintain especially weeding the weed that grow fastly

due to there is no ponding water and keeping the soil at

moist condition rather than flooded (e.g. [22]).

In terms of maintaining the water in the paddy field, it

is likely that the AWD could be accepted by the farmers

not only due to yield higher grain and water productivity

that others water saving irrigation (see Tabl e 3) but also

more reliable in practice. The irrigation water interval is

much longer than SRI current practice, it is appropriate

for paddy field that used rotation irrigation system due to

limited water supply and the AWD is easier for farmers

to use than aerobic rice systems like the SDC (e.g. [23]).

The use of combination between the SRI management

practice and AWD for paddy rice cultivation is also

supported by others [9,20,22]. Uphoff [20] mentioned

that the SRI water management practices currently rec-

ommended may still be suboptimal for many conditions,

with more water reduction possible. Based on the ex-

periment combining between the SRI current manage-

ment practice with AWD increased water productivity

significantly than the normal method (e.g. [9,22]).

4. CONCLUSIONS

The experiment revealed that the amount of irrigated

water for paddy rice cultivation, grain yield and water

productivity are highly depends on the water irrigation

treatment used. A combination between the SII current

management practice and other water irrigation treat-

ments could increase the water productivity by reducing

the water irrigated used and increasing the grain yield.

Among the water irrigation treatment tested together

with the SII management practice, the AWD is the most

promising one followed by SWD, the SII current man-

agement practice and the SDC due to the following:

1) The AWD could reduce the irrigated water up to

13.1% compared with the SII method, whereas the

SWD and SDC reduced the water up to 5.4 and

18.4, respectively.

2) On average the AWDs and SWDs increased the

grain yield by 22.9% and 17.9%, whereas the SDC

reduced the yield up to 14% compare to the SII

treatment.

3) The AWDs treatments have significantly improved

the water productivity by 41.6%, the SWDs in-

crease by 24.2% relative to the SII treatments. On

the other hand, the SDC performs quite similar

with the SII treatments, since the grain yields un-

der SDC treatment was less than the SII.

5. ACKNOWLEDGEMENTS

The authors thank to the Hitachi Schollarship Foundation for the

financial support to conduct the experiment in Kyushu University

Fukuoka Japan. The experiment was conducted at the Kyushu

University Experimental farm.

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