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

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

INTRODUCTION PART 1

Top 10 Micro Irrigated Countries Acreage (Mha)

Micro-irrigation system Localized irrigation methods-> slowly, repetitively & uniformly-> to the plant RZ. Operates @low 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).

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)

MAIN TYPEs of MI Drip/Tricle Bubbler Subsurface Microsprayer

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

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

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

citrus tobacco

Drip for tomato in greenhouses

Drip for strawberry in greenhouse

Drip for flowers

drip for herbs

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

Micro-Sprayer Typical operating pressure: 150kPa Application rate: 20 – 150 LPH Application efficiency:~80% Effective wetting dia.: 60-120 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)

Fixed head Reaction rotary sprinkler Fixed head

Micro-sprayer (landscape)

Overhead micro sprayer (vegetable in greenhouse)

OVERHEAD SPRAYER (FLOWER IN GREENHOUSE)

Overhead spray-jet for chili in greenhouse

Spray-jet for sweet potato

SYSTEM COMPONENTS PART 2

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

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

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

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

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

Micro Sprayers

2. Water Distribution Networks Network of pipes/tubes: to convey water from source to laterals Size:10 - 150 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

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.

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 = 41 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

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

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

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.

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 = 26 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

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)

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

1) Screen filter 2) Sand filter

Filtration system for drip Sand filter Screen filter Filtration system for drip

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.

SYSTEM LAYOUT PART 3

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

(a) Field Layout with Irrigation Zones

(b) Layout of Irrigation Zone

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

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

Emitters Arrangement

. 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

PLANNING & DESIGN PART 4

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

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)

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 = 26 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

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

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 = 41 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

4. Main pipe design Pipe size Pipe layout Made of PVC or HDPE pipe 50- 150 mm dia Pipe layout Laid across the centre of the farm & buried below surface

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

6. Filtration system design Type of filter Screen Grooved disc Media Filter size Depend on water discharge (+20%) & mesh size (100-200 mesh) Screen & Grooved disc (30 – 1000 m3/h) Media (45 – 450 m3/h)

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)

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

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