AWD Technology

7/30/2019 AWD Technology

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Alternate Wetting and Drying Irrigation (AWD): atechnology for water saving in rice production

To Phuc TuongCrop and Environmental Sciences Division

International Rice Research InstituteLos Banos, Philippines

[ Paper presented at the Crop Cutting Ceremony, BADC Farm, Modhupur, Tangail,

May 14, 2007 ]


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In Asia, about 40% of all fresh water diverted is for riceirrigation

How Much Water do People Use?

Liters of Water

Daily Drinking Water 2 5 Liters of Water

Daily Household Use 20 500 Liters of Water

1kg of Rice 3,000 5000 Liters of water input to the field

Pressure to produce more food (rice) is getting greaterbecause of ever increasing population

But also:More people want more industry more drinking water more cities more swimming

pools more.

=> Water is getting scarce and expensive

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Bangladesh:

Irrigation of Boro riceentirely depends on

GW and Tubewells

Farmers pay 30% ofrice output forirrigation

Gasoline cost >10,000Tk/ha foreigncurrency

Water savings = Cost savings and reducing energy crisis

Field water balance lowland rice

I + R = (E + T) + (S+P) + S

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Water requirements in lowland rice

Daily

mm d-1

Season (100 d)

mm

Land preparation 175-750

Evapotranspiration

-wet season- dry season

4-5

6-7

400-500

600-700

Seepage & percolation

-heavy clays-loamy/sandy soils 1-525-30 100-5002500-3000

(30% E, 70% T)

Total season : 675-4450 mmTypical value : 1500 mm

Reducing outflows: AWD

60

50

Fieldwaterdepth

40

30

20

10

00 10 20 30 90 10040 50 60 70 80 110

Days after Transplanting

Early

tillerin

PI to flowering Grain MaturitTransp. Latetillerinrecover

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Effect of less water (AWDn)

0

2

4

6

8

0 500 1000 1500 2000 2500 3000

Yield (t ha-1

)

Water input (mm)

Safe AWD concept and implementation

Multi-location field exps (Phil., India, China) On-farm, multi-stakeholder pilot sites Socio-economic evaluation at pilot sites

Safe AWD => reduced water input 15-30% without yield loss

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- 20 kPa at 15 cm

Safe AWD concept and implementation

Simple key messages for farmers

Simple tool for farmers

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A practical indicator to irrigate

- 20 kPa at 15 cm ~ water depth 15 cm

Safe AWD = Irrigate when water depth ~ 15 cm

Field water tube - installation

Push tube by

hand vertically

Push tube by

hand vertically

Drive cylinder

using mallet

Drive cylinder

using mallet

Check clearance

from soil surface

Check clearance

from soil surface

Appearance of

installed PW tube

Appearance of

installed PW tube

Remove soil

inside the tube

Remove soil

inside the tube

Check and level the

Top of the tube

Check and level the

Top of the tube

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Safe AWD practice

Start AWD 10 DATOr 20 DAS

2. Irrigate when water is 15-20 cm deep (simple tool !!)

3. Keep 5-cm flooded at flowering

Main idea to convey:

Water is there even when you cant see it Create confidence by farmers Farmers then to experiment with threshold value No recipe for soil type, hydrology, variety, ..

Key message on posters and brochures

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Use of same posters in Mekong delta, Vietnam (2006)

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Use of extensionleaflets in Mekongdelta, Vietnam (2006)

Irrigation water used (mm)

CI

FP

1200

1400

1000

800

600

400

200

0

Uppe

r

Uppe

r

Middle

Middle

Lower

Lower

Avera

ge

Avera

ge

2002 Dry season

P-38, Canarem

Waterused(mm)

2003 Dry season 2002 Dry season

Nueva Ecija

2003 Dry season

C

F

1200

1400

1000

800

600

400

200

0

Waterused(mm)

I

P

Dolores DoloresGabaldon Ave AveGabaldon

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Grain yield (t/ha)

CI

FP

Upper

Upper

Middle

Middle

Lower

Lower

AveA

ve

2002 Dry season

3

0

6

2

1

8

4

5

9

Grainyield(t/ha)

7

2003 Dry season

P-38, Canarem

0

2

1

3

5

7

4

6

8

9

Gabaldon Ave AveDolores

Yield

(t/ha)

GabaldonDolores

CI

FP

2002 Dry season 2003 Dry season

Nueva Ecija

FINAL REMARKS (1)

AWD already existed for long time The water tube: pivotal role in dissemination In BD: 10% reduction in water means reducing 40 L of gasoline/ha. If only half of

boro rice area apply AWD, we can save 80 ML of gasoline AWD also reduces Arsenic in the soil and plant

FINAL REMARKS (2): constraints

How to make AWD benefit farmers? Weeds: important to keep flooded 2 wks after transplanting Vote of THANKS

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