Table Of Content

A project of Volunteers in Asia Palper No. 95 FAO Agricultural Development by: L. J. Booher Pub1 ished by: Food and Agricultum Organization of the United Nations Via delie Terme di Caracalla OOi80 Rome Italy Available from: UNIPUB 345 Park Avenue South New York, NY 10021 USA Reproduced by permission of the Food and Agriculture Organization of the United Ltions. Reproduction of this microfiche document in any form is subject to the same restrictions as those of the original document. Although only 15 to 20 percent of the world’s crop land is under irrigation, the production from irrigated land amounts to as much as 30 to 40 percent of total world agricultural output. The ueeded increase in food production will therefore depend to an appreciable extent on enlarging the area under irrigation and improv- ing existing systems. Surface systems of irrigation are the most widely practised. This publication is a com- prehensive survey of all the several existing surface systems. Their combination in one vol- ume makes possible the study and comparison of the various parameters of soil, water supply, topography and cropping possibilities of these systems, as well as their technical requirements, practical application and costs - knowledge of great value in the selection and planning of an irrigation scheme. The book is particularly recommended to students, planners and design- ers of farm irrigation systems, SURFACE IRRIGATION This is the last major contribution of L.3. Booher to the field of agricultural water management. Mr. Booher, who was recognized as a world authority on the subject. died on 22 November 1972. His absence will create a void in the dis- cipline which will not be easily filled. This is the last major contribution of L.J. Booher to the field of agricultural water management. Mr. Booher, who was recognized as a world authority on the subject, died on 22 November 1972. His absence will create a void in the dis- cipline which will not be easily filled. FAO Agricultural De velopnterl t Paper No 95 FAO Land and Water Deveiopmertt Series NO 3 SURFACE IRRIGATION b L.J. BOGHGR Consultant Land and Water Development Division, FAO Extension Irrigationist University of California, Davis FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS ROME 1974 First printittg I974 Second printing 1976 The copyright in this book is vested in the Food and Agriculture Organization of the United Nations. The book may not be reproduced, in whole or in part, by any method or process, without written permission from the copyright holder. Applications for such permission, with a statement of the purpose and extent of the reproduction desired, should be ad- dressed to the Director, Publications Division, Food and Agriculture Organization of the United Nations, Via delle Terme di Caracalla, Rome, Italy. @ FAO 1974 Printed itr Italy CONTENTS Introduction , . . . . . , . , , , , . . . . . . . . . . . . . . . . . . . , . . . . . . . . , . , 1 1. 2, 3. 4. Water supply ...................................... 3 Methods of water delivery ........................... 3 Water requirements ................................. 4 Small regulating reservoirs ............................ 7 Soils .......... . .................................. 10 Infiltration rates .................................... IO Water-holding capacities of soils ...................... I2 Land preparation ................................... I6 Soil survey ........................................ 16 Engineering ....................................... 17 Equipment ........................................ 22 Open distribution systems ............................ Unlined ditches ................................ :. .. Lined ditches ...................................... Flumes ........................................... Design of open distribution systems ................... Control structures for ditches .......................... Canal outlets .................................... Division boxes ................................. Checks ....................................... Drops ........................................ Other structures ................................ Inverted siphons ............................... Outlets.. ...................................... 31 32 34 39 41 44 44 46 46 49 50 51 52 V 5. Piped distribution systems . . . . . . . . . . . . . . . . . . . . . . . . S . . . Types of pipe ..................................... costs ............................................ Types of pipeline systems ............................ Friction losses ...................................... Control structures for pipelines ........................ Met gates ..................................... Flow-control gates and valves ..................... Air vents ...................................... Outlsts ........................................ Hydrants ..................................... Gated pipes ......... ......................... 6. Selecting the method of irrigation to use . . . . . . . . . . . . . . . . . 77 7. Basin irrigation ..................................... Relation of soil type to flow of water and area in each basin Slope in relation to size and shape of basin ............... Forming the levees .................................. Filling the basins with water .......................... 8. Border irrigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Soils ............................................. Slope ............................................ Width of border-strips ...... . ........................ Length of border-strips ............................... Stream size ........................................ Design criteria ..................................... Forming the levees .................................. Controlling the water ................................ 9. Wild flooding ...................................... Ditches ............. . ............................. Outlets ........................................... Water management ................................. 53 53 56 57 59 64 64 65 66 67 71 74 8G 81 85 86 89 93 95 97 97 98 99 103 104 108 109 110 110 vi ‘urrow irrigation ................................... Furrow and bed shapes .............................. Furrow spacing ..................................... Furrow slopes ...................................... Contour furrows .................................... Benched furrows .................................... Zigzag furrows ..................................... Furrow Iengths ..................................... Flow rates ......................................... Regulating the flow of water into furrows ............... Average depth of water applied ....................... Corrugation irrigation ................................ Soils ............................................. Land preparation ................................... Slope ............................................ Length of runs ..................................... Forming the corrugations ............................. Flow of water in corrugations ......................... Drip irrigation ...................................... Requirements of drip systems .......................... LJses of drip irrigation ............................... Dangers from salt accumulation in the soil .............. Types of emitters ................................... Performance of emitters .............................. Plugging of emitters ................................. Supply lines ....................................... Care in using plastic materials ......................... 11. 12. Conversion factors ...................................... References ............................................ 111 111 114 115 117 117 120 121 123 126 130 133 133 134 134 I35 135 137 140 140 141 143 I43 145 149 150 152 154 157 vii LIST OF ILLWSTRATIONS 1. Distributor and Neyrpic automatic gate ............... 2. Soil moisture characteristics ........................... 3. Topographic map for land grading .................... 4. Profiles of average slopirs ............................ 5. Scarifier. or subsoiler. mounted on wheel assembly ....... 6. Chisels to lo~scn soil jr break up shallow compacted layers. . 7A-7B. Buck :Leaper and rake . . . . . . . . . . . . . . . . . . . . . -. . -. . 8. 9. 10. Il. 12. 13. 14. 15. 16. 17. 18. 19. Buck scraper drawn by team of horses . . . . . . . . . . . . . . - . . . Small hydraulic scraper operated with a 45-to-SO-horsepower wheel tractor . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Small two-wheel scraper used with four-wheel tractor . . . . Rotary-type earth scraper operated with 40-to-60-horsepower wheel tractor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Elevating scraper with two-wheel tractor for land grading . . Four-wheel rubber-tired tractor and two-wheel bucket scraper pushed by crawler tractor with blade during loading operation Crawler tractor and four-wheel bucket scraper for land grading Wooden float . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bottomless scraper for final smoothing . . . . . . . . . . . . . . . . . . Another type of bottomless scraper . . . . . . . . , . . . . . . . . . . . . Earthen ditch distributing irrigation water . . . I . . . . . . . . . . Homemade drag-type ditcher . . . . . . . . . . . . . . . . . . . . . . . . . 5 13 18 19 23 23 24 25 25 27 27 27 28 28 29 30 30 33 33 20. V-ditcher mounted on tool bar of crawler tractor ~ *. D . “. 21. Concrete lining in elevated ditch . . . . , . . . . . . . . . . . . ~ I - ” _ . 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39, 40. 41. 42. 43. x Precast concrete blocks lining field ditch . I.. . . . . . . . . . . . . Precast concrete flumes mounted on pedestals . . . . ~. ~. . . . Cross-section of canal . . . . , . . . . . . . . , . . . . . . . . m - e - a - e s e . Control gate made of precast concrete blocks, in unlined canal................................................. Underflow control gates set in concrete headwall . , . . ~ Constant-upstream-level Neyrpic automatic + , . m . . . . Wooden checks in earthen ditch . . . . . . . . . . . . . Concrete check gate in earthen ditch . . . . . . . . . . . . . . . . . . . Concrete check dam in earthen dir-b . . . . . . . . . . . . . . . . . . Portable canvas dam in earthc:; . . ! . . . . . . . . . . . . . . . . . . Pipe drop structure for field ditches . . . . . . . . . . . . . . . . . . . . Cross-section of inverted siphon placed under roadway . . . Workman installing precast concrete pipe in trench . . . . . . . Cast-in-place concrete pipeline being constructed in trench . . Profile of overflow stands with baffles, used with open pipeline system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Automatic float-controlled valve in pipe stand . . . . . . . . . . . Slide gate in standpipe to regulate flow in pipeline . . . . . . . . Line-gate valve for concrete pipeline . . . . . . . . . . . . . . . . . . . Cross-section of concrete supply pipe and riser with alfalfa valve attached . , . . . - . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Orchard valve and low-pressure open hydrant with slide gates for controlling flow to furrows . . . . . . . . . . . . . . . . . . . Water from buried concrete pipeline being released through capped riser outlets . . . . . . . . . . . . . . . . . . . . . . . . ._.. . . . . . . . . Portable metal hydrants . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . 34 35 38 4u 43 45 4s 47 47 48 48 49 50 51 54 55 58 58 66 66 70 70 73 73 44. Aluminium pipe ,. :th slide gates I . . . . . . . . . . . . . _ . . . . I _ _ . 45. Aerial view of contour basins .......................... 46. Small basins irrigating young date palms ............... 47. View of small basins irrigating crops grown under date palms 48. Citrus trees irrigated with basins ....................... 49. Levees constructed on lines of equal elevation to form contour basins ............................................... 50. Large contour basins and rectangular basins irrigating rice. s 51. Earth levee between rice paddies ....................... 52. Wooden A-frame ridger for forming levees .............. 53. Large V-diker ......................................... 54. Precast concrete units forming levees ................... 55. Control gate in place in rice levee ...................... 56. Wooden gate with flashboards ........................ 51. Water being released into border-strips ............... 58. Deciduous orchard irrigated by border-strips ............ 59. Metal A-frame ridger and shaper for forming flat-sided levees 60. Drag float smoothing land surface between levees ........ 61. Weir-type outlet with flashboards in concrete-lined canal . . 62. Circular gate on pipe outlet from concrete-lined canal .... 63. Grade ditches across field to be irrigated by wild flooding . . 64. Furrows irrigating tomato plants on raised beds ......... 65. Broad furrows in orchard ............................ 66. Young melon plants on sloped beds to control salts and receive more sunlight ................................. 67. Furrows placed on diagonal of field to reduce slope ...... 68. Wooden flume conveying water down slope ............. 69. Contour furrows irrigated from wooden flume ........... 75 82 82 83 85 87 88 89 90 90 9 1 92 94 94 104 104 105 105 109 113 113 114 116 118 118 xi