AGSC 201 Chapter Irrigation, Spring 2016

Irrigation Systems Hadi Jaafar, Ph.D. Department of Agriculture FAFS AUB Spring2015 Outline What is irrigation Why it is needed When it is needed How much is needed Where to get the water from? How to apply the water? What is irrigation Storing Water Diverting Water Spreading Water (Applying Water to Plant Roots) Consuming Water Returning/Draining water Why is it needed? Plants need water for photosynthesis (Transpire) Water evaporated from soil Sun Energy evaporates water Rainfall in summer is not enough When it is needed When soil moisture drops To a level where it might be hard for plants to extract it When rainfall is not enough Other times Where to get the water from? Surface • Rivers, Streams, Creeks • Lakes • Springs • Reservoirs Underground • Shallow Wells • Deep Wells Surface Water : Rivers and Dams Conveyance Systems: Canals Conveyance Systems: Pumps and Pipes Irrigation Methods • By Gravity (elevation difference .i.e slope) – Surface – Sub-irrigation (using water table)-uncommon • Pressurized, requires energy /Pumps or elevation difference – Sprinkle (higher pressure) – Drip (lower pressure) • Egypt (1840) Surface Irrigation • More than 80% of total irrigated areas in the world • Types: – Flooding (6000 years old – Rice, China) – Furrows – Basins – Borders Basin Irrigation Basin Irrigation Furrow Irrigation Furrow irrigation with siphons from earthen canal Furrow Irrigation Furrow Irrigation Border Irrigation Border Irrigation PRESSURIZED Sprinkle and Trickle 1. Stationary or solid-set for orchards and perennial crops 2. Semi-portable or hand-moved with fixed main lines and movable laterals 3. Low pressure under-tree sprinklers in orchards Types of Sprinkle Irrigation 4. High pressure for field crops or over-tree 5. Center pivot 6. Linear move Types of Sprinkle Irrigation Portable Sprinklers Center-Pivot types: 1. Stationary or solid-set • for orchards and perennial crops 2. SEMI-PORTABLE OR HAND-MOVED WITH FIXED MAIN LINES AND MOVABLE ATERALS 3. Portable • For crop germination or for irrigation supplemental to rainfall • For field crops or over-tree, Types: 5. High pressure such as big gun sprinklers TYPES: 5. CENTER PIVOT TYPES: 6. LINEAR MOVE Linear Move Sprinkle Irrigation Sub-Irrigation • Controlling shallow groundwater • Needs a water table close to plants root zone • Not widely used 2/2/2015 Drip Irrigation Drip or Trickle Irrigation Surface applicators • Emitters • Micro-sprayers/Micro- sprinklers • Bubblers • Misters Sub-surface applicators • Point source emitters • Line source emitter tubing and tapes 2/2/2015 Micro-irrigation Systems: Methods 2/2/2015 Typical System Layout 2/2/2015 Typical Drip System Layout 2/2/2015 Subsurface Drip Irrigation • Low Pressure: < 5 psi or 3 m of head • Small diameter tube delivers the water • For Orchards, landscaping, ornamentals Basin Bubbler 2/2/2015 Other Types Precision Irrigation