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Drip Irrigation How and Why? Presented By

Val J. Tancredi Stettler Supply Company, Salem

What is Drip Irrigation? 

Low Volume/Low pressure method of applying water and nutrients at high frequency directly into the root zone of a plant. Water moves through soil pore space by capillary action and gravity. Pioneered in England 1940’s, perfected in Israel, introduced to USA in early 1960’s. 1970 here in Willamette Valley.

Types of Micro-Irrigation Long Term (20 yrs) Heavy Wall Emitterline  On-line Emitter installed on Tubing  In-line Emitter installed in the Tubing  Micro-Spray or Micro-Sprinklers $$ Short Term (1-2 yrs) Thin Wall 5-15 mil. TAPE  Must be protected against Physical Damage  Higher filtration requirement than emitters

Water Movement in Soil Gravitational Water Movement saturation-free water, de-oxygenation  Percolation-Leaching  Hygroscopic Water, Adhesion & Cohesion Capillary Action  High Frequency = Pulsation 

Capillary Action

Emitters spaced so the wetting patterns overlap and support the crop feeder roots

A System Approach 

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Modern Irrigation too important to be bought as “parts” - should be viewed as a production tool & purchased as a system. Meet Crop Water Requirements, Daily High Application Uniformity, > 90-95% Efficient & Reliability with Economy O & M Training and Warranty

Wide Row Hops, Well Water ď Ž

Hops with Surface Water

Drip in Vines

Caneberry-Dripline on wire

Visually Confirm Operation Less Rodent/Coyote Problems

Warmer Soil, Fewer Weeds, Dry Roadways

Support Cover Crop

Conduct Cultural Practices while you Irrigate

Drip System Mechanics 

Single Emitterline down each row on ground or wire Emitter Spacing & Flow Rate based on Soil Type, Desired Application Rate Tubing Diameter based on Length of Run


Drip System Mechanics BLUE BERRIES

<.5 GPH (4 L/H) Emitter at < 18” o.c.  Double Emitterline down each row  Stagger emitters to cover bed  Bungee cord tension to keep tube on hill 

Blueberries on Raised Bed

Start Plants on Single Line Possible

New Planting

First Year Response

No Translocation = Two lines

Keep Dripperline on Top of Bed

Bungee Cord Tensioner

End Of Tubing

Drip System Components     

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Emitterlines and Fittings with screen washers PVC Sub-mains with Flush Valves PVC Saddles with Flex Hose Risers, Ball Valves Pressure Regulating Control Valves Filter Stations with Chemigation Check Valves Automatic Controllers Water Management tools

Injector Pump

Manual Screen Filter Station Fertilizer Tank ButterFly Valve

Manual Screen

Pressure Relief Valve


Chemigation Check Valve

Inject Agro-Chemicals Evenly

System Approach Results in Accuracy and Permanent Record

Isolation and Control Valves

Use Water Tight Wire Connectors

Block Regulator

Gauge to Confirm Required Pressure

Ball Valve Flush & Drain Installed below Ground to avoid Tractor Blight

Note PVC Flex Hose Riser on Submain

Riser Assembly Wye

Hose Fittings Connected to Submain by PVC Flexible Hose to Avoid Breakage

Double Dripperline Tubing

Tubing Installed After Crop Planting

Operational Considerations 

Operated frequently enough to meet crop water requirement to avoid soil cracking. Drip Water can’t cross crack. (Sawdust) Lower application rates mean no catch-up capacity, operate daily. Pulsation (multiple applications per day) demands system automation.

Monitoring the System 

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Like Checking the Oil in the Tractor – Drip Systems need Regular Maintenance Establish Flushing Schedule for Filters, Submains, and Emitterline Ensure Proper Operating Pressure Monitor Soil Moisture & Adjust Run Time Watch for and Treat for Bacterial Slime

Automatic Disc-Kleen Filter

Pressure Gauges on Inlet and Discharge Indicate when the Filter is Dirty and Requires Flushing

Flow Meters Management Tools

Note Straight Pipe, generally 10 up and 5 downstream pipe diameters

Water Quality Issues Wells-Groundwater  Water Test for Physical & Chemical Sand  Cl, Mn, Fe & Iron Bacteria Sand use Separator and Screen Filter 

Surface Water, P + C + Organic 

Self-Cleaning Screen or Disc or Media

Chemigation Check, Separator-Screen Constant Air/Vacuum Relief Vent

Automatice Flush Valves to Waste


The Secret to Production is the Fertilizer injected into the Water

Separator with Screen

Larger Separator for Higher Flowrate

Sand Media Filter Station

Automated Disc Filters

Self-Cleaning Screen Filter

Drip Advantages Production & Efficiencies  

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Precise Application/Uniformity of H2O & Nutrients Dry Roadways and Beds = Less Weeds Dry Foliage = Less Disease, Warmer Soil Higher Ratio of Soil Oxygen = Better Growth High H2O Efficiency and Lower HP Reqrm’ts Even Moisture content through Daily Cycles Even Growth, Crops Ripen More Evenly Undisturbed Cultural Practices = Spray and Harvest during Irrigation

Drip Disadvantages    

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Management Requirements Higher, Different Water Not as Visible as Sprinkler System Filtration of Source H20 a Necessary Expense Chemical Control of Bacterial Slime required Rodent, Insect, Equipment Damage a Problem Tape Disposal/Recycle can be a Problem

Even Growth!

Drip Irrigation of Blueberries

Work Field while Irrigating

Economics of Drip on Blueberries Lower Start-up costs: 


Solid Set OverHead Sprinkler Materials: $2,400 Acre Installation: $3,000 Acre Double Drip on Blueberries, less for Single Cane Materials: $2200 Acre Installation: $1,000 Acre

Put Drip to Work for You!

Thank You for Your Attention !