irrigation basics-7:00-8:00 pm - cornell university

} Irrigation Basics-7:00-8:00 PM◦ Why water◦ Determining water use requirements◦ Design standards

} Break- 8:00-8:10 PM} How to utilize irrigation 8:10-9:00 PM◦ Components◦ How to water properly◦ Basic troubleshooting

1/20/2009Cornell Short Course


•Why water is important in Turf management

•How to water properly

•Identify key shortcomings in watering practices

•Basic Troubleshooting

1/20/2009 Cornell Short CourseThere is no new water.

"The wars of the next century will be about water."Ismail Serageldin, vice president of the World Bank


•Water use is doubling every 20 years

•Inland aquifers are being drawn down to below sea level

•Subsidence is over 30 feet in some areas

} Agronomics} Cultural} Aesthetics} Safety


}


} James Beard of Ohio State states “ The major reason landscape plantings do not survive is moisture, e.g., too little, too much, too often, or a combination

} Water stressed plants produce less foliage, and are more disease and insect susceptible


}



50 %Mineral

25 % Pore Space

25 % Water

} Fertilizers must be in solution

} Mechanical Turf practices such as aerification, de-thatching, and over-seeding are easier with “lubrication”

} Seasonal (summer) renovation (s) require water


} Proper soil composition ratios of soil/water/pore space provide a safer cushion

} G-max type tests such as those performed on synthetic turf can show higher numbers on non-irrigated, compacted soils than asphalt

} Pennsylvania study shows that 21% of injuries were field related

} Better cushioning adds to resiliency of turf; saving legs, ankles, and other joints


Table 2. Impact absorption values for high school athletic fields versus other surfaces (Rogers et al.,1988).

Impact hammer weightType of surface 0.5 kg 2.25 kg

------------------- gmax† ------------------

High school athletic fields 50-286‡ 33-167Artificial turf 109-172 60-91Frozen practice athletic field 404 303Tiled, concrete basement floor 1440 1280Carpet and pad on tiled concrete floor 260 190Carpet and pad on hardwood floor 86 134

† g max = maximum deceleration (harder surfaces have greater gmax values).‡ Good maintenance practices and field conditions generally were associated with lower

impact valuesthat indicated less hardness

Home lawn owners derive the benefits of both physical exercise and therapeutic


Table 1. Temperature comparisons of four types of surfaces on August 20 in College Station,TX.

Maximum Minimumdaytime nocturnalSurface surface

Type of surface temperature temperatureGreen growing Cyodon turf 31oC 24oCDry bare soil 39oC 26oCBrown summer-dormant Cynodon turf 52oC 27oCDry synthetic turf 70oC 29oC


(88 F)(102 F)(132 F)(158 F)

* From “The Role of Turfgrasses in Environmental Protection and Their Benefits to Humans” James Beard

} Based on ET (Evapotranspiration) per day measured in inches

} Area in acreage } 27,154 gallons/acre inch} Available water source (quantity, quality, and

pressure)


} Based on “Water Window”} Based on Soils} Based on Economics} According to seasonal ET averages over 30

years, approximately 300,000 gallons of supplemental water is required/ soccer field


} 27,154 gallons per acre inch} .20”/ hr. is safe, average precipitation rate for

most soils} 1 Inch of supplemental water during water

stress periods has been the historical, accepted norm for upstate New York


0

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May July Sept.

30 yr. avghighestlowest

inches

1/20/2009 Cornell Short Course

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May July Sept.

Avg/wkHighest lowest

*Application Rates based on weekly Et values x crop coefficient (.8)

.1 inch in deviation from average represents +/- 5400 Gallons/ week/ Soccer field in over or under watering fields



Water source

Pipe sizing

Equipment Selection

Hydraulics

Water window

Head placement

Pipe routing

Soil Conditions

Scheduling

} Velocity in irrigation systems to be below 5 fps

} Friction (pressure) losses based on four factors: Pipe size, length, smoothness, and volume

} Pressure losses also occur due to elevation change (.433 psi/ft), backflow devices, solenoid valves and fittings


} A water source provides 50 gpm at 75 psi. What size pipe should he or she use to travel 1000’, uphill 20’, and still keep 60 psi available for the sprinklers? How many heads w/ a #12 nozzle can be put on a zone?

Allowable loss= 15 psiElevation loss= 20 x .433= 8.66 psiFriction loss for 2 ½ pipe/ 100’=.57 x 10= 5.78.66 + 5.7= 14.36


} Soccer field complex with 5 fields (+/- 10 acres) wants to water between 2 AM and 7AM 3x per week. How much water per week in July? How many gallons/minute? What size mainline?

27,154 gal./acre in. x 10 acres = 271,540 gal./week271540/15 hours = 18,102 gal./hr.18,102/ 60 min. = 302 gpm.What pipe size do we need?


} Natural} Manual} Semi-automatic} Automatic


} Labor intensive} Constant monitoring} Water waste} Destructible} 40-90 locations for

soccer} 12 sprinklers and hoses

required to water during work week/ field

} $300-1200


} Less labor} Inefficient

watering} 2-3 field capacity} $ 7,500- 10,000


} Precise watering} Water savings} Labor savings} Various control levels} *$20,000.00 -$40,000

installed price

} *Variables such as field conditions, labor rates and water source effect installed prices


} Fingers of the system} Closed case rotors, sprays, impacts, stream rotors} Spray range from 4’ to over 200’


} Nerves of the system} Pressure rated to above

system operating pressure

} Some capable of dirty water applicalions


} Brains of the system} Range from small

“analog” on-off type to virtually limitless control with certain inputs

} Inputs can include sensors such as ET, Weather stations, solar clocks, soil moisture, pump controls, and more


} Arteries and neurons of the system

} Different types of materials for different engineering

} Must be sized properly


} Heart of the system} Many configurations;

Vertical Turbine, centrifugal, submersible

} VFD’s act as system “governor” for energy savings



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irrigation basics-7:00-8:00 pm - cornell university

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