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Drip Irrigation System Layout & Design. ADVANTAGES. Water savings Crop response Labour savings Fertilizer savings Less weed growth. Drip Irrigation System Layout & Design. ADVANTAGES. Saving in pesticides Possible use of saline water Early maturation
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ADVANTAGES • Water savings • Crop response • Labour savings • Fertilizer savings • Less weed growth Drip Irrigation System Layout & Design
ADVANTAGES • Saving in pesticides • Possible use of saline water • Early maturation • Minimum soil crusting • Field edge loss reduction Drip Irrigation System Layout & Design
ADVANTAGES • Improved root penetration • Irrigation of low intake soils • Easy field operation Drip Irrigation System Layout & Design
LIMITATIONS • Sensitivity to clogging • Salinity hazards • Moisture distribution problems • High initial cost • Dry soil & dust formation Drip Irrigation System Layout & Design
LIMITATIONS • High skill required for • Design • Installation • Operation • Maintenance Drip Irrigation System Layout & Design
SYSTEM COMPONENTS DISCHARGE ELEMENTS (EMITTERS) • Selection criteria • General suitability • Pressure flow characteristics • Manufacturing variability Drip Irrigation System Layout & Design
SYSTEM COMPONENTS • Sensitivity to temperature • Resistance to clogging • Cost • Risk Drip Irrigation System Layout & Design
SYSTEM COMPONENTS Types - Orifice emitter q = C A - Tube emitter q = 0.034 h.78 - Labyrinth emitter q = 0.125 h.78 Drip Irrigation System Layout & Design
SYSTEM COMPONENTS (Contd.) • Lateral lines • Sub – mains • Main lines • Mani – folds • Filters Drip Irrigation System Layout & Design SYSTEM COMPONENTS
PROBLEMS IN FILTRATION • Physical contamination • Chemical contamination • Effect of water source • Fitness of filtration Drip Irrigation System Layout & Design
FILTERING EQUIPMENT & METHODS • Pressure regulators • Control valves • Misc. fittings Drip Irrigation System Layout & Design
DESIGN Amount of water to apply q = C U . A. σc qm = Where : qm is av. Emitter discharge in lph H is total hr. of operation/day N is nos. of emitters/ plant q = C U . SI . Sm. σc Drip Irrigation System Layout & Design
DESIGN • Spacing of emitters Radius of coverage R = Max. spacing Sl X Sm Drip Irrigation System Layout & Design
DESIGN • Uniformity of water distribution Flow variation < 20% Pressure variation < 20% Drip Irrigation System Layout & Design
DESIGN • Lateral & mainlines Hazen William iq. H = 15.25 X L H = 5.35 (In decreasing flow lines) Drip Irrigation System Layout & Design
DESIGN CHARTS • Lateral for uniform slopes • Lateral for non-uniform slopes • Sub-main • Main Drip Irrigation System Layout & Design
Example 1 GIVEN : L = 50 m H = 10 m S = 1% Emitter spacing = 0.3 m q = 4 lph / emitter Drip Irrigation System Layout & Design
Example 1 FIND: Lateral dia. L/H = 5 Q = 4 X 150 = 600 lph = 0.167 lps FIG. 6 (a) 12 mm is acceptable Drip Irrigation System Layout & Design
Example 2 GIVEN: L = 120 m Dia = 16 mm H = 10 m Q = 0.13 lps Drip Irrigation System Layout & Design
Example 2 SLOPE: 0 – 30 3% down 30 – 60 2% down 60 – 90 0% 90 – 120 3% down Drip Irrigation System Layout & Design
Example 2 SOLUTION: I/L HI (m) HI/ L 0.25 0.9 0.0075 0.5 1.5 0.0125 0.75 1.5 0.0125 1 2.4 0.02 Drip Irrigation System Layout & Design
Example 2 Plot I/L vs. HI/ L OHP 12 H = 5.35 X L = Drip Irrigation System Layout & Design
Example 2 = 1.5 m = = .15 L/H = 120/10 = 12 Drip Irrigation System Layout & Design
Example 2 Check pressure variation at 4 points at I/L 0.25, 0.5, 0.75, 1. Fig 8 Variations are (QD III) Less than 10% Drip Irrigation System Layout & Design
Example 3 GIVEN: A= 20 ha Fig 11 Subplot = 0.4 ha Q = 2 lps / subplot Drip Irrigation System Layout & Design
Example 3 Fig 12, Plot mainline profile Plot reqd. pressure head Plot energy line Use Fig 10 OHP 14 with S = 1 % Find dia of mainline Table 5 Drip Irrigation System Layout & Design
