1. LOW COST MICROTUBE DRIP SYSTEM Presentation by J. N. Roy

2. General design strategy – based on locally available components – limited skill and low capital requirements to design, service and maintain – income generation potential (cover the investment cost in one irrigation season) – available in a range of small packages (20 square meter – 1 hectare) – easy to understand, operate and maintain by unsophisticated users – work at 1-3 meter inlet pressure head

3. Technical specifications Lay flat lateral tube Wall thickness - 125 + 5 microns (5 + 0.2 mils) - 250 + 5 microns (10 + 0.2 mils) - 250 + 5 microns (10 + 0.2 mils) Width 26 + 0.5 mm Microtube emitter

4. For vegetable and regular row crop – 20 cm (8 inch) with a tight overhand knotFor vegetable and regular row crop – 20 cm (8 inch) with a tight overhand knot For lateral with double microtube – 10 cm longer than half the row widthFor lateral with double microtube – 10 cm longer than half the row width Horticulture – 1 to 1.5 meter (3.3 – 5 feet)Horticulture – 1 to 1.5 meter (3.3 – 5 feet) No of microtube per horticulture crop (1 microtube for banana & papaya, 4 microtubes for citrus)No of microtube per horticulture crop (1 microtube for banana & papaya, 4 microtubes for citrus) Inlet end of microtube pointing downwardsInlet end of microtube pointing downwards Microtube length

5. Uniformity of water distribution or emission uniformity (EU) used as basic measurement to measure the performance of drip irrigation system Inlet pressure head 1-3 meters Lateral length Maximum 50 meter from one end Submain - both flexible semi lay flat and rigid pipe Uniformity standard

6. EU is dependent on the combined effect of Water supply head available Elevation differences throughout the irrigated area Friction losses Discharge characteristics and Manufacturers coefficient of uniformity of microtubes

7.  Coefficient of variation for uniformity Measure of uniformity for post installation evaluation of low cost microtube drip system

8. CVU above 88 % is excellent CVU between 88 % and 80% is good CVU between 88 % and 72% is fair CVU between 72 % and 62 % is marginally accepted Recommended CVU values for low cost microtube drip systems

9. Lateral inlet pressure head Microemitter spacing Lateral length Lateral drip tape inside diameter Minor loss due to the insertion of microtube emitters into the drip tape (0.1 meter) Microtube emitter pressure head\discharge relation curve Coefficient of variation of the microtube emitter, based on bench test data Low cost microtube drip lateral design The system design tables developed on the basis of following input variables

10. Row and vegetable microtube drip-tape hydraulic design tables for laterals on zero slope Inlet Head, H L (M) Microtub e Spacing S e (cm) Lateral/Row Length 20 mLatera/Row Length 30 m Q L (lpm) q a (lph) h f (m) EU L (%) Q L (lpm) q a (lph) h f (m) EU L (%) 0.50 45 60 75 90 2.17 1.66 1.37 1.12 2.96 3.01 3.04 3.06 0.04 0.02 0.02 0.01 94 95 95 96 3.04 2.38 1.96 1.64 2.72 2.86 2.93 2.98 0.11 0.07 0.05 0.03 91 93 94 95 0.75 45 60 75 90 2.91 2.23 1.84 1.51 3.97 4.06 4.09 4.12 0.07 0.04 0.03 0.02 94 95 95 96 4.05 3.19 2.63 2.20 3.63 3.83 3.94 4.01 0.18 0.11 0.08 0.06 91 93 94 95 1.00 45 60 75 90 3.59 2.76 2.28 1.87 4.90 5.01 5.06 5.10 0.10 0.06 0.04 0.03 94 95 95 96 4.96 3.93 3.23 2.72 4.44 4.71 4.85 4.94 0.25 0.16 0.11 0.08 90 93 94 94 1.50 45 60 75 90 4.82 3.71 3.07 2.52 6.58 6.74 6.81 6.87 0.16 0.10 0.07 0.05 94 95 95 95 6.60 5.25 4.34 3.65 5.91 6.30 6.50 6.64 0.41 0.27 0.19 0.14 90 92 94 94 2.00 45 60 75 90 5.94 4.58 3.79 3.11 8.10 8.32 8.42 8.49 0.23 0.14 0.10 0.07 94 95 95 95 8.07 6.44 5.34 4.50 7.23 7.73 8.01 8.19 0.58 0.38 0.27 0.20 89 92 93 94 2.50 45 60 75 90 6.98 5.39 4.46 3.67 9.52 9.79 9.91 10.01 0.31 0.19 0.14 0.10 94 95 95 95 9.43 7.55 6.27 5.29 8.45 9.06 9.40 9.62 0.76 0.50 0.36 0.26 89 92 93 94 3.00 45 60 75 90 7.96 6.15 5.10 4.20 10.86 11.19 11.33 11.45 0.39 0.24 0.17 0.12 93 95 95 95 10.71 8.60 7.15 6.04 9.59 10.32 10.72 10.99 0.94 0.63 0.45 0.33 89 92 93 94 4.00 45 60 75 90 9.80 7.59 6.30 5.19 13.36 13.80 13.99 14.15 0.56 0.35 0.25 0.18 93 94 95 95 13.08 10.54 8.78 7.44 11.71 12.65 13.18 13.53 1.33 0.90 0.65 0.48 88 91 93 94 5.004511.5115.690.749315.2613.671.7488

11. Inlet Head, H L (M) Microtube Spacing S e (cm) Latera/Row Length 40 mLatera/Row Length 50 m Q L (lpm) q a (lph) h f (m) EU L (%) Q L (lpm) q a (lph) h f (m) EU L (%) 0.50 45 60 75 90 3.62 2.95 2.45 2.10 2.44 2.65 2.78 2.86 0.18 0.13 0.09 0.07 87 90 92 93 3.98 3.34 2.88 2.51 2.15 2.41 2.58 2.69 0.26 0.19 0.15 0.12 81 87 89 91 0.75 45 60 75 90 4.78 3.93 3.28 2.81 3.22 3.52 3.71 3.83 0.30 0.21 0.15 0.11 86 90 92 93 5.22 4.41 3.81 3.34 2.82 3.19 3.42 3.58 0.41 0.30 0.24 0.19 80 86 89 90 1.00 45 60 75 90 5.82 4.80 4.02 3.45 3.92 4.30 4.55 4.71 0.41 0.30 0.21 0.16 85 89 91 93 6.32 5.37 4.66 4.06 3.42 3.88 4.17 4.38 0.56 0.43 0.34 0.27 79 85 88 90 1.50 45 60 75 90 7.67 6.37 5.36 4.61 5.17 5.70 6.07 6.29 0.67 0.48 0.35 0.27 84 88 91 92 8.28 7.07 6.16 5.43 4.47 5.11 5.52 5.82 0.89 0.68 0.55 0.44 77 84 87 89 2.00 45 60 75 90 9.32 7.77 6.56 5.66 6.28 6.96 7.43 7.72 0.93 0.68 0.50 0.39 83 88 90 92 10.01 8.59 7.51 6.64 5.41 6.21 6.73 7.11 1.22 0.95 0.77 0.62 76 83 86 89 2.50 45 60 75 90 10.83 9.07 7.68 6.64 7.30 8.12 8.69 9.05 1.20 0.89 0.66 0.51 83 87 90 92 11.60 9.98 8.75 7.75 6.27 7.22 7.84 8.30 1.57 1.23 1.00 0.81 75 82 86 88 3.00 45 60 75 90 12.25 10.29 8.73 7.56 8.26 9.21 9.88 10.30 1.48 1.10 0.82 0.64 82 87 90 92 13.08 11.29 9.91 8.79 7.07 8.16 8.88 9.42 1.92 1.52 1.24 1.01 75 82 85 88 4.00 45 60 75 90 14.86 12.53 10.67 9.27 10.02 11.22 12.08 12.64 2.06 1.55 1.16 0.90 81 86 89 91 15.80 13.69 12.06 10.73 8.54 9.90 10.80 11.49 2.64 2.11 1.73 1.43 73 81 85 87 5.004517.2611.632.668018.289.883.3772