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Irrigation Basics for Landscape Irrigation Contractors – LSU AgCenter 1 Sprinklers and Equipment Sprinklers and Equipment Dr. Ron Sheffield LSU Ag Center, Biological & Agricultural Engineering [email protected] Sprinkler Irrigation Sprinkler Irrigation y 4 types of sprinklers Spray Flood Flood Rotary Micro-Irrigation Flood Sprinklers Flood Sprinklers y High flow devices used to saturate soil where sprinkler application is not wanted y Usually installed below plant height (trees, shrubs, flower beds) (trees, shrubs, flower beds) y Concern over runoff or flooding y Most common version are for micro applications Spray Sprinklers Spray Sprinklers Fixed Angle Spray Nozzles Adjustable Angle Spray Nozzles Rotary “Impact” Sprinklers Rotary “Impact” Sprinklers Nursery Systems Gear Gear-Driven Rotary Sprinklers Driven Rotary Sprinklers Single Stream Rotator Multi-Stream Rotators

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Page 1: Sprinkler Irrigation Sprinklers and Equipment - LSU AgCenter · Irrigation Basics for Landscape Irrigation Contractors –LSU AgCenter 1 Sprinklers and Equipment Dr. Ron Sheffield

Irrigation Basics for Landscape Irrigation Contractors – LSU AgCenter

1

Sprinklers and EquipmentSprinklers and Equipment

Dr. Ron SheffieldLSU Ag Center, Biological & Agricultural [email protected]

Sprinkler IrrigationSprinkler Irrigation

4 types of sprinklers◦ Spray◦ Flood◦ Flood◦ Rotary◦ Micro-Irrigation

Flood SprinklersFlood Sprinklers

High flow devices used to saturate soil where sprinkler application is not wantedUsually installed below plant height ◦ (trees, shrubs, flower beds)(trees, shrubs, flower beds)

Concern over runoff or floodingMost common version are for micro applications

Spray SprinklersSpray Sprinklers

Fixed Angle Spray Nozzles

Adjustable Angle Spray Nozzles

Rotary “Impact” SprinklersRotary “Impact” Sprinklers

Nursery Systems

GearGear--Driven Rotary SprinklersDriven Rotary Sprinklers

Single Stream RotatorMulti-Stream Rotators

Page 2: Sprinkler Irrigation Sprinklers and Equipment - LSU AgCenter · Irrigation Basics for Landscape Irrigation Contractors –LSU AgCenter 1 Sprinklers and Equipment Dr. Ron Sheffield

Irrigation Basics for Landscape Irrigation Contractors – LSU AgCenter

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Drip/Micro IrrigationDrip/Micro IrrigationHighest equipment costs per area and usually highest water use efficiencyAllows for precise water management in small areasFacilitates daily or more yfrequent irrigation to reduce plant moisture stressLow pressure requirements (10-15 (psi) low flow rates (gph not gpm)

Impact Sprinklers on Risers Micro-Bubbler

Pop-up Rotator Micro-Spray

Using which? Where?Using which? Where?

Rotary◦ Large turf areas

Spray◦ Small lawn & planting bed areasSmall lawn & planting bed areas

Micro/Bubbler◦ Small planting beds, shrubs, trees

Sprinkler SpacingSprinkler Spacing

S

Sr

Square Spacing

S

SsTriangular Spacing

Compensating for WindCompensating for Wind

0 – 3 mph winds◦ Ss & Sr = Diam. * 0.55

4 – 7 mph winds◦ Ss & Sr = Diam. * 0.50

SSr

8+ mph winds◦ Ss & Sr = Diam. * 0.45

S

Ss

Gross Precipitation RateGross Precipitation Rate

AQPR = PR = Gross Precipitation Rate

Q = Flow; A = Area

396 Q

Theoretical precipitation rate; does not account for losses from sprinkler to soil

2

3.96

ft

gpm

hrin A

QPR

×=

Page 3: Sprinkler Irrigation Sprinklers and Equipment - LSU AgCenter · Irrigation Basics for Landscape Irrigation Contractors –LSU AgCenter 1 Sprinklers and Equipment Dr. Ron Sheffield

Irrigation Basics for Landscape Irrigation Contractors – LSU AgCenter

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Net Precipitation RateNet Precipitation Rate

unet At

VPR××

=66.3

Measure of the amount of water that reaches the soil; Gross Precipitation Rate minus losses from the sprinkler to the landscape

PR = Net Precipitation Rate (in/hr)Vu = Average catch volume for area (mm)t = testing time (minutes)A = Catch device throat area (in2)

cdAt ×

PR for Square SpacingPR for Square Spacing

Sr

Ss

QPR gpm×3.96

r

rSSPR

s

gp

hrin ×

=

PR for Triangular SpacingPR for Triangular Spacing

3.96 × gpmQPR

Ss866.02 ×

=s

gp

hrin S

PR

PR for Single Row of SprinklersPR for Single Row of Sprinklers

Ss

DiameterSQ

PRs

gpm

hrin 8.0

3.96×

×=

PR for Irregularly Shaped AreasPR for Irregularly Shaped Areas

Add up the gpm and estimate the total area being watered

2

3.96

ft

gpm

hrin A

QPR

×=

Changing sprinkler arcsChanging sprinkler arcs16 gpm @ 0.24 in/hr 16 gpm @ 0.48 in/hr

16 gpm @ 0.96 in/hr

16 gpm @ 0.32 in/hr

Page 4: Sprinkler Irrigation Sprinklers and Equipment - LSU AgCenter · Irrigation Basics for Landscape Irrigation Contractors –LSU AgCenter 1 Sprinklers and Equipment Dr. Ron Sheffield

Irrigation Basics for Landscape Irrigation Contractors – LSU AgCenter

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Matched Precipitation Rate (MPR)Matched Precipitation Rate (MPR) Matched Precipitation Rate (MPR)Matched Precipitation Rate (MPR)

Matched precipitation heads have flow rates that are proportional to the degree of arc◦ 8 gpm @ 3600gp @◦ 4 gpm @ 1800

◦ 2 gpm @ 900

◦ 1 gpm @ 450

Other EquipmentOther EquipmentIrrigation ControllersIrrigation Controllers

ProgrammableFlexableMuti-zoneManual modesManual modes24-volt

Single Station ControllersSingle Station Controllers

Battery operatedSingle zoneAdding new zonesFaucet or below Faucet or below ground

Rain SensorsRain Sensors

Conserves irrigation waterReduces over-irrigationWorks with all 24 VAC

llcontrollersInterrupts, doesn’t change irrigation programs. Automatically returns to normal watering.Most with adjustable rainfall shutoff amount

Page 5: Sprinkler Irrigation Sprinklers and Equipment - LSU AgCenter · Irrigation Basics for Landscape Irrigation Contractors –LSU AgCenter 1 Sprinklers and Equipment Dr. Ron Sheffield

Irrigation Basics for Landscape Irrigation Contractors – LSU AgCenter

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Operation of irrigation systemsOperation of irrigation systemsIrrigation Scheduling, Soil Moisture Based:Irrigation Scheduling, Soil Moisture Based:

• TDR (time domain reflectometry)• Relatively expensive – requires special instrumentation to

read sensors• Relatively easy to use and maintain• Affected by temperature (slightly, should read at the same

time on a daily basis)• Good life expectancy (will last many years if properly

maintained)• Can be integrated into a computer based operating system• Does a good job of integrating soil moisture conditions

across a range of depths, does not do a good job of indicating how deep water has penetrated the soil

• Readings are affected by ions in the soil water

Flow Check SensorsFlow Check Sensors

Reduced costs for rupture-related repairs“Overflow watchdog” provides constant update for any systemCustomized calibration for precise system control

ValvesValves

Controller and manual operationDesigned for specific flow, pressure, and water quality24 VACSome allow pressure regulators

Weather StationsWeather Stations

Can provide operational shut-offs◦ Wind◦ Rain

Single home or communityCalculate and compensate for changes in ET

Sprinklers and EquipmentSprinklers and Equipment

D R Sh ffi ldDr. Ron SheffieldLSU Ag Center, Biological & Agricultural [email protected]