1. 1 B3.2.3Irrigation techniques Sprinkler irrigation Uniform application by “artificial rain” Good application efficiencies (0.7 – 0.8) –dependent on wind, temperature, humidity Fairly terrain independent (but design must take terrain into account) Can have a low labour content But High(ish) investment cost High maintenance cost due to pumping Can be complex to run

2. 2 B3.2.3Irrigation techniques Sprinkler irrigation: Criteria (from Cornish) Must permit cost recovery within one to two years (and double investment in a short time) Must be suitable for use on small and irregular shaped plots Must require only simple maintenance and tools Have a low risk of component failure Be simple to operate Be durable and reliable – able to withstand rough and frequent handling without serious damage

3. 3 B3.2.3Irrigation techniques Sprinkler irrigation: System layout

4. 4 B3.2.3Irrigation techniques Sprinkler irrigation

5. 5 B3.2.3Irrigation techniques Sprinkler irrigation: Drag hose system

6. 6 B3.2.3Irrigation techniques Sprinkler irrigation: Sprinkler

7. 7 B3.2.3Irrigation techniques Sprinkler irrigation: Spray pattern

8. 8

9. 9 B3.2.3Irrigation techniques Sprinkler irrigation: Spray pattern: Variation in pressure

10. 10 B3.2.3Irrigation techniques Sprinkler irrigation: Variation in pressure

11. 11 B3.2.3Irrigation techniques Sprinkler irrigation: Solid set system

12. 12 B3.2.3Irrigation techniques Sprinkler irrigation: Hand move laterals

13. 13 B3.2.3Irrigation techniques Sprinkler irrigation: Hop along system

14. 14 B3.2.3Irrigation techniques Sprinkler irrigation: Drag hose system

15. 15 B3.2.3Irrigation techniques Sprinkler irrigation: Drag hose system

16. 16 B3.2.3Irrigation techniques Sprinkler irrigation: Centre pivot system

17. 17 B3.2.3Irrigation techniques Sprinkler irrigation: Centre pivot system

18. 18 B3.2.3Irrigation techniques Sprinkler irrigation: Centre pivot system

19. 19 B3.2.3Irrigation techniques Sprinkler irrigation: Centre pivot system

20. 20 B3.2.3Irrigation techniques Sprinkler irrigation: Linear move system

21. 21 B3.2.3Irrigation techniques Sprinkler irrigation: Linear move system

22. 22 B3.2.3Irrigation techniques Sprinkler irrigation: Linear move system

23. 23 B3.2.3Irrigation techniques Sprinkler irrigation: Mobile raingun

24. 24 B3.2.3Irrigation techniques Sprinkler irrigation: Mobile raingun

25. 25 B3.2.3Irrigation techniques Sprinkler irrigation: Appropriateness TypeDivisibilityMaintenanceRiskOperator skill Durability Hand move32223 Drag Hose34233 “Low-tech”34333 Perforated pipe32132 Side roll02222 Side move01111 Static gun22213 Boom02112 Traveling gun21112 Centre Pivot01112 Liner move01112 Solid set33233 Piped distribution33334

26. 26 B3.2.3Irrigation techniques Sprinkler irrigation: Appropriateness TypeScoreCrops Piped distribution16All “Low tech”16All Drag hose15All Solid set14Orchards Hand move laterals12All Perforated pipe11Soft fruit and veg Static gun10Cereals, Row crops Side roll7Short cereals, row crops Traveling gun7Cereals, Row crops Boom6Cereals, Row crops Centre pivot5Cereals, Row crops Linear move5Cereals, Row crops Side move4Cereals, Row crops

27. 27 B3.2.4Irrigation techniques Micro irrigation Excellent efficiency (>0.9) –“little and often” - plants have ideal water all the time –As little as 30% of the root zone is wetted Not sensitive to slope Good for mineralised water Good for injected fertiliser But Very expensive Needs well filtered water Can be complex to operate ands maintain

28. 28 B3.2.4Irrigation techniques Micro irrigation: Improvements CropYield Increase (%)Water saving (%) Bananas5245 Grapes2348 Sweet lime5061 Pomegranate9845 Papaya7568 Tomato5039 Watermelon8836 Okra1640 Cabbage260 Chillies4462 Sweet Potato3960 Beetroot779 Radish277 Sugar cane3356 Cotton2653

29. 29 B3.2.4Irrigation techniques Micro irrigation: Layout

30. 30 B3.2.4Irrigation techniques Micro irrigation: Drip irrigation

31. 31 B3.2.4Irrigation techniques Micro irrigation: Root zone

32. 32 B3.2.4Irrigation techniques Micro irrigation: Infiltration Sandy soilClay soil

33. 33 B3.2.4Irrigation techniques Micro irrigation: Emitters

34. 34 B3.2.4Irrigation techniques Micro irrigation: Thick walled drip hose

35. 35 B3.2.4Irrigation techniques Micro irrigation: Thin walled drip hose

36. 36 B3.2.4Irrigation techniques Micro irrigation: Bubblers

37. 37 B3.2.4Irrigation techniques Micro irrigation: Microsprinklers

38. 38 B3.2.4Irrigation techniques Micro irrigation: Microsprinklers

39. 39 B3.2.4Irrigation techniques Micro irrigation: Appropriateness TypeDivisibilityMaintenanceRiskOperator skill Durability Drip emitters33111 Drip hose (thick)33111 Drip hose (thin)33111 Micro sprayers33213 Pressurised bubbler33334 Gravity fed bubbler33312

40. 40 B3.2.4Irrigation techniques Micro irrigation: Appropriateness TypeScoreCropsCost (USD 1990) Piped distribution16All800 “Low tech” Sprinkler16All Pressurised bubbler16Orchard3,000 Drag hose Sprinkler15All675 Solid set Sprinkler14Orchards3,500 Hand move laterals Sprinkler12All675 Micro sprayers12Orchard, Soft fruit and3,500 Gravity fed bubbler12Orchard3,500 Perforated pipe Sprinkler11Soft fruit and vegetables800 Static gun Sprinkler10Cereals, Row crops950 Drip emitters9Wide row fruit and vegetables3,500 Drip hose (thick)9Wide row fruit and vegetables5,000 Drip hose (thin)9Wide row fruit and vegetables3,000 Side roll Sprinkler7Short cereals, row crops1,500 Traveling gun Sprinkler7Cereals, Row crops1,500 Note: Skilled worker’s wages in Sri Lanka $4/day, Uganda, $2.5/day

41. 41 B3.2.4Irrigation techniques Micro irrigation: Appropriateness: Methods based on imported components Manufactured drip emitters and microsprayer assemblies are carefully supervised and maintained. Ancillary equipment such as screen and media filters, metering valves, pressure regulators and fertilizer injectors are used in various combinations. Note: These options will be justified only for cash crops in a stable market economy. From Small-scale irrigation for arid zones; Principles and options: http://www.fao.org/docrep/w3094e/w3094e00.htm

42. 42 B3.2.4Irrigation techniques Micro irrigation: Appropriateness: Methods based on imported materials but local fabrication Moulded plastic pipes or extruded plastic tubing are perforated manually and laid over the ground to simulate drip irrigation. Vertical sections of plastic pipes (or even discarded plastic containers such as bottles) are embedded in the ground. Thin-walled plastic vessels are filled with sand or gravel to provide mechanical resistance to crushing.

43. 43 B3.2.4Irrigation techniques Micro irrigation: Appropriateness: Methods based on imported materials but local fabrication Slit plastic sleeves cover the perforated sections of the tubes to prevent root penetration into the outlet holes. Sand filters prevent suspended particles or algae from clogging the outlets. Auxiliary containers are used to dissolve and inject fertilizer into the irrigation water. Vertical standpipes are used to deliver water from an underground pipe to small basins.

44. 44 B3.2.4Irrigation techniques Micro irrigation: Appropriateness: Methods based entirely on local materials and workmanship Low-fired porous ceramic pots are placed on the surface or embedded in the soil within the root zone. When filled with water and dissolved fertilizers, the permeable clay receptacles ooze water and nutrients into the soil. Sectioned ceramic pipes constitute line sources that feed elongated beds.

45. 45 B3.2.4Irrigation techniques Micro irrigation: Appropriateness: Clay pot method

46. 46 B3.2.4Irrigation techniques Modern irrigation technologies: Appropriateness (from Cornish) The technology must offer the farmer sufficient financial return or a reduction in labour demand, to justify the investment Farmers need to grow high value crops for an assured market in order to cover costs Increasing national or regional water shortage is an important factor motivating governments to promote the use of modern irrigation technologies

47. 47 B3.2.4Irrigation techniques Modern irrigation technologies: Appropriateness Governments must enact policies promoting the technologies for the smallholder, making it attractive to manufacturers and dealers to develop and promote them Suitable systems must be relatively cheap and straightforward to operate and maintain Farmers require effective technical support in the initial years – failure = ruin