Irrigation

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Irrigation
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Water and Irrigation

• IMPORTANT ISSUES WATER QUALITY AND QUANTITY 
• CONSERVATION
• TURFGRASS AND WATER
• GRASS PLANT IS 80 TO 95 WATER
• AT 60 H20 THE PLANT DIES 

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Water and Irrigation

• TURGIDITY ______________________________________
  __________________________________________ 
• TRANSPIRATION RATE DEPENDS UPON ATMOSPHERIC
  CONDITIONS
• TRANSPIRATION RATES ALSO VARY WITH TURF SPECIES
  AND CULTIVAR

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Turfgrass Water Needs

• AN ACRE TURFGRASS CAN LOSE IN EXCESS OF 10,000
  GALLONS OF WATER TO THE ATMOSPHERE DAILY
• HOT, SUNNY, DRY, WINDY CONDITIONS
• TURFGRASS NEEDS 60 TO 70 GALLONS OF WATER TO
  PRODUCE 1 POUND OF DRY MATTER

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Water Relations in Turfgrass

• WHEN TRANSPIRATION LOSSES EXCEED ROOT ABSORPTION
  THE FOLLOWING MAY HAPPEN

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Water Relations in Turfgrass

• LESS _____________________
• REDUCED SHOOT ELONGATION
• DECREASED TURGIDITY AND SUCCULENCE
• METABOLIC PROCESSES BECOME SLOWER

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Water Relations in Turfgrass

• SYMPTOMS OF DROUGHT STRESS IN TURFGRASS
• LEAVES ________________________________
• (OVERERHEATED, WEAK OR DAMAGED ROOT SYSTEMS, LACK
  OFWATER)
• --
• NEVER MOW, AERIFY, FERTILIZE OR DO ANYTHING TO
  TURF IN DROUGHT STRESS!
•  

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Soil And Water

•  INFILTRATION RATE THE SPEED AT WHICH A SOIL
  CAN ABSORB WATER
• INFILTRATION RATE RANGES FROM 0.1 INCH/HOUR IN
  CLAY SOILS TO AS MORE THAN 3 INCHES/ HOUR IN
  SANDY SOILS
•  

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Soil And Water

• COMPACTION
• RESULTS IN THE LOSS OF MACROPORES (Soil
  structure)
• A CONSIDERABLE DECREASE IN THE INFILTRATION RATE
  OCCURS
•  

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Soil And Water

• PERCOLATION THE MOVEMENT OF WATER DOWN THROUGH
  A SOIL
• SANDY LOAM SOIL 2 FEET IN 30 MINUTES
• CLAY LOAM 2 FEET IN 4 HOURS 

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Soil And Water

• SANDY SOIL

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Soil And Water

• CLAY SOILS

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TERMS TO KEEP IN MIND

• FIELD CAPACITY
•  
• PERMENANT WILTING POINT
• AVALIABLE WATER

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From http//cru.cahe.wsu.edu/CEPublications/pnw04
75/pnw0475.html
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TERMS TO KEEP IN MIND

• ADHESION THE ATTRACTION BETWEEN WATER MOLECULES
  AND THE SURFACE OF SOIL
  PARTICLES

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TERMS TO KEEP IN MIND

• COHESION THE ATTRACTION BETWEEN MOLECULES OF
  WATER
•  
• EVAPOTRANSPIRATION

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Irrigation

• FACTORS WHICH INFLUENCE THE AMOUNT AND FREQUENCY
  OF IRRIGATION WATER REQUIRED ARE
• GRASS SPECIES AND CULTIVARS 
• SOIL TYPE 
• LEVEL OF MAINTENANCE

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Irrigation

• PRECIPITATION AMOUNT AND FREQUENCY
• WEATHER CONDITIONS
• HUMIDITY, WIND AND TEMPERATURE

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Determining When Grass Needs Water And
Application Rates

• WATER WHEN SYMPTOMS OF MOISTURE STRESS APPEAR
• COLOR OF TURF---BLUE-GREEN OR GRAYISH GREEN
• TRACKING REMAINS-FOOTPRINTS OR MACHINERY TRACKS
• SOIL EXAMINATION----
• KNIFE OR SOIL PROBE
• TENSIOMETER

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Fromhttp//lieth.ucdavis.edu/Research/tens/97/Te
nsiometer- pull of water moves gauge
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Determining When Grass Needs Water And
Application Rates

• MOISTURE METERS WHICH MEASURE ELECTRICAL
  RESISTANCE BETWEEN ELECTRODES
• http//www.sowacs.com/sensors/gypsum.html
• NEAR INFRA RED REFLECTANCE
• http//www.sensortech.com/main_pages/moisture/infr
  ared.htm
• TIME DOMAIN REFLECTOMETRY
• http//www.sowacs.com/sensors/tdr.html

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Determining Turfgrass Water Needs

• EVAPORATION PANS IN A SUNNY LOCATION

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Determining When Grass Needs Water And
Application Rates

• ESTIMATE OF THE EVAPOTRANSPIRATION
• http//ag.arizona.edu/azmet/et1.htm
• COOL SEASON TURF GENERALLY REQUIRES ABOUT
• _________________________________________________
  _______________________________
• http//www.soils.wisc.edu/wimnext/water.html

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• How should irrigation be applied?
• A ___________ IRRIGATION APPLIED IN
  __________________ TO AVOID RUN OFF ONCE OR TWICE
  A WEEK
• BEST IN SOILS WITH ADEQUATE WATER HOLDING
  CAPACITY AND DEEPLY ROOTED TURFGRASS

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• SANDY SOILS SHOULD BE IRRIGATED AT LEAST TWICE A
  WEEK, OFTEN DAILY WHEN ET IS HIGH-
• SAND ONLY HOLDS ABOUT 0.1 OF WATER/ INCH OF
  SOIL!

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• DAILY WATERING IS NOT USUALLY RECOMMENDED---SHALLO
  W ROOTING OFTEN RESULTS.
• However, on sandy soils daily irrigation is often
  required through warm dry periods.

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• If site specific ET data isnt available,
  irrigation to replacement of 75-80 of open pan
  evaporation is usually adequate for most cool
  season turf.

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Determining Irrigation Needs

• PROPER AMOUNT OF WATER IS THE SOIL WET TO A
  DEPTH JUST BELOW THE MAJORITY OF THE ROOT SYSTEM
  ?
• THIS IS USUALLY 4 TO 6 INCHES
• PLACEMENT OF CONTAINERS TO COLLECT WATER FROM
  SPRINKLERS----DETERMINATION OF PRECIPITATION RATE
• http//www.bae.ncsu.edu/programs/extension/publica
  t/wqwm/ag508_6.html

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Time of Day to Irrigate

• BEST TIME
• NIGHT----DISEASE PROBLEMS MAY DEVELOP IF THE
  GRASS IS DAMP OVERNIGHT (LWD)

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Other Water Application

• SYRINGING LIGHT WATERING LASTING NO LONGER THAN
  A FEW MINUTES
• GENERALLY DONT WANT TO __________________________
  ____________
• BEST PERFORMED EARLY AFTERNOON MOST USED ON
  GOLF COURSE TURF 
•  

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Some Basics of Sprinkler Irrigation

• Length of irrigation cycle is dependent on soil
  type.
• Generally, ___________________________ are more
  effective than one long cycle.
• Many sprinkler types are available to homeowners.
  (soaker hoses, oscillating, impact, etc)

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Some Basics of Sprinkler Irrigation

• Average precipitation rate with average water
  pressure is around 0.5 per hour. Test
• The more hose you put out, the greater the
  pressure loss so you must increase watering time
  in areas where more hose is needed to reach
  sprinkler.

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Some Basics of Sprinkler Irrigation

• Precipitation rate at the edge of the pattern is
  generally ________________________________ for
  most types of sprinklers.
• Wind greatly effects distribution pattern of all
  above ground sprinkler systems.

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Some Basics of Sprinkler Irrigation

• In ground systems should be designed with
  ________________________________to assure even
  distribution of water.

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Head to head coverage
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Some Basics of Sprinkler Irrigation

• http//www.rainbird.com/
• http//www.toro.com/landscape/irrigation/index.htm
  l
• http//www.arrosage.com/
• http//jessstryker.com/

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Effective Coverage and Coefficient of Uniformity

• Older impact type sprinklers actually have about
  the ___________________________, however these
  heads are rarely used anymore.
• Rotor driven sprinklers are the most commonly
  used sprinklers, especially on large sites.
  Rotor driven sprinklers also have a
  ________________________________________
• Pop up fixed spray heads generally have a lower
  ________________________________________.
  However, they are still commonly used on many
  residential sites due to their low cost.

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Fixed spray head performance.
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