Water Saving Irrigation

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Transcript Water Saving Irrigation

Rice Production Course
Water-Saving Irrigation in Rice
R. Lampayan
CSWS, IRRI
Content
• Introduction: the water crisis
• Water-saving technologies
• Practical experiences
• Sustainability issues
• Conclusions
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Rice grows under lowland conditions:
puddled soil, permanently flooded
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Rice and water
• 75% of rice is irrigated (75 m ha)
• Rice requires much water: 3000-5000 l kg-1 rice
• Irrigated areas consume 80% of all fresh water used;
Asia: > 50% of this is for rice
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Pressure to produce more food (rice) is getting
greater because 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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Is this the future for rice production…….
?
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Competition, some examples in rice areas….
Beijing: 2001: ban on flooded rice
ZIS (160,000 ha)-city, industry
Irrigation
Other Uses
Sectoral Share
ZIS:
100
90
80
70
60
50
40
30
20
10
0
1965
1970
1975
1980
1985
YEAR
Ganges river: India-Bangladesh
Cauvery river: Karnataka-Tamil Nadu
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1990
1995
2000
Reduced river flows
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Tubewells and pumps for irrigation
70
60
50
40
India
China
30
20
10
0
1966
1995
India (2000): 5-6 million irrigation tubewells
N China (2001): 3-4 million irrigation tubewells
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Groundwater depletion
1-1.5 m/y
0.7 m/y
Arsenic!
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Conclusion
Need to grow rice using less water in water-scarce
or water-costly areas
• Produce enough rice for growing population
• Decrease cost of rice production
• Save ‘little’ water in rice => free-up ‘much’ water
for irrigation elsewhere and for use by other
sectors (industry, cities, other crops)
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To mitigate the looming water crisis,
we need to
“Produce more rice with less water”
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Field water balance lowland rice
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Water requirements in lowland rice
Land preparation
Evapotranspiration
- wet season
- dry season
Seepage & percolation
- heavy clays
- loamy/sandy soils
Total season
Typical value
Daily
mm d-1
Season (100 d)
mm
175-750
4-5
6-7
400-500
600-700
1-5
25-30
100-500
2500-3000
: 675-4450 mm
: 1500 mm
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Water-saving measures
•
•
•
•
•
•
•
•
•
Good puddling
Good bund maintenance
Land leveling
Crack plowing
Short land preparation phase
Communal seed beds
Efficient use of rainfall (cropping calendar)
Direct wet seeding
……
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Water-saving irrigation technologies:
Reduce
seepage, percolation and evaporation
• Saturated soil culture
• Alternate wetting and drying
• Aerobic rice
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Field water depths in
alternate wetting
Field water depth (mm)
60
50
40
30
20
10
0
0
10
20
transp.
Early
recovery
tillering
30
Late
tillering
40
50
60
70
PI to complete
flowering
80
90
100 110
grain filling Maturity
Days after Transplanting
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Continuously flooded
Alternate wetting and
drying
Yield (t/ha)
10
9
8
7
6
5
4
3
2
1
0
TL99
TL00
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PR01
Continuously flooded
Alternate wetting and
drying
Irrigation water (mm)
800
700
600
500
400
300
200
100
0
Tuanlin 1999
Tuanlin 2000
PhilRice 2001
Note: heavy clay soil with shallow groundwater (0-30 cm deep)
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Guimba 88-90 (Tabbal et al., 2002)
Silty clay loam, groundwater 70-200 cm
Yield (t/ha)
8
6
1988
4
1989
1990
2
0
500
1,000
1,500
2,000
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2,500
Total water (mm)
A fundamental approach to reducing
water requirements in rice?
Treat rice like any other (irrigated) crop:
No puddling, no standing water, aerobic soil
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Upland rice
Breeding:
Aerobic soil
Drought tolerant
Weed competitive
Adverse soil conditions
Low inputs (!)
=> Stable but low yields
Unfavorable uplands
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Different idea of rice like upland crop
Breeding: from upland rice…
Aerobic soil
Input responsive
Lodging resistant
Weed competitive
=> Stable and high yields
Lowland HYV traits
Water-short irrigated areas
‘Favorable’ uplands
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Improved upland…
Dryland Rice…
Han Dao…
Aerobic Rice…
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New Aerobic Rice
Girls…
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Early evidence: Brazil
• Active program to develop upland rice varieties
and management techniques since the 80’s
=> High-yielding aerobic varieties: 5-7 t ha-1 with
high inputs
• State of Mato Grosso: 250,000 ha commercial
production (sprinkler irrigated)
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Aerobic rice, Mato Grosso, Brasil
Guimarães and Stone, 2000
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Early evidence: North China
• Program to improve upland rice => Aerobic rice
varieties with yield potential of 6-7 t ha-1
Adoption on estimated 190,000 ha (2001) in
• Rainfed areas where rainfall is insufficient to
sustain lowland rice production
• Irrigated areas where water is scarce/expensive
• Salt-affected areas
• Flood-prone areas
Q: What is water use, how to manage the crop?
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Hydrology field experiment Beijing, 2001:
Explore aerobic rice yield and irrigation water use
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Total water input (mm)
1400
1200
1000
800
600
400
200
0
Flood
W1
W2
W3
W4
W5
Water treatment (Rainfall)
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Yield (t/ha)
9
8
7
6
5
Lowland
Aerobic 1
Aerobic 2
4
3
2
1
0
1394
644
577
586
519
469
Flooded ---------------- Aerobic -----------------IRRI: Rice Production Course
Water (mm)
IRRI, Philippines: 3-4 varieties each season
one flooded and one aerobic treatment
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IRRI, 2001 DS: yield (t ha-1) in K6/7
8
7
6
5
Flooded
Aerobic
4
3
2
1
0
IR43
B6144F
Apo+
Fertilizer: 180-60-40 kg ha-1 NPK
Pests and diseases: mole crickets (aerobic), stem
borer, sheath blight;
lodging in B6144F
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IRRI, 2002 DS: yield (t ha-1) in K6/7
8
7
6
5
Flooded
Aerobic
4
3
2
1
0
IR43
IR64
Apo+
Fertilizer: 120-60-40 kg ha-1 NPK
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Magat
Water input, including land preparation (mm)
2000
1800
1600
1400
1200
1000
800
600
400
200
0
Flooded
Aerobic
Irrigation
Rainfall
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WS2002
DS2002
WS2001
DS2001
WS2002
DS2002
WS2001
DS2001
Lining of
bunds
Practical experiences
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Case study Tarlac & Nueva
Ecija:
Introducing alternate
wetting and drying to
farmers using shallow
or deep wells for irrigation
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Monitoring inputs:
Irrigation water, seeds,
fertilizer, pesticides,
labor use, etc.
And outputs:
Grain yield and quality
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Irrigation water used (mm)
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Grain yield (t/ha)
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Comparison between farmers’ practice and alternate wetting
and drying (dry season 2001)
Farmers’
practice
Alternate
wetting and
drying
Difference
Total water used*
(mm)
500
310
190
Pump O&M cost
($ ha-1)
112
69
43
Yield (t ha-1)
5.7
5.5
0.2
Particulars
* From transplanting up to harvesting
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Partial budget comparison ($ ha-1)
Farmers’
practice
Alternate wetting
and drying
Savings
Gross benefits
944
911
-33
Variable irrigation cost
148
96
52
‘Net’ benefits
796
815
19
Particulars
Comments irrigation manager and farmer community: can
irrigate 30% more area with same amount of water !!
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Case study Tarlac and
Nueva Ecija, Philippines:
Aerobic Rice
Crop establishment (traditional
technologies)
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Farmer-participatory development; central
Luzon. 2003: develop also modern technologies
Laser-guided land leveling
Automated seeder with basal
fertilizer application
Labor saving
Efficient fertilizer use
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Flush irrigation
of the field only!
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Weed control:
traditional
technology
(plough,
lithao,
sagad)
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Results aerobic rice WS 2002; Canarem, Tarlac
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Varieties:
• Apo
• UPLRI5
• Magat (Hybrid)
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Grain yield (T/ha)
7
Low-tech
High-tech
Yield range:
APO
(HT)
(LT)
Yield range:
APO
: 4.1 - 5.9 t/ha
UPLRI-5 : 4.0 - 5.6 t/ha
Magat
: 4.5 - 5.4 t/ha
: 2.0 – 6.6 t/ha
: 2.0 – 6.0 t/ha
UPLRI-5 (HT) : 3.3 – 5.3 t/ha
(LT) : 2.2 - 5.3 t/ha
APO
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UPLRI-5
Sustainability issues with
increased aerobic conditions
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Aerobic rice, Mato Grosso, Brasil
Guimarães and Stone, 2000
Rice production system
Rice after 3 years soybeans
Rice after 1 years soybeans
Rice monocrop (5 years)
Yield (kg ha-1)
4,325
2,577
1,160
Fertilization 300 kg of 4-30-16 N,P,K at planting;
150 kg ammonia sulfate
50Course
DAS
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Field experiments at Dapdap (dry season)
• Irrigation experiment (4 treatments)
• Nitrogen experiment (5 treatments)
Mixed upland-lowland area with sandy-loam soil
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No more crop growth after tillering….
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Roots affected by nematodes
Healthy
Field experiment
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Rep
V1
Variety
V2
V3
W1
W2
W3
W4
1.26
0
0
0.33
0.76
0
0
0
0.96
0
0
0
0.99
0.00
0.00
0.11
II
W1
W2
W3
W4
4.14
0
0
0.47
4.69
0
0
0.68
3.07
0
0
1.11
3.97
0.00
0.00
0.75
III
W1
W2
W3
W4
3.52
0
0
0.52
4.29
0
0
0.17
3.93
0
0
0
3.91
0.00
0.00
0.23
IV
W1
W2
W3
W4
3.97
0
0
0.71
5.68
0
0
0
4.87
0
0
0
4.84
0.00
0.00
0.24
I
Treatment
Mean
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Irrigation
experiment
Varieties:
V1 = Apo
V2 = Magat
V3 = PSB Rc 98
Irrigation:
W1=2/week
W2=1/week
W3=1/2 week
W3=variable
Rep
V1
Variety
V2
V3
N1
N2
N3
N4
N5
0.46
0.91
0.08
0.24
0.71
0
0.58
0.21
0.08
0.35
0
0.75
0.63
0.29
0.12
0.15
0.75
0.31
0.20
0.39
II
N1
N2
N3
N4
N5
0.94
0.12
0.42
0.73
3.27
0
0.59
0.54
1.5
2.46
0.37
1.18
1.01
1.96
1.54
0.44
0.63
0.66
1.40
2.42
III
N1
N2
N3
N4
N5
0
0.3
1.65
1.04
1.03
0.82
0.45
2.25
0
1.29
0.68
1.6
0.26
0.53
1.35
0.50
0.78
1.39
0.52
1.22
IV
N1
N2
N3
N4
N5
0.74
2.6
2.33
2.6
0.28
1.41
2.03
1.12
1.68
0.54
1.4
0.28
0.54
1.44
0.29
1.18
1.64
1.33
1.91
0.37
!
Treatment
Mean
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Nitrogen
experiment
Varieties:
V1 = Apo
V2 = Magat
V3 = PSB Rc 98
Nitrogen:
N1 = 0 kg
N2 = 100 kg
N3 = 140 kg
N4 = 180 kg
N5 = 220 kg
Nematode count at harvest; nitrogen experiment
4500
4000
3500
3000
Apo
Magat
PSB Rc 98
2500
2000
1500
1000
500
0
0
100
140
180
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220
kg N ha-1
Nematode count from lowland rice farmers
4500
4000
3500
3000
2500
2000
1500
1000
500
0
1 4 7 10 13 16 19 22 25 28 31 34 37 40 43
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Nematode count/g fresh root (Meloidogyne graminicola)
2000
2001
2002
2003
Wet
season
Dry
season
Wet
season
Dry
season
Wet
season
Dry
season
AA
6
875
491
2530
1499
2089
AF
9
279
11
1760
27
3054
FF
2
6
4
134
34
380
Sampled from roots at harvest
Aerobic
Flooded
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Wet
season
Conclusions for
Controlled Irrigation
 An average water savings of about 20% was attained in
both deepwell and shallow tubewell systems.
 Forty percent (40%) of water savings has also been
attained in some fields.
 No significant yield difference has been observed
between CI and FP plots.
 Farmers achieved an average increased net profit of
about $20 per ha in deepwell and shallow tubewell
systems.
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Conclusions tropical aerobic rice
Where are we after 2 years in the program?
1. Identified varieties with yield potential of 6 t ha-1, using
about half the water used in lowland rice (Apo, Magat,
UPLRI5, and more)
2. Rough management recommendations that can deliver
about 4.5 t ha-1 of the yield potential
3. Established a successful partnership to fully develop
the aerobic rice technology (IRRI, NIA, PhilRice and
farmers)
4. Under water scarcity: extremely urgent to develop
sustainable crop rotations (nematodes!)
5. We stand at a successful beginning
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AWD, aerobic rice
“Target domain”
Yield
Diversification
(nonrice crops)
Crack plowing
Compaction
Good puddling
……..
AWD
Flooded
lowland
Aerobic
rice
Upland
Low
High
Water availability
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