1. ERT 468 IRRIGATION & DRAINAGE SYSTEM
Prepared By:
Mdm. Fathin Ayuni Azizan
Lecturer,
Biosystems Engineering
Programme
LECTURE WEEK 10:
MICROIRRIGATION

2. Course Content System type (drip, subsurface drip & sprayer)
System component &
System layout.
Planning & Design
-Requirement for water quality enhancement, operation & maintenance

3. INTRODUCTION
PART 1

4. Top 10 Micro Irrigated Countries
Acreage (Mha)

5. Micro-irrigation system
Localized irrigation methods-> slowly, repetitively & uniformly-> to the plant RZ.
pressure & low discharges-> small-sized wetting patterns.
Ensure water & fertilizer directly to individual plants, reducing the wetted area by wetting only a fraction of the soil surface.
Saves water: high appl. eff. & distribution uniformity.
Popular: potential to increase yields & decrease water, fertilizer & labour requirements.
Applicable: where water supply is limited and/or expensive.
Suitable: sloping or irregularly shaped land (impossible for surface/sprinkler).

6. CHARACTERISTICS OF MI Low flow rate (2-300 LPH)
Low operating pressure (<200 kPa)
Localized, partial wetting-> soil surface & soil volume (<1m dia, <0.6 m depth),
Repetitive water applications (6-20x/day)

7. MAIN TYPEs of MI
Drip/Tricle
Bubbler
Subsurface
Microsprayer

8. Drip (trickle)
“frequent application of small quantities of water at low flow rates & pressures on the soil thro drip emitter”
Most common type of system worldwide
delivering water precisely at the plant RZ where nearly all of the water can be used for plant growth
Water applied at low flow rate but in amount sufficient to replenish CWR on a very frequent basis (usually daily)
Uniformity of application is not affected by wind b’cos the water is applied at the ground surface

9. Typical operating pressure:100 kPa
Appl. rates: 2 – 24 LPH
Appl. Eff. ~ 90%
Popular: in areas where water supplies are limited or recycled water is used
used in farms, commercial GH & residential gardens
Very efficient method: labor & water usage
needs high initial investment but when installed, it required less labor
Liquid or soluble fertilizer can be applied thro this system (Fertigation) & very suitable for automation
Main problem: emitter clogging

10. Drip (trickle) - Utilizations
Row crops
Tobacco
Vegetables
Flowers
Sugarcane
Cotton
Single plant
Fruit tree
Landscape

11. citrus
tobacco

13. Drip for tomato in greenhouses

14. Drip for strawberry in greenhouse

15. Drip for flowers

16. drip for herbs

17. drip for fruit orchards
Micro irrigation is highly suitable for fruit trees
drip for fruit orchards

18. Micro-Sprayer Typical operating pressure: 150kPa
Application rate: 20 – 150 LPH
Application efficiency:~80%
Effective wetting dia.: cm
Nozzle is not rotating
Nozzle placed at the end of tubing (4 mm dia.) & supported by rigid riser
Nozzle also can be placed hanging in PE tubing,
Nozzle with capability of 360o & 180o water distribution.
Water droplet is fine & soft (no injury to the plant)

19. Fixed head
Reaction rotary sprinkler
Fixed head

20. Micro-sprayer (landscape)

21. Overhead micro sprayer (vegetable in greenhouse)

22. OVERHEAD SPRAYER (FLOWER IN GREENHOUSE)

23. Overhead spray-jet for chili in greenhouse

24. Spray-jet for sweet potato

25. SYSTEM COMPONENTS
PART 2

26. SYSTEM COMPONENTS Emitters placed along laterals
to dissipate pressure & discharge
placed along laterals
operated under pressure to discharge water in the form of continuous drops
Water delivery/distribution networks
Main lines, sub-mains, manifolds & headers
Laterals
Control head & monitoring devices
Injectors
Valves & gauges
Pressure regulators
Filters
Pump

28. 1. Emitters
Types of emitters used
(a) Point Source
(b) Line Source

29. On-line and In-line Drippers
(a) Point Source = on-line dripper
(b) Line Source = in-line drippers

30. Recommended Discharge Rates
Types of drip emitter
Pressure
(kPa)
Discharge Rates (L/hr)
Single-outlet point source
100
< 12
Line-source
< 12 per m of strip

31. Micro Sprayer Types Vibrating micro-jet Static Sprayer Rotator
Spinners
Bubbler
Micro-sprinkler

32. Micro Sprayers

33. 2. Water Distribution Networks
Network of pipes/tubes: to convey water from source to laterals
Size: mm diameter
Water from the pump carried to the edge of the field by a single large main
Smaller sub-mains then carry the water to laterals & finally to the emitters

35. Mainlines supply water from the pump->sub-mains
constructed by PVC pipe buried beneath the soil surface
nominal working pressure has to be higher than that of the drip lateral
working pressure of delivery & distribution lines is 60 – 80 m head.

36. Average Flow Velocity (V) and Head Loss Gradient Factors (J) for SDR 41 PVC Thermoplastic Pipe for Various Flowrates (Q) and Smaller Pipe Sizes (Lamm et al. 2007)
PVC Class 100 IPS Plastic Pipe: SDR = C = 150 OD ID
Diameter (mm)
33.40
31.80
48.30
45.90
60.30
57.40
88.90
84.60
Nom. Size (in)
1.00
1.50
2.00
3.00 Q v J
L/s
m/s
m/100 m
0.10
0.13
0.08
0.06
0.01
0.20
0.25
0.28
0.12
0.05
0.30
0.38
0.59
0.18
0.03
0.40
0.50
0.24
0.17
0.15
0.07
0.63
1.52
0.19
0.09
0.60
0.76
2.13
0.36
0.35
0.23
0.11
0.02
0.70
0.88
2.83
0.42
0.47
0.27
0.16
0.80
1.01
3.62
0.48
0.31
0.14
1.26
5.48
0.91
0.39
1.20
1.51
7.68
0.73
1.28
0.46
0.43
0.21
1.40
1.77
10.21
0.85
1.70
0.54
0.57
1.60
2.02
13.08
0.97
2.18
0.62
1.80
2.27
16.26
1.09
2.71
0.32
2.52
19.77
1.21
3.29
0.77
1.11
2.50
4.98
1.68
0.45
1.81
6.98
1.16
2.35
0.53
3.50
2.11
9.28
1.35
3.13
4.00
2.42
11.89
1.55
4.01
0.71
0.61
4.50
2.72
14.79
1.74
4.99
0.75
5.00
1.93
6.06
0.89
0.92
5.50
7.23
0.98
6.00
2.32
8.50
1.07
1.29
8.00
1.42
2.19
10.00
1.78
3.31
12.00
2.14
4.64
14.00
2.49
6.17
16.00
2.85
7.91

37. Manifolds & Headers pipelines of a smaller diameter than the sub-mains
used to simplify operation
constructed with flexible PVC pipe which can be left on the soil surface or buried beneath the soil surface
Mainline or sub-mains to manifold connections are the points, where pressure is needed to regulate & automated control valve may be installed

38. SUB-MAINS distribute water to laterals
usually positioned at right angles to laterals.
pipes are smaller diameter pipelines which are usually flexible PVC pipe
can be left on the soil surface or buried beneath the soil surface

39. LATERALS smallest diameter pipelines of the system.
fitted to the sub-mains or manifolds perpendicularly at fixed positions laid along the plants rows
equipped with emitters at fixed frequent spacing.
constructed of flexible polyvinyl chloride (PVC) or polyethylene hose (PE).
often placed above the ground but it can be buried.

40. Average Flow Velocity (V) and Head Loss Gradient Factors (J) for  Polyethylene Pipe for Various Flowrates (Q) and Smaller Pipe Sizes  (Lamm et al. 2007)
PVC Class 100 IPS Plastic Pipe: SDR = C = 150 ID
Diameter (mm)
15.80
20.90
26.60
35.10
40.90
Nom. Size (in)
0.50
0.75
1.00
1.25
1.50 Q v J
L/min
L/s
m/s
m/100m 2
0.03
0.17
0.30
0.10
0.08 4
0.07
0.34
1.09
0.19
0.28 6
0.51
2.31
0.29
0.59
0.18
0.05
0.02 8
0.13
0.68
3.94
0.39
0.24
0.31
0.14
0.1
0.04 10
0.85
5.96
0.48
1.51
0.47
0.12
0.06 12
0.20
1.02
8.35
0.58
2.12
0.36
0.65
0.21
0.15 14
0.23
1.19
11.11
2.82
0.42
0.87
0.11 16
0.27
1.36
14.22
0.78
3.62
1.12
0.2 18
1.53
17.69
4.50
0.54
1.39 20
0.33
1.70
21.50
0.97
5.47
0.60
1.69
0.44
0.25 22
0.37
1.87
25.65
1.07
6.52
0.66
2.01
0.38
0.53 24
0.40
2.04
30.14
1.16
7.66
0.72
2.36
0.41
0.62
0.3 26
0.43
2.21
34.95
1.26
8.89
2.74
0.45 28
2.38
40.09
10.19
0.84
3.15
0.82 30
1.45
11.58
0.90
3.57
0.52
0.93 35
15.41
1.05
4.75
1.24 40
0.67
1.94
19.73
1.20
6.09
0.69
1.59
0.76 45
2.18
24.54
1.35
7.57
1.98
0.57
0.94 50
0.83
2.42
29.83
1.49
9.20
0.86
2.40
0.63
1.14 60
1.79
12.90
1.03
3.37
1.6 70
1.17
2.09
17.17
1.21
4.48
0.89
2.13 80
1.33
2.39
21.98
1.38
5.74
1.01
2.73 90
1.55
7.14
3.39
100
1.67
1.72
8.68
1.27
4.12
125
2.08
2.15
13.12
6.23
150
2.50
1.9
8.74
175
2.92
2.22
11.62

41. 3. Control Head & Monitoring Devices
Drip irrigation systems can be controlled manually or automatically
Automatic control can be electro-mechanical or electronic.
main line valve & flow meter are also included in the control head
controller is often located next to other components of the control station.
Controller can control the main valve, chemical injection, back flushing of filters, solenoid valves, & other controls located at remote locations in the irrigation system (all or some of these components can be automated)

43. 4. FILTERS water quality enhancement
important for successful operation
IS will fail without careful filtration/treatment of contaminants present in water
remove sand & larger suspended particles
cannot remove dissolved minerals, bacteria & some algae.
3 types:
Screen
Disk
Sand filters

44. 1) Screen filter
2) Sand filter

45. Filtration system for drip
Sand filter
Screen filter
Filtration system for drip

46. 5. PUMPS
selection of type & size of pump depends on the amount of water required, the desired pressure & the location of the pump relative to the distribution network.
electric power units or internal combustion engine driven pumps are equally adaptable
electric power unit is preferred because it is easier to automate.

47. SYSTEM LAYOUT
PART 3

48. SYSTEM LAYOUT Pipe & control head: located in the centre of the field
Pump: located outside of field (if the water source is from lake/reservoir/river)
control head will generally contain:
pump station & associated controls,
system valves,
pressure gauges
water treatment equipment
Water flows from the pump into a manifold & then into lateral lines thro a header pipe

49. (a) Field Layout with Irrigation Zones

50. (b) Layout of Irrigation Zone

51. (c) Arrangement of the Water Supply, Control Head, Water Treatment & Chemigation Equipment

52. Lateral Layout Basic types: fork, herringbone comb-shaped
(a) Fork type
(b) Herringbone type
(c) Comb type

53. Emitters Arrangement

54. . Drip Irrigation System Layout MARDI Station, Jelebu IRRIGATION BLOCK
AIR RELEASE VALVE
END CAP .
DRIP EMITTER
SUB -
MAIN PIPE
LATERAL
MAIN PIPE -
AIR RELEASE VALVE
SUB
END SLEEVE
IRRIGATION BLOCK
MAIN PIPE
MAIN PIPE
END CAP
GATE VALVE
SAND FILTER
MAIN PIPE
SUB
SCREEN FILTER -
NON -
RETURN VALVE
MAIN PIPE
RESERVOIR
SUB -
MERSIBLE PUMP
SUB -
MERSIBLE PUMP
(HIGH HEAD)
(LOW HEAD)
INTAKE SUMP
COLLECTOR SUMP
MARDI Station, Jelebu

55. PLANNING & DESIGN
PART 4

56. Designing MI 1. Emitter/nozzle selection Dripper Sprayer
One or more dripper
Pressure compensated or not
Discharge rate (2 – 8 l/h)
Operating pressure (100kPa)
Wetted diameter (0.5 m)
Sprayer
Spray-jet or spinner
Discharge (30 – 60 l/h)
Operating pressure (150 kPa)
Wetted diameter (1- 2 m)
Factor influence emitter/nozzle selection
Soil characteristic
Land slope
Crop water requirement
Water sources

57. 2. Lateral design Pipe size Pipe length Pipe layout
13, 16, 19, 21 & 25 mm dia.
Pipe length
Shortest possible to reduce pressure different at up-stream & down-stream (<50m)
Deciding factor: discharge per unit length, pipe size, land slope & plot shape
Pipe layout
One lateral per plant row
Laid on soil surface or buried (15 cm)
On flat area: laid on both side of manifold
On slopeland: laid parallel to contour or down the slope
Allow for pipe expansion & contraction (zigzag)

58. Average Flow Velocity (V) and Head Loss Gradient Factors (J) for  Polyethylene Pipe for Various Flowrates (Q) and Smaller Pipe Sizes  (Lamm et al. 2007)
PVC Class 100 IPS Plastic Pipe: SDR = C = 150 ID
Diameter (mm)
15.80
20.90
26.60
35.10
40.90
Nom. Size (in)
0.50
0.75
1.00
1.25
1.50 Q v J
L/min
L/s
m/s
m/100m 2
0.03
0.17
0.30
0.10
0.08 4
0.07
0.34
1.09
0.19
0.28 6
0.51
2.31
0.29
0.59
0.18
0.05
0.02 8
0.13
0.68
3.94
0.39
0.24
0.31
0.14
0.1
0.04 10
0.85
5.96
0.48
1.51
0.47
0.12
0.06 12
0.20
1.02
8.35
0.58
2.12
0.36
0.65
0.21
0.15 14
0.23
1.19
11.11
2.82
0.42
0.87
0.11 16
0.27
1.36
14.22
0.78
3.62
1.12
0.2 18
1.53
17.69
4.50
0.54
1.39 20
0.33
1.70
21.50
0.97
5.47
0.60
1.69
0.44
0.25 22
0.37
1.87
25.65
1.07
6.52
0.66
2.01
0.38
0.53 24
0.40
2.04
30.14
1.16
7.66
0.72
2.36
0.41
0.62
0.3 26
0.43
2.21
34.95
1.26
8.89
2.74
0.45 28
2.38
40.09
10.19
0.84
3.15
0.82 30
1.45
11.58
0.90
3.57
0.52
0.93 35
15.41
1.05
4.75
1.24 40
0.67
1.94
19.73
1.20
6.09
0.69
1.59
0.76 45
2.18
24.54
1.35
7.57
1.98
0.57
0.94 50
0.83
2.42
29.83
1.49
9.20
0.86
2.40
0.63
1.14 60
1.79
12.90
1.03
3.37
1.6 70
1.17
2.09
17.17
1.21
4.48
0.89
2.13 80
1.33
2.39
21.98
1.38
5.74
1.01
2.73 90
1.55
7.14
3.39
100
1.67
1.72
8.68
1.27
4.12
125
2.08
2.15
13.12
6.23
150
2.50
1.9
8.74
175
2.92
2.22
11.62

59. 3. Manifold design Pipe size Pipe layout Made: PVC & buried 15-30 cm
25 – 100 mm dia.
Length depend on lateral number & spacing
Pipe layout
On slopeland:
pipe laid down the slope so that lateral parallel to contour
inlet at upstream of pipe

60. Average Flow Velocity (V) and Head Loss Gradient Factors (J) for SDR 41 PVC Thermoplastic Pipe for Various Flowrates (Q) and Smaller Pipe Sizes (Lamm et al. 2007)
PVC Class 100 IPS Plastic Pipe: SDR = C = 150 OD ID
Diameter (mm)
33.40
31.80
48.30
45.90
60.30
57.40
88.90
84.60
Nom. Size (in)
1.00
1.50
2.00
3.00 Q v J
L/s
m/s
m/100 m
0.10
0.13
0.08
0.06
0.01
0.20
0.25
0.28
0.12
0.05
0.30
0.38
0.59
0.18
0.03
0.40
0.50
0.24
0.17
0.15
0.07
0.63
1.52
0.19
0.09
0.60
0.76
2.13
0.36
0.35
0.23
0.11
0.02
0.70
0.88
2.83
0.42
0.47
0.27
0.16
0.80
1.01
3.62
0.48
0.31
0.14
1.26
5.48
0.91
0.39
1.20
1.51
7.68
0.73
1.28
0.46
0.43
0.21
1.40
1.77
10.21
0.85
1.70
0.54
0.57
1.60
2.02
13.08
0.97
2.18
0.62
1.80
2.27
16.26
1.09
2.71
0.32
2.52
19.77
1.21
3.29
0.77
1.11
2.50
4.98
1.68
0.45
1.81
6.98
1.16
2.35
0.53
3.50
2.11
9.28
1.35
3.13
4.00
2.42
11.89
1.55
4.01
0.71
0.61
4.50
2.72
14.79
1.74
4.99
0.75
5.00
1.93
6.06
0.89
0.92
5.50
7.23
0.98
6.00
2.32
8.50
1.07
1.29
8.00
1.42
2.19
10.00
1.78
3.31
12.00
2.14
4.64
14.00
2.49
6.17
16.00
2.85
7.91

61. 4. Main pipe design Pipe size Pipe layout Made of PVC or HDPE pipe
mm dia
Pipe layout
Laid across the centre of the farm & buried below surface

62. 5. Pump & Engine design Pump size depend: on water discharge
Pump hp = (Q (gpm) x head (ft))/3300 x efficiency
Engine hp = pump hp/efficiency

63. 6. Filtration system design Type of filter
Screen
Grooved disc
Media
Filter size
Depend on water discharge (+20%) & mesh size ( mesh)
Screen & Grooved disc (30 – 1000 m3/h)
Media (45 – 450 m3/h)

64. DESIGN 1 Design drip irrigation system for citrus plot
Plant rows: 30 with 15 plants per row.
Plant spacing: 3 x 3 m
Plot size is 100 x 50 m (0.5 ha).
Soil type: clay loams (WHC:183 mm/m)
RZ depth of citrus: 0.61m (MAD 50%)
A pressure compensated emitter, q= ?? (8 l/h/plant)

65. Calculate
lateral pipe size
Manifold & main pipe size
Filter size
Filter type

66. Design Solution Step 1: Plant layout (row & plant/row)
Step 2: Plant water requirement (30 lpd), soil water storage
capacity, depth per irrigation, irrigation frequency
Step 3: Emitter selection
Step 4: Lateral design
Step 5: Manifold design
Step 6: Mainline design
Step 7: Filtration system design
Step 8: Pump & power requirement