verification of turfgrass evapotranspiration

Verification of Turfgrass Evapotranspiration in Utah

Prepared by Robert W. Hill and J. Burdette Barker

VERIFICATIONOFTURFGRASSEVAPOTRANSPIRATION

INUTAH

FinalReport

PerformancePeriodJuly18,2001–June30,2008

Submittedto

UtahDepartmentofNaturalResourcesDivisionofWaterResources

UtahAgriculturalExperimentStation StateofUtahProjectNo.797/789 ContractNo.01‐1995UtahStateUniversityControlNo.01‐1294

Preparedby

RobertW.HillandJ.BurdetteBarker

ProfessorandExtensionIrrigationSpecialistandStudentAssistantBiologicalandIrrigationEngineering

UtahStateUniversityLogan,Utah84322‐4105

Mentionofatrademarknameorproprietaryproductdoesnotconstitute

endorsementbyUSUanddoesnotimplyitsapprovaltotheexclusionofotherproductsthatmayalsobesuitable

UtahAgriculturalExperimentStationResearchReport#211

July8,2010

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EXECUTIVESUMMARYVerificationofturfgrassconsumptiveusewasaccomplishedwithfieldstudiesgenerallyduring2002‐2008infourareasofUtah:CacheValley(LoganGolfandCountryClub),SaltLakeCounty(MurrayParkwayGolfCourse),UtahCounty(BrighamYoungUniversity[BYU]SpanishForkFarm2002‐06)andWashingtonCounty(SunbrookGolfCourse,2002‐06andSouthgateGolfCourse,2004‐08).TwolysimeterswereinstalledateachofthethreesitesoutsideCacheValleyinlate2001andearly2002.TheexistingtwolysimetersinLogancontinuedtobeused.InApril2004athirdlysimeterwasinstalledatLoganandtwolysimeterswereinstalledatSouthgateGolfCourseinSt.George.Irrigationandrainaswellasdrainageweremeasuredateachlysimeteratintervalsduringthegrowingseason.Wateruseoftheturfgrasswassetequaltothedifferencebetweenmeasuredirrigationandrainfallandtheamountofdrainagewater.WeatherdataforusewithaPenmancombinationtypeETequationwascollectedwithelectronicweatherstations(CampbellScientific,Inc.)ateachsite.Cropcoefficientswerecalculatedastheratioofturfgrasswaterusetoalfalfareferenceevapotranspiration(ETr)calculatedwiththeASCEStandardizedPenman‐MonteithETequation(denotedasETrs).Observedseasonalturfgrassconsumptiveusevariedfrom11.2inches(LoganWest,2004,)to50.0inches(Southgate,2007).TherangeatLoganwas11.2(West,2004)to35.2inches(new,2007);atMurray,22.2(East2008)to30.5inches(East2005);atSouthgate,19.7(East2006)to50.0inches(West2007);atSpanishFork),14.2(South2002)to30.4inches(North2004)and13.0(East2004)to35.5inches(West2002)atSunbrook.DirectcomparisonofsuchvariationinETvaluesacrossyearsandsitesisproblematicduetodifferinggrowingseasonlengthsfromyeartoyear,siteenvironmentalconditions(averagetemperaturesandwindpatterns),andelevation(rangeof2600to4800ftabovemsl)fromsouthtonorthinUtah(latituderangeof37°Nto42°N).Themulti‐yearaverageseasonalobserved(basedonlyonindividuallysimeterET)cropcoefficientvaluesvariedfrom0.34(LoganWest)to0.65(SouthgateWest).StudyperiodaverageseasonalKcvaluesbylysimeterwere:Logan0.59(new),0.42(east),0.34(west)andsiteaverageof0.45;Murray0.57(botheastandwest)andsiteaverageof0.57;Southgate0.53(east),0.65(west)andsiteaverageof0.59;SpanishFork0.58(north),0.54(south)andsiteaverageof0.56andSunbrook0.49(east),0.46(west)andsiteaverageof0.47.AveragetwolysimeterseasonalKcvaluesatMurrayandSpanishForkweresimilar(0.57and0.56,respectively)althoughtherewaslessacrossyearvariationatSpanishFork.Analfalfareference(ETr)basedseasonalaveragecropcoefficient,Kcr,valueofabout0.60reasonablyrepresentsawellwateredturfgrass,cuttingheightof1.5to2inches,inthecentralandnorthernpartsofthestate,whereasaKcrof0.65wouldsimilarlybereasonabletouseinthelowerelevationandwarmersouthernUtah’sDixie.TheseKcrvalues,0.60and0.65,are,respectively,about7%and16%higherthantheKcrof0.56usedinearlierestimatesofturfgrassevapotranspirationacrossUtah(Hill,1994).

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MonthlyKcr,andsubsequentlygrassreferencebasedKco,valueswerederivedforfourofthelysimeters:Logan–new,SpanishFork–north,andbothSouthgatelysimetersbyproratingobservedlysimeterETbetweenadjacentmonthsusingthenumberofdaysinthemeasurementinterval.FurtherdataadjustmentsweremadeuponfinalanalysisbydiscardingobviousoutliersfromtheaveragemonthlyKcvalues.Themonthlycropcoefficient,Kcr,forthehigherelevationnorthernmajorityofUtahbeginswithavalueof0.45startingatturfgreenupandremainsat0.45forabout20daysuntiltheturfbeginsactivegrowth.TheKcrvaluethenincreaseslinearlyoverabout30daystoavalueof0.60whentheturfreachesfullandgrowth.TheturfKcrremainsat0.60forthedurationoftheseasonuntilcoolfalltemperaturesresultinreducedturfgrowthrates.Thisistypicallyaroundmid‐October,afterwhichKcrdecreaseslinearlytoward0.45inearlyNovemberandremainsatthatvalueuntildormancy.ThemonthlyKcrcurveforlowerelevationsouthernUtahissimilar;however,itcontinuesforthefullyearbeginninginJanuaryatavalueof0.50duringthesemi‐dormantperiod.InlateFebruarytoearlyMarchtheKcrvaluebeginstoincreaselinearlyovera30dayperiodtoavalueof0.65,andremainsat0.65forthemajorityoftheseasonuntilthegrowthslowsinmidtolateOctober.TheKcrvaluethendecreaseslinearlytoavalueof0.50,typicallyreachedinmidNovemberandremainsat0.50untilthefollowingspring.Inbothsetsofsuggestedcropcoefficientcurves,maintainingthemid‐seasonKcrataconstantvalue,0.60or0.65,ignorestheindicationofa“summerslump”inturfwateruse.Grassreferencebasedcropcoefficient,Kco,valueswerederivedfromKcrbymultiplyingKcrbyabout1.2.Thus,mid‐seasonKcovaluesof0.70fornorthernUtahandhigherelevationsand0.80forsouthernUtahandlowerelevationswereobtainedbyroundingtothenearest0.05.CorrespondingearlyandlateseasonKcovaluesare0.50and0.60,respectively,fornorthernhigherelevationandsouthernlowerelevationUtah.

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ACKNOWLEDGEMENTS

TheworkdescribedhereinwasperformedunderacontractbetweentheUtahDepartmentofNaturalResources,DivisionofWaterResourcesandUtahStateUniversity(DepartmentofBiologicalandIrrigationEngineering[BIE]).ThiscontractwasinitiatedinJuly2001toperformfieldresearchusinglysimetersatselectedUtahlocationstoverifypreviouslyusedconsumptiveuse(evapotranspiration)factorsforturfgrass.ThecontractwasoriginallyexpectedtoendJune30,2005.However,theterminationwasextendedthroughJune30,2008toallowcollectionofthreeadditionalfullyearsofdata(2005‐2007)onthenew(April2004)lysimetersatLoganandSouthgate.Subsequently,anadditionalyear(2008)ofdatawascollectedatLogan,MurrayandSouthgateandisincludedherein.Gratitudeisexpressedtothefollowingindividualswhocollectedfielddatafrom2002–2008:DavidCarruth,MurrayParkwayGolfCoursesuperintendent;EarlHansen,BYUAgronomyDept;RickHeflebower,WashingtonCountyExtensionagent;JulieBreckenridge,WashingtonCountyWaterConservancyDistrict;SergioSolis,SunbrookGolfCoursesuperintendent;ConradBarrow,SunbrookGolfCourse;SherrieFox,SouthgateGolfCourseandUSUBIEstuentsBurdetteBarker,MusaDlamini,DarrenFillmore,WesleyHopwoodandRyanMcBride.Musa,Ryan,Darren,MichaelKohlerandOmarAlminagortaprovidedvaluableanalysisofseasonallysimeterandweatherdataforannualreports.Burdetteprovidedconsiderableassistancewiththefinalreport.TheassistanceofNancyHanks,AllisonBarnes,KellyMcKee,MeganPoulton,andShelleyComendant,USUBIEstaffassistantsisappreciatedfortheirhelpinpreparingthevariousannualreports.ParticulargratitudeisextendedtoRebecaOlsenforherwordprocessingandeditingskillsincompletingthefinalreport.

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TABLEOFCONTENTS

ExecutiveSummary........................................................................................................................ ii

ACKNOWLEDGEMENTS ................................................................................................................. iv

VERIFICATIONOFTURFGRASSEVAPOTRANSPIRATIONINUTAH...................................................1

INTRODUCTION.........................................................................................................................................................1EvapotranspirationEstimation .................................................................................................................................3

PROCEDURES..................................................................................................................................6

LysimeterTechniquesforMeasurementofTurfgrassWaterUse ............................................................................6FIELDPROCEDURES(DATACOLLECTION)..................................................................................................................9

WeatherDataCollection ......................................................................................................................................9SiteDescriptions.................................................................................................................................................11

DataAnalysis...........................................................................................................................................................14RESULTSANDDISCUSSION……………………………………………………………………………………………………..17

ObservationandCalculationPeriods .................................................................................................................17WeatherDataAdjustmentsandCalculatedReferenceEvapotranspiration ......................................................19LysimeterWaterBalanceandCalculatedKcrValues...........................................................................................23EstimatedMonthlyTurfgrassCropCoefficients.................................................................................................33

SUMMARYandCONCLUSIONS.....................................................................................................41

REFERENCES .................................................................................................................................43

APPENDICES .................................................................................................................................45

APPENDIXA:WorkTasksbyObjective ..................................................................................................................45APPENDIXB:TurfLysimeterDataCollectionProtocol...........................................................................................46APPENDIXC:Weatherstationsensorsandobservationparameters ....................................................................49APPENDIXD:SummaryofDataCollectedatLogan,1991‐2001............................................................................50APPENDIXE:CorrectionsMadetoWeatherData .................................................................................................52APPENDIXF:AdjustmentsMadetoIndividualLysimeterDrainageValuesDuetoOvertopping ..........................54

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ListofTablesTable1:INstallationdatesanddepthoflysimeters.....................................................................................................8

Table2:CoordinatesandElevationsofElectronicWeatherstationsatTurfLysimeterSitesinUtah .......................10

Table3:Availablewatercontentandinitialsoilwatercontentsusedinthesoilwaterbalancemodel ...................16

Table4:LoganGolfandCountryClubbeginningandendingdatesfordataCollectionandcalculationperiods......17

Table5:MurrayParkwayGolfCoursebeginningandendingdatesfordatacollectionandcalculationperiods ......18

Table6:SouthgateGolfCoursebeginningandendingdatesfordatacollectionandcalculationperiods ................18

Table7:SpanishForkbeginningandendingdatesfordatacollectionandcalculationperiods................................19

Table8:SunbrookGolfCoursebeginningandendingdatesfordatacollectionandcalculationperiods .................19

Table9:SolarRadiationCalibrationFactorandETrCalculationTimestepforEachSiteandYearatUtahTurfLysimeterSites,2002‐2008. ...............................................................................................................................20

Table10:ComparisonofDailyandHourlyCalculatedETrsValueswithandwithoutWindAdjustmentsforeachSiteandYearatUtahTurfLysimeterSites,2002‐2008.............................................................................................22

Table11:LoganGolfandCountryClubNew,EastandWestLysimeterFullSeasonWaterBalanceValueswithSeasonalCalculatedCropCoefficients ...............................................................................................................28

Table12:MurrayParkwayGolfCourseEastandWestLysimeterFullSeasonWaterBalanceValueswithSeasonalCalculatedCropCoefficients ..............................................................................................................................29

Table13:SouthgateGolfCourseEastandWestLysimeterFullSeasonWaterBalanceValueswithSeasonalCalculatedCropCoefficients ..............................................................................................................................30

Table14:SpanishForkTurfPlotNorthandSouthLysimeterFullSeasonWaterBalanceValueswithSeasonalCalculatedCropCoefficients ..............................................................................................................................31

Table15:SunbrookGolfCourseEastandWestLysimeterFullSeasonWaterBalanceValueswithSeasonalCalculatedCropCoefficients ..............................................................................................................................32

TableD1:SeasonalTotalIrrigation,DrainageandTurfWaterUse,1991‐95,2000‐01,fromtwoLysimetersattheLoganGolfandCountryClub,Logan,Utah.PartialSeasonDatafor1996‐99....................................................50

TableD2:TurfgrassWaterUse(ET)andCropCoefficients(Kcm),1991‐95,and2000‐01,fromLysimetersattheLoganGolfandCountryClub,Logan,Utah.PartialSeasonDatafor1996‐99....................................................51

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LISTOFFIGURESFigure1a.PlanViewofinstalledlysimeter(typical).AfterDlamini(2003).................................................................7

Figure2.Excavationoflysimeterplot(Sunbrook,Nov2001).......................................................................................7

Figure1b.Cross‐sectionviewofinstalledlysimeter(typical).AfterDlamini(2003) ..................................................7

Figure3.Plasticperforateddrainpipeinlysimeterbottomandcornerraingagewell(Southgate,Apr2004) ..........7

Figure4.Placementofsodinpartiallyinstalledlysimeter(Southgate,Apr2004) ......................................................8

Figure5.Finishedlysimeterinstallation(Southgate,Dec.2004).................................................................................8

Figure6.Typicalelectronicweatherstationinstallation(Southgatelookingnorthward,05103anemometer) .......10

Figure7a.CumulativelysimeterETandETrforLoganGolfandCountryClub,Logan,Utah,2007 ............................24

Figure7b.CumulativelysimetercropcoefficientforLoganGolfandCountryClub,Logan,Utah,2007....................24

Figure8a.CumulativelysimeterETandETrforMurrayGolfCourse,Murray,Utah,2007 ........................................25

Figure8b.CumulativelysimetercropcoefficientforMurrayGolfCourse,Murray,Utah,2007................................25

Figure9a.CumulativelysimeterETandETrforSouthgateGolfCourse,St.George,Utah,2007 ...............................26

Figure9b.CumulativelysimetercropcoefficientforSouthGateGolfCourse,St.George,Utah,2007.....................26

Figure10.MonthlyKcrvaluesfortheLoganNewLysimeter,2004‐2008 ..................................................................33

Figure11.MonthlyKcvaluesfortheSpanishForkNorthLysimeter,2002‐2006. .....................................................34

Figure12.MonthlyKcvaluesfortheSouthgateEastLysimeter,2004‐2008. ............................................................34

Figure13.MonthlyKcvaluesfortheSouthgateWestLysimeter,2004‐2008. ..........................................................35

Figure14.AverageKcvaluesforeachmonthfortheLoganNewLysimeter..Obviousoutlierswereexcluded.ThedashedlinerepresentsthesuggestedfullseasonKcr. ...........................................................................................35

Figure15.AverageKcvaluesforeachmonthfortheSpanishForkNorthLysimeter.Obviousoutlierswereexcluded.ThedashedlinerepresentsthesuggestedfullseasonKcr. ...................................................................36

Figure16.AverageKcvaluesforeachmonthfortheSouthgateEastLysimeter.Obviousoutlierswereexcluded.ThedashedlinerepresentsthesuggestedfullseasonKcr. ....................................................................................36

Figure17.AverageKcvaluesforeachmonthfortheSouthgateWestLysimeter.Obviousoutlierswereexcluded.ThedashedlinerepresentsthesuggestedfullseasonKcr. ....................................................................................37

Figure18.SuggestedKccurveforthehigherelevationareasofUtah.MonthlyKcvaluesaveragedbetweentheLoganNewandSpanishForkNorthLysimeters.Obviousoutlierswereexcluded. ..............................................37

Figure19.SuggestedKccurveforthelowelevationareasofSouthernUtah.MonthlyKcvaluesaveragedbetweenthetwoSouthgateLysimeters.Obviousoutlierswereexcluded..........................................................................38

Figure20.SuggestedKcocurveforthehigherelevationareasofUtahalongwithKcovaluesforeachmonthaveragedbetweentheLoganNewandSpanishForkNorthLysimeters.AdaptedfromFigure18. .....................39

Figure21.SuggestedKcocurveforthelowelevationareasofsouthernUtahalongwithKcovaluesforeachmonthaveragedbetweenthetwoSouthgateLysimeters.AdaptedfromFigure19. ......................................................40

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ClaytonLewischeckingwaterlevelsattheLoganGolfandCountryClub.

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VERIFICATIONOFTURFGRASSEVAPOTRANSPIRATIONINUTAH

INTRODUCTION

ThecontinuedcompetitionforwaterinUtahnecessitatesaccurateestimatesofwaterneedsandmanagementrequirementsforlegalwaterallocationaswellashydrologicconsiderations.Competitionforwaterisduetoincreasedurbanandruraldevelopmentaswellasdeclininggroundwaterlevelsandrecurringdroughtconditions.Thishighlightstheimportanceofcarefulwatermanagementincludingurbanwaterconservation,particularlyalongtheWasatchfrontandinhighgrowthareasofUtah.Themajorityofurbanwateruseinthesummerisfromirrigationoflandscapedareas,mostlyturf.Thus,itisimportanttoaccuratelyestimateturfgrasswaterusetosupportwaterconservationefforts.Previousstatewideestimatesofirrigatedcropwateruse(evapotranspiration,orET)inUtahreliedonacombinationofnearstate‐of‐the‐artmethodology(PenmantypeETequation,1982Kimberly,IDversion)atthetimecoupledwithacalibratedBlaney‐Criddleequation(Hill,1994).AcropcoefficientvalueforturfgrassETof0.56wasusedwiththe1982KimberlyModifiedPenmanCombinationalfalfareferenceETequation.Thiscoefficientvaluewasbasedontwoyearsofdata,asof1993,fromlysimetersinstalledintheLoganGolfandCountryClubgolfcourse.ErvinandKoski(1998),reportingaColoradostudy,suggestedthatwatercouldbeconservedbyirrigatingturfeverythreedayswithaKcof0.7(referencealfalfa,ETr,basis)forKentuckybluegrassand0.6forturftypetallfescue.Thesecoefficientvaluesforfescueandbluegrasswereabout7to25%higher,respectively,thantheReport#145value.This,plusotherconcerns,suggestedthatthecoefficientsderivedfromtheLoganGolfandCountryClubsiteinCacheValleymaynotbeapplicablethroughoutUtah.Thus,sitespecificverificationinarangeofconditionswasindicatedtoincreaseconfidenceinturfgrasswateruseestimates.Theoriginallyanticipatedproductofthisresearchwastodetermineverifiedcropcoefficients,Kc,(Wright,1982)forusewiththe1982KimberlyPenmanETrequation(Jensen,BurmanandAllen,1990)alongwithdailyweatherdatatoestimatenearrealtimeturfgrasswateruseinurbanareasofUtah.However,subsequenttotheinitiationofthiswork,theAmericanSocietyofCivilEngineers(ASCE)andtheIrrigationAssociationadopteda“standardized”formofthePenman‐MonteithETrequation(Allen,etal.,2005).ThedesireamongUtah’sstatewateragenciestousethe“standardized”methodprovidedanopportunitytocalibrateitforuseinestimatingturfgrassconsumptiveusethroughoutUtah.

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ObjectivesTheprimarypurposeofthisworkwastoverifyturfgrasscropwaterusecoefficientsforusewitheitheragrassreferenceET(ET0)oranalfalfareference(ETr)equationvalue.Specifically,thetwomainobjectiveswere:A.Studyturfgrasswaterusebymeasurementwithlysimetersincludingcollectionofsufficient

weatherdataateachsiteforusewithaPenmantypecombinationreferenceETequation.B.AnalysisofpreviouslycollectedturfgrassirrigationandsoilwatercontentdataattheBYU

AgronomyFarmnearSpanishFork,Utah.Neutronprobeandotherdatawerecollectedduring1990‐1992(or1993,approximately)fromtheBYUturfplots.However,usableconcurrentweatherdata,soilwatermeasurements,andirrigationdatawerenotobtainedforanytimeperiodforthesestudies.Thus,thisportionofthestudy,asincludedintheoriginalproposal,wasabandoned.

Worktasksbyobjective,ascontainedintheproposal,aregiveninAppendixA.

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EvapotranspirationEstimationEvapotranspirationisarelativelycomplexandnonlinearphenomenon,dependingontheinteractionofairtemperature,solarradiation,wind,vaporpressure(relativehumidity),aswellasonthecroptypeandgrowthstage(leafarea).Evapotranspiration(ET),consumptiveuse,orcropwaterusecanbeestimatedormeasuredbymanydifferenttechniquesdependingonstudyobjectivesandfinancialanddataresources.Thesetechniquesrangefromequationsthatuseonlymonthlyaveragetemperaturestothoroughlyinstrumentedfieldresearchsiteswithweighinglysimeters.Additionaldataoncropwateruseareavailablefromirrigationscheduling,experimentalplots,andfieldresearchstudies.ThegeneralformofthereferenceET‐cropcoefficientapproachtoconsumptiveuseequationsis: ET=KcETr+Ews (1)whereETistheestimatedcropevapotranspiration;KcisanempiricallydeterminedcropcoefficientrelatingcropETtoreferencecropETr;ETriscalculatedETforanalfalfareferencecrop;andEwsisestimatedwetsoilsurfaceevaporationadjustmenttoaccountforconditionsoccurringfollowinganirrigationorsignificantrain.ThisadjustmentismadewhentheKcvalueislessthan1.0,e.g.,intheearlygrowthstagesofarowcroporfollowingacuttingofalfalfa.EwsshouldbeignoredinsituationswheretheKcfactorincludestheeffectofawetsoilsurfaceonE.However,theirrigationscheduleshouldapproximatethatofthesitewheretheKcvaluesweredetermined.ImpliedinEq.1isaKcvaluerepresentingthe“basal”condition(Kcb)sinceEwsisexplicitlyshown.Analternateformofthecropwateruseequationis: ET=KcmETr (2)whereKcmisa"mean"cropcoefficient(Wright,1982)thatincludestheeffectofevaporationfromawetsoilsurfacefromatypicalirrigationscheduleforthegivencrop.Thevalueofacropcoefficient(KcorKcm)ataparticulargrowthstagedependsonplanttranspirationaswellasevaporationfromthesoilsurface.CaremustbeexercisedinapplyingKcmvaluesfromoneresearchsitetoothersiteswithdifferentirrigationpracticesandconditions.Areferencecropofalfalfaisatleast14inches(35cm)tallandadequatelyirrigatedsothattranspirationisnotlimitedbyavailablesoilmoisture.Anothercommonreferenceisthatofclippedgrass(ET0),waternotlimiting.TheavailabilityofreasonablypricedelectronicweatherstationshasallowedroutineuseofPenmantypeequationsforestimatingreferencecropET(ETr).

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ReferenceCropEvapotranspirationTheASCEStandardizedReferenceEvapotranspirationEquationwasusedinordertoobtainwellacceptedreferenceevapotranspiration(ETrs)values.DuetonighttimehighwindconditionsattheLoganGolfandCountryClub,itwasdecidedthatdailysumsofhourlycalculatedETrsshouldbeused.Thiswasbecausethehighwindatnightwhentemperaturesarecool,andturfgrassstomataareclosed,resultsinahighcalculationofETrifcalculationsaremadeusing24hourdataonly.AprogramwaswritteninVisualBasicforcalculatingdailyASCEstandardizedETrsbysumminghourlyETrvalues.Manyreferenceevapotranspirationequationshavebeenusedhistorically.Asmentionedpreviously,theAmericanSocietyofCivilEngineers(ASCE)andtheIrrigationAssociationadopteda“standardized”formofthePenman‐MonteithETrequationin2005(Allen,etal.,2005).ThisequationisnowagenerallyacceptedmethodofcalculatingETr.TheASCEstandardizedPenman‐MonteithequationoverestimatesETrinthespringandfallatKimberly,Idaho(Wrightetal.,2000),wherethe1982KimberlymodifiedPenmancombinationequationwascalibrated,thusnecessitatingtheuseof“corrected”cropcoefficients(AllenandWright,2002).TheASCEStandardizedPenman‐MonteithETrsequationcanbeusedforbotha“tall”(alfalfa)or“short”(grass)referencecropcalculationmode:

(3)

whereETrsisthestandardizedreferenceevapotranspiration(mm/dormm/hr)fora“tall”crop(denotedbythesubscript“rs”),Δistheslopeofthesaturationvaporpressure–temperaturecurve(kPa/°C),Rnisthecalculatednetradiationatthecropsurface(MJ/m2/dorMJ/m2/hr),G issoilheatflux(MJ/m2/dorMJ/m2/hr),γisthepsychrometricconstant(kPa/°C),Cnisthenumeratorconstant(changeswithtimestepandreferencecroptype)(Kmms3/Mg/dorKmms3/Mg/hr),Tismeantemperatureforthecalculationinterval(dailyorhourly)(°C),u2ismeanwindspeedforthecalculationintervalataheightof2mabovetheground(m/s),esisthesaturationvaporpressureat2mabovetheground(kPa),eaisthemeanactualvaporpressureat2mabovetheground(kPa),Cdisthedenominatorconstant(changeswithtimestepandreferencetype(s/m).Theunitsforthecoefficient0.408arem2mm/MJ.Forthisstudya“tall”crop(alfalfa)wasusedasthereferencetypeandthecalculationswereperformedonanhourlybasis.W

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WaterBalanceEstimatesofEvapotranspirationWhenappliedtoanirrigatedplot,themassbalanceequationcanberepresentedas: P+I+Ri+Up=ET+DP+Ro+ΔS (4)wherePisprecipitation,Iisirrigation,Riissurfaceflowontothefield,Upiscapillarityorupwardflow,DPisdeeppercolation,RoisrunoffandΔSischangeinsoilmoisture(SW1–SW2).TheuseoflysimeterseliminatestheturfgrassRi,Up,andRotermsinEq.4.Thus,sinceP,I,DPandΔScanbemeasured,theETtermcanbeestimatedastheresidual.

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PROCEDURES

LysimeterTechniquesforMeasuringTurfgrassWaterUseAlysimeterisatankfilledwithsoilthatcontainsthesamevegetationastheadjacentarea.Alysimeterisolatesthesoilmassandvegetationsowatercannotenterorleave,thusmakingitpossibletoaccuratelymonitorwaterrequiredtomaintainplantgrowthtodetermineevapotranspiration(ET)orconsumptiveuse.ETisoftendeterminedwithlysimetersthatweighchangesinthesoilmoisture.Thescopeofthisstudyandcostofweighinglysimetersmadenon‐weighing,drainagetypelysimetersareasonablealternative.Thistypeofnon‐weighinglysimeterwasusedinafieldestimationofwetmeadowETintheUpperBearRiverofIdaho,UtahandWyoming(Hill,etal.,1989);inastudyofhydrophyte(bulrushandcattail)wateruseinCacheValley,Utah(Allen,PruegerandHill,1992)andinastudyofETfromformerlyirrigatedlandsintheSouthParkareaofColorado(Quinlan,BurmanandSiemer,1982).Twolysimeterswerepreviously(fallof1991)installedintheLoganGolfandCountryClubandcontinuedinusethroughthisstudy.Lysimetersspecificallyforthisstudywerefabricatedinearlyfall2001andinstalled,twoateachsite,beginninginNovember2001atSt.George(SunbrookGolfCourse)andMurrayParkwayGolfCourseandinspring2002attheBYUSpanishForkFarm.Subsequently,twomorelysimeterswereinstalledatSouthgateGolfCourse(2004,St.George)andonemoreatLoganmakingthreeatLoganandeleventotalatthefivesites.

Construction

Thelysimeterswereconstructedfrom10gaugesteelplates,whichwerecutandbent.Thejointswerearc‐weldedandthelysimeterswerethenpowdercoated(white).Thelysimetersare11.1squarefeet(40inchesx40inches)and18,24,or30inchesdeep,dependingonsiteandfabricationdate,withadrainagepipeoutletinacorner.Aperforated3or4inchdiameterplasticdrainagepipewasplaceddiagonallyacrossthebottom.Typicalinstallationplanandcross‐sectionviewsofinstalledlysimetersareshowninFigure1.

InstallationMethods

Lysimeterswereinstalledinrepresentativeareasofirrigatedturf.Thesodmatwasremovedwithashovelandremainingmaterialwasremovedandplacedonsheetsofplywoodintheorderofremoval(Fig.2).Alysimeterwasplacedintheexcavatedholeandleveled.Alipofapproximately½to2inchesprotrudedabovethegroundtopreventsurfacewaterfromenteringthelysimeter.TheplasticdrainagepipewasplacedinthelysimeterasshowninFigure3.Thedrainagepipewascoveredbyabout2inchesofsandandthesoilremovedinexcavatingtheholewasreplacedin8to10inchliftsandcompacted.Intactsodpiecesremovedduringexcavationwerereplaced(Fig4)insimilarpatternasinajig‐sawpuzzle.Similarinstallationwas

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realizedateachlocationandthevegetationinthelysimeterswasrepresentativeofthatinthesurroundingarea(Fig5).

FIGURE1A.PLANVIEWOFINSTALLEDLYSIMETER

(TYPICAL).AFTERDLAMINI(2003)

FIGURE2.EXCAVATIONOFLYSIMETERPLOT

(SUNBROOK,NOV2001)

FIGURE1B.CROSS‐SECTIONVIEWOFINSTALLEDLYSIMETER(TYPICAL).AFTERDLAMINI(2003)

FIGURE3.PLASTICPERFORATEDDRAINPIPEINLYSIMETERBOTTOMANDCORNERRAINGAGEWELL

(SOUTHGATE,APR2004)

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FIGURE4.PLACEMENTOFSODINPARTIALLY

INSTALLEDLYSIMETER(SOUTHGATE,APR2004)

FIGURE5.FINISHEDLYSIMETERINSTALLATION

(SOUTHGATE,DEC.2004)A15‐inchdiameterPVCpipewasplacedverticallyinaholeadjacenttothedrainpipeoutlet.Thiswascoveredwithasteellid(Fig4)andservedasamanholeforthe5gallon(atLogan)or6gallondrainagebuckets.Four‐inchdiameterraingageswereplacedin6‐inchdiameterPVCpipessunkintothegroundoutsidetwooppositecornersofthelysimeters(Fig3).Thetopsoftheraingageswereapproximatelyflushwiththesurface.InstallationdatesandlysimeterdeptharegiveninTable1.Thevegetationinthelysimeterswasmanagedthesameastheadjacentturf.Wheninstallationwasinthespring,measurementsbeganimmediately,eventhoughtheturfmaynothavebeenfullyestablished.

TABLE1:INSTALLATIONDATESANDDEPTHOFLYSIMETERS Lysimeter

Location InstallationDate Depth(in)LoganGolfandCountryClubEast&West September17,1990 18

New April7,2004 24MurrayGolfCourse November16,2001 30SouthGateGolfCourse April8,2004 24SpanishFork April9,2002 30SunbrookGolfCourse November15,2001 30

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FIELDPROCEDURES(DATACOLLECTION)

Alllysimetersiteswerevisitedweeklyduringtheearlyandlategrowingseason,usuallymid‐AprilandthroughOctober.Whereastwiceweeklyvisitsweremadeinthemid‐growingseasonwheredrainageamountscouldhavecausedovertoppingofthebucketsatlongerobservationintervals.TwiceweeklyvisitsweregenerallymadeatLogan,SpanishForkandSouthgate.Ateachvisitmeasurementsweremadeofwaterinthetworaingagesandthevolumeordepthofwaterinthedrainagebucket.Ifnecessary,grasswasclippedfromaroundtheraingages.AprotocolforthelysimeterobservationsisinAppendixB.Thedrainage(ifany)wasmeasuredwitha1000mlgraduatedcylinder;largerdrainageamountsweremeasuredastwodepthreadingsinthedrainagebucket,takenatoppositesidesofthebucket.Aftereachreadingraingagesanddrainagebucketswereemptied.Occasionallyadditionalwaterwasaddedtosomeofthelysimetersinordertoinducedrainage.Thiswastypicallydoneonlysimeterswhichhadnotproduceddrainageforanextendedperiodoftime.Consumptiveuse,evapotranspiration,ofthelysimetervegetationwascalculatedusingasimplewaterbalanceequation: CU=ETlys=∆SW+(Irrigation+Rain)+Wadded–Drain (5)

whereCUisconsumptiveuse,equivalenttoevapotranspiration,ETlys;∆SWischangeinsoilwater;(Irrigation+Rain)isthecontentofaraingage(whichcouldbebothirrigationand/orrain);Waddedisextrawateraddedtothelysimeter(bydumpingbucketsofwaterasdescribedabove)andDrainisdrainagewaterinthebucket.Thechangeinsoilwater,∆SW,wasassumedtobenegligibleaslongasdrainageoccurredregularly.However,duringsomeseasonsandparticularlyatMurray,drainagedidnotoccurforseveralweeksatatime.WEATHERDATACOLLECTIONAutomatedelectronicweatherstations(EWS)wereequippedtomonitorairtemperature,soiltemperature,relativehumidity,solarradiation,windspeed,winddirection(exceptatLogan)andprecipitation.Thesensorsweresampledevery10secondsandhourlyanddailymaximums,minimums,averages,andtotalswerecalculatedandsavedinon‐boardmemory.EachstationwasoutfittedwithaCampbellScientific,Inc.(CSI)CR10Xmicrologger(CR10atSpanishFork).ThesensorsanddataloggerweremountedonCSItripodinstrumentplatforms(Figure6).SpecificinstrumentationcomponentpackagesforeachstationarelistedinAppendixC.

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FIGURE6.TYPICALELECTRONICWEATHERSTATIONINSTALLATION(SOUTHGATELOOKINGNORTHWARD,05103ANEMOMETER)Weatherstationlocations(coordinates)aregiveninTable2alongwithsiteelevationandeachstation’sanemometertypeandheightabovethegroundsurface.Elevationsvaryfrom2,572(Southgate)to4,790(Logan)ftabvmsl.The014A(MetOne)anemometerisacuptypedevicewhereasthe05103(R.MYoung)isapropellertype.SensorheightsaregreateratLoganandMurrayinanattempttoelevatethesensorsabovesprinklerstreamheights.Weatherdataforallthesites(exceptSunbrook)arepresentlyavailableonthewebatURL:http://extension.usu.edu/agweather.TABLE2:COORDINATESANDELEVATIONSOFELECTRONICWEATHERSTATIONSATTURFLYSIMETERSITESINUTAH

Site Latitude LongitudeElevation

(ft)Elevation(m)

AnemometerTypeHeight(m)

LoganGolfandCountryClub N41°44.682' W111°47.363' 4790 1460 014A 4N40°37.881' W111°55.190' 4294 1309 014A 4MurrayGolfCourse

SouthGateGolfCourse N37°04.434' W113°35.414' 2572 784 05103 3N40°04.031' W111°37.753' 4680 1427 014A 3SpanishFork

SunbrookGolfCourse N37°06.488' W113°38.044' 2678 816 05103 3

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SITEDESCRIPTIONSCacheValley–LoganGolfandCountryClubThegolfcourseissituatedinthemouthofLoganCanyon,ontheeastsideofCacheValleyinNorthernUtah,about2.5milesENEalongHighway89fromthe400NorthandMainStreetintersectioninLoganatanelevationofabout4790feet.Thecourseitselfisonanoldlaketerrace,depositedunderancientLakeBonneville.ThesoilisclassifiedasaRicksgravellyloamwithparentmaterialofalluviumanddeltaicsedimentsderivedfromlimestone,sandstoneandquartzite.Thelysimetersitehas6‐12inchesofloamtopsoilunderlaidbygravellyloam(includesriver‐rungraveluptocobblesize,Fig7).Wintertemperaturesdropaslowas20degreesbelowzeroFahrenheit,whereassummerhightemperaturesmayreach90degreesFahrenheitandabove.Thefrostfreeperiodis140to160days.Normal(1971‐2000)annualprecipitationis19.9inches.ThelysimetersaresituatedontheSEsideofthecourseclosetotheLoganCanyonmouth,westofthegreensnurseryandnorthofthefairwayforthe3rdhole.TheturfisaMerionbluegrass.Thecuttingheightissetat1½inchesintherough,wherethelysimetersarelocated,andat3/4ofaninchinthefairways.Theirrigationseasonisgenerallyfrommid‐MayintolateSeptemberorearlyOctober.Irrigationisin12‐minutecyclesupto2timesperday,ifneeded.Sprinklersareplacedina65ft.triangularspacingwithnozzledischargeof20.5gpm.Thefirstseasonoflysimeterdatacollectionbeganinthespringof1992(EastandWest)andMay2004(New)andhascontinuedtothepresent.Datacollectionwasinitiatedinthespringaftersnowmeltandcontinuedonintolatefallorearlywinter,untilsignificantsnowcover.Theperiodofmeasurementofturfgrasswaterusevariedfromyeartoyear,asaffectedbytheoccurrenceofsnowinthespringandthefall,butwasgenerallyfrommid‐ApriltolateOctober.Weatherdatafromtheweatherstationwasretrievedonceperweek,priortowhenthewebsitefiletransferprotocol(FTP)processwasestablished.SaltLakeCounty–MurrayParkwayGolfCourseThegolfcourseislocatedinmidSaltLakeValley,about0.5mileseastoftheJordanRiver,southofI‐215andnorthofWinchesterBlvd(66thSouth)inMurray.ThelocalareasoilisclassifiedasaKidmanveryfinesandyloamwithparentmaterialoflacustrinedeposits.Thelysimetersiteisonimported(hauledin)soilmaterial.Thereare6‐10inchesofloamtopsoilunderlainbyclayeygravel(uptocobblesize,Fig8).Itisnearthevalleybottomatanelevationofabout4285feet.Wintertemperaturesdropaslowas5degreesbelowzeroFahrenheit,whereassummerhightemperaturesmayreach95degreesFahrenheitandabove.Thefrostfreeperiodis160to180days.Normal(1971‐2000)annualprecipitationis16inches.Thelysimetersaresituatedonthesouthsideofthecourse,northofthefairwayforthe16thhole,about70feeteastofthe150yardmarker,390feetNWofthemaintenanceshedand200feetnorthoftheweatherstation.TheturfisaKentuckybluegrassandperennialryegrass

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mixture.Thecuttingheightissetat2inchesintherough,wherethelysimetersarelocated,andat3/4ofaninchinthefairways.TheirrigationseasonisgenerallyfromearlyMayintoearlyOctober.Irrigationisin9‐minutecyclesupto3timesperday,ifneeded.Sprinklersareplacedina70ft.triangularspacingwithnozzledischargeof22.5gpm.Thefirstseasonoflysimeterdatacollectionbeganinthespringof2002andhascontinuedtothepresent.Datacollectionwasinitiatedinthespringaftersnowmeltandcontinuedonintolatefallorearlywinter,untilsignificantsnowcover.Theperiodofmeasurementofturfgrasswaterusevariedfromyeartoyear,asaffectedbytheoccurrenceofsnowinthespringandthefall,butwasgenerallyfromearlyApriltolateOctober.DatafromtheweatherstationwasobtainedfromoccasionalsitevisitsaswellasfromthewebsiteFTPprocess.UtahCounty–BYUSpanishForkFarmTheBYUAgronomyturfplotsareabout3¼milesSSEofSpanishForkandabout¾mileSEoftheBYUDairy(nolongerinexistence).Theplotsareonanoldlaketerrace,depositedunderancientLakeBonneville.ThesoilisclassifiedasaTimpanogosloamwithparentmaterialoflacustrinedepositsderivedfromlimestone,quartziteandgranite.Thelysimetersitehasabout24inchesofloamtopsoilunderlainbysiltloam(Fig9).ItislocatednearthemouthofSpanishForkCanyonatanelevationofabout4700feet.Wintertemperaturesdropaslowas10degreesbelowzeroFahrenheit,whereassummerhightemperaturesmayreach95degreesFahrenheitandabove.Thefrostfreeperiodis150to170days.Normal(1971‐2000)annualprecipitationis21.6inches.Thelysimetersaresituatedabout240yardsSSWofthefieldshed,180yardsSWoftheweatherstationandabout15feeteastofaline‐sourcesprinklerusedtoapplyvaryingamountsofwatertotheturfplots.Theturfintheplotssurroundingthelysimetersisafescue.However,thelysimeterswerere‐soddedwithbluegrass.Cuttingheightwasabout2inchesandthelysimeterswerehandclippedtomatch.Theirrigationseasonwasgenerallyfrommid‐MayintoearlyOctober.Irrigationwasscheduledaboutonceperweekwiththedurationadjustedasneededtoprovidetheappropriatedepthofwateratthelysimeters.Sprinklerswereplacedabout20ft.apartalongthelinewithnozzledischargeof8‐9gpm.Thefirstseasonoflysimeterdatacollectionbeganinthespringof2002andcontinuedthrough2006whenfarmmanagementchanged.Datacollectionwasinitiatedinthespringaftersnowmeltandcontinuedonintolatefallorearlywinter,untilsignificantsnowcover.Theperiodofmeasuringturfgrasswaterusevariedfromyeartoyear,asaffectedbytheoccurrenceofsnowinthespringandthefallbutwasgenerallyfromearlyApriltolateOctober.Weatherdatafromtheweatherstationwasobtainedfromoccasionalsitevisitsaswellasfromthewebsite.WashingtonCounty–SouthgateGolfCourseThegolfcourseis2milesSSWofSt.Georgeabout0.3mileswestoftheI‐15crossingovertheSantaClaraRiver.ItislocatedalongtheSantaClaraRiveratanelevationofabout2550feet.

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ThesoilisclassifiedasaToblerfinesandyloamwithparentmaterialofalluviumderivedfromsandstoneandshale.Thereddishcoloredsandysoilismorethan3feetdeep(Figs3and4).Wintertimetemperaturesaremoderatealthoughminimumsdropbelowfreezing,whereassummertimehightemperaturesmayreach110degreesFahrenheitandabove.Thefrostfreeperiodis210to240days.Normal(1971‐2000)annualprecipitationis8.8inches.Thelysimetersaresituatedaboutinthemiddleofthecourse,about100yardseasterlyoftheclubhouse,about200ftfromthe1stteeandabout35to50feetsouthandeastoftheweatherstation(Fig10).TheBermudagrassturfisoverseededbyperennialryegrassintheearlyfall(September).Thecuttingheightissetat1½inchesintheroughnorthofthefairway,wherethelysimetersarelocated.Irrigationoccursallyearwiththefrequencyvaryingfromdailyinthesummertoonceeveryweekorlessfrequentinthewinter,dependingontheoccurrenceofwinterrains.TheirrigationdurationisadjustedtomatchETvaluesandspecificlocationsoilconditionsacrossthecourse.Sprinklersareplacedina70ft.triangularspacingwithnozzledischargeof32gpm.ThefirstseasonoflysimeterdatacollectionbeganinJuneof2004andcontinuedintomid‐December2008.Datacollectioncontinuedgenerallyyeararound.Theperiodofmeasurementofturf‐grasswaterusevariedsomewhatfromyeartoyear,asaffectedbypersonnelavailability.Theweatherdatafromtheweatherstationwasobtainedfromoccasionalsitevisitsaswellasfromthewebsite.WashingtonCounty–SunbrookGolfCourseThegolfcourseisabout3¼milesWNWofSt.Georgeandabout2milesSSWofSantaClara.ItislocatedalongtheSantaClaraRiveratanelevationofabout2670to2720feet.ThesoilisclassifiedasaToblerfinesandyloamwithparentmaterialofalluviumderivedfromsandstoneandshale.Thelysimetersitesandyloamsoilisuniformandmorethan3feetdeep(Fig2).Wintertemperaturesaremoderatealthoughminimumsdropbelowfreezing,whereassummerhightemperaturesmayreach110degreesFahrenheitandabove.Thefrostfreeperiodis210to240days.Normal(1971‐2000)annualprecipitationis8.8inches.Thelysimetersaresituatedinthenorthendofthedrivingrange,whichisaboutinthemiddleofthecourse,270yardsnorthoftheclubhouse,130feetsouthofthemaintenanceshedandaboutto230feetnortheastoftheweatherstation(Fig11).TheKentuckybluegrass/perennialryegrass/Bermudagrassturfisoverseededbyannualryegrassintheearlyfall(September).Duetoherbicideeffects,thelysimetersandadjacentareawerere‐soddedtoturftypefescuemid‐June2004.Thecuttingheightissetat1½incheswherethelysimetersarelocated.Irrigationoccursduringthenightandisyearround.Irrigationfrequencyvariesfromdailyinthesummertoonceeveryweekorlessfrequentlyinthewinter,dependingontheoccurrenceofwinterrains.TheirrigationdurationisadjustedtomatchETvaluesandspecificlocationsoilconditionsacrossthecourse.Sprinklersareplacedina65foottriangularspacingwithnozzledischargeof30to35gpm.

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Thefirstseasonoflysimeterdatacollectionbeganin2002andcontinuedthrough2006.Datacollectioncontinuedgenerallyyearround.Theperiodandconsistencyofmeasuringturfgrasswaterusevariedsomewhatfromyeartoyear,asaffectedbypersonnelavailability.Theweatherdatafromtheweatherstationwasobtainedfromoccasionalsitevisitsaswellasfromthewebsite.

DataAnalysis

WeatherData

Thecollectedweatherdatawasanalyzedandreviewedtoremoveerrorsandinaccurateormissingvalues.ThesolarradiationsensorcalibrationwascorrectedforeachseasonbycomparingobserveddailytotalsolarradiationwiththeoreticalcleardaysolarradiationusingtheproceduredescribedinHill(1994)andAllen,etal.(2005).Themostfrequentcorrectionsinvolvedmissinghourlydata.Onsuchoccasions,valuesforthemissinghourwereestimatedbyaveragingthevaluesfromthehoursbeforeandafterthemissingone.DetailsofthecorrectionsoradjustmentsmadetotheweatherdatabysiteandyeararegiveninAppendixE.

LysimeterData

Actualevapotranspiration(ETa)wascalculatedbyperformingasimplewaterbalanceforeachlysimeter.Asummationwasdonefortotalrainplusirrigationmeasuredinthetworaingagesneareachlysimeterandanaverageofthetwovalueswastakentorepresenttherainplusirrigationwhichwasappliedoverthelysimeterarea.Thisvaluewasaddedtothesumofadditionalwaterappliedtothelysimeter(whichwasconvertedintoanequivalentdepthoverthelysimeter).ThesumoftheequivalentdrainagewassubtractedfromthisvaluetoobtaintotalETforthecalculationperiod(seeEquation5).AnentirecalculationperiodETlyswasdeterminedby: ∑ETlys=∑(R+I)+∑Wadded‐∑D (6)where ETlysislysimeterestimatedevapotranspiration(in),Risrain(in),Iisirrigation(in),Waddediswateradded(in)andDisdrainage(in). Themeasuredbucketdrainagedepthwasconvertedintoanequivalentdepth,by:

(7)

whereDistheequivalentdepthofdrainageoverthelysimeter(in),havgistheaverageheightofwaterinthedrainagebucket(in),Alysistheareaofthelysimeter(1600sqin),Dtopisdiameter

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ofthetopofthebucket(in),Dbottomisdiameterofthebottomofthebucket(in)andhbucketisheightofthebucket(in).DailySoilWaterBalanceModel

Onanumberofoccasionsfornearlyallofthesitesthedrainagebucketswereobservedtohaveovertoppedbetweenvisits.Suchaneventcausesalossofdatabecausetheexactvolumeofdrainageisnotknown.InordertoobtainareasonableestimationoftheactualdrainageontheseoccasionsamodelwasdevelopedinVisualBasic.Themodelperformedrunningsoilwaterbalanceforeachdayduringthecalculationperiodfromwhichitcalculateddailydeeppercolation(DP)(seeEquation6).Thefirstreadingwasignoredbytheprogramsincethetotalprecipitationwhichresultedintheinitialdrainagereadingwasnotknown.Thedailysoilwaterbalancemodelisrepresentedby: DPi=(SW1)i‐(SW2)i+(R+I)i+(Wadded)i–Kc(ETrs)i (8)whereDPiisdeeppercolation(in),(SW1)Iistheinitialsoilwatercontentforthecurrentday(in),notethat(SW1)i=(SW2)i‐1(SW2)Iisthefinalsoilwatercontentforthecurrentday(in),(R+I)iistherainplusirrigationobservedforcurrenttheday(in),(Wadded)Iisthewateraddedtothelysimeteronthecurrentday(in),Kcisthecropcoefficientdeterminedbytheuser(decimal)and(ETrs)IistheASCEstandardizedreferenceevapotranspiration(in).InputforthemodelwasacommadelineatedfilecontainingthesumofthehourlycalculatedETrsforeachdayaswellasthelysimeterreadingsforeachobservation.Areasonablefullseasoncropcoefficientwasinputintothemodelaswellasanavailablewatercontentofthesoilinthelysimeter(AW)andtheinitialsoilwatercontentasestimatedforthecalculationperiod(SW0).TheSW0wasassumedtobeequaltotheAWfornearlyallofthelysimeterseachyear.Thisassumptionwasjustifiedbecausetypicallyacalculationperiodbeganearlyintheyearanddrainagewasoftenobservedonthefirstobservation,meaningthatthesoilwatercontentwasatfieldcapacityatthattime.Valuesofsoilparameters,AWandSW0usedforthecalculationsperformedbythesoilwaterbalancemodelaregiveninTable3.TheSW0valueatMurrayfor2003wasassumedtobehalfoftheAW,becausenoorlittledrainagewasobservedateitherlysimeterfortheentireseason(0inchesattheEastand0.03inchesattheWest).Thiswasneededinordertoobtainreasonableresultsfromthemodel.

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TABLE3:AVAILABLEWATERCONTENTANDINITIALSOILWATERCONTENTS

USEDINTHESOILWATERBALANCEMODEL AW SW0Location (in) (in)LoganGolfandCountryClubEast&West 2.6 2.6

New 3.2 3.2MurrayGolfCourse* 4.6 4.6SouthGateGolfCourse 2.4 2.4SpanishFork 4.6 4.6SunbrookGolfCourse 3.0 3.0

*TheSW0forbothlysimetersatMurrayGCin2003wassetto2.3in.Themodelcouldbeusedtocalculatethemeancropcoefficientfortheseasoniftherewerenoproblemswithovertoppeddrainagebuckets,oriftheseeventshadbeenadjustedfrompreviousrunsofthemodel.TheKcvaluecouldbedeterminediftheinputKcvaluewereadjusteduntilthecalculateddeeppercolationwasequaltothemeasured,oradjusted,drainage.ThisprovidedKcvalueswhichcouldbeusedtoverifythevaluesobtainedbythemethoddescribedinEquations5and6.Themodelestimatesdrainagebasedonasoilwaterbalance,forthosedayswhenadrainagebucketspilledovertop(andthuslostdata).Thisestimateddrainagevaluewastheninsertedintothedatafileandthemodelwasrunagain.TheKcvalueswereobtainedusingtheadjusteddrainagevalues.AdescriptionoftheadjustmentsisgiveninAppendixF.

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RESULTSANDDISCUSSIONOBSERVATIONANDCALCULATIONPERIODSTheperiodforwhichconsumptiveusecalculationswereperformedeachyearvariedfromlocationtolocationandwerenotalwayscontinuousthroughoutthegrowingseason.ThebeginningandendingdatesofweatherandlysimeterdatacollectionandthecalculationperiodsforLogan,Murray,SpanishFork,SouthgateandSunbrook,aregiveninTables4through8,respectively.Fullcalendaryearweatherdatawasavailablefornearlyeverylocationandyearofthestudywiththefollowingexceptions:January1throughMarch31,2006wasomittedatMurrayduetoerrorsinthedata,SouthgatedatabeganonJune23,2004andSunbrookdatabeganonFebruary22,2002(Tables5,6,and8).ThecalculationperiodandobservationperiodforlysimeterdataattheLogangolfcoursearethesameeveryyearexcept2004and2006(Table4).ThenewlysimeteratLoganwasinstalledonApril7,2004.ForthispurposethecalculationperiodforthatyearbeganonMay7.ThecalculationperiodbeganonApril26,2006duetosomeinconsistenciesinthedatacollectedonApril19fortheWestlysimeter;thereforethefirsttworeadingswereneglected.

TABLE4:LOGANGOLFANDCOUNTRYCLUBBEGINNINGANDENDINGDATESFORDATACOLLECTIONANDCALCULATIONPERIODS

Weather Lysimeter CalculationPeriodBeginDay EndDay BeginDay EndDay BeginDay EndDayYear

Date Day Date Day Date Day Date Day Date Day Date Day2002 1‐Jan 1 31‐Dec 365 25‐Mar 84 14‐Oct 287 25‐Mar 84 14‐Oct 2872003 1‐Jan 1 31‐Dec 365 17‐Mar 76 13‐Oct 286 17‐Mar 76 13‐Oct 2862004* 1‐Jan 1 31‐Dec 366 27‐Mar 87 18‐Oct 292 7‐May 127 18‐Oct 2922005 1‐Jan 1 31‐Dec 365 15‐Mar 74 24‐Nov 328 15‐Mar 74 24‐Nov 3282006 1‐Jan 1 31‐Dec 365 14‐Apr 104 8‐Nov 312 26‐Apr 116 8‐Nov 3122007 1‐Jan 1 31‐Dec 365 5‐Apr 95 17‐Nov 321 5‐Apr 95 17‐Nov 321*ThenewlysimeterwasinstalledonApril7,2004.ThisisthereasonthecalculationperiodbeganonMay7.

TheonlyyearatMurraywhichhadacalculationperioddifferingfromthelysimeterdataperiodofrecordwas2005(Table5).ThiswasbecauseofanabnormallylargeprecipitationeventonApril4.Thiseventcausedskewedresultsandthusthedatawasnotincludedforthepreviousweeksorthefollowingtwoweeksinordertoinsureamoretypicalsituation.

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TABLE5:MURRAYPARKWAYGOLFCOURSEBEGINNINGANDENDINGDATESFORDATACOLLECTIONANDCALCULATIONPERIODS

Weather Lysimeter CalculationPeriodBeginDay EndDay BeginDay EndDay BeginDay EndDayYearDate Day Date Day Date Day Date Day Date Day Date Day

2002 1‐Jan 1 31‐Dec 365 4‐May 124 14‐Oct 287 4‐May 124 14‐Oct 2872003 1‐Jan 1 31‐Dec 365 15‐Apr 105 13‐Oct 286 15‐Apr 105 13‐Oct 2862004 1‐Jan 1 31‐Dec 366 29‐Mar 89 15‐Nov 320 29‐May 89 15‐Nov 3202005 1‐Jan 1 31‐Dec 365 7‐Mar 66 26‐Sep 269 25‐Apr 115 19‐Sep 2622006 1‐Apr 91 31‐Dec 365 20‐Mar 79 25‐Sep 268 20‐Mar 79 25‐Sep 2682007 1‐Jan 1 31‐Dec 365 2‐Apr 92 19‐Nov 323 2‐Apr 92 19‐Nov 323

ThecalculationperiodforSouthgateGolfCoursebeganonJune11,2004(Table6),whichwasaboutaweekafterinstallation.However,theweatherstationwasnotinstalleduntilJune22.TheweatherdataforJune11throughJune22wasobtainedfromthestationatSunbrookGolfCourse.Thiswasjustifiedbecauseoftheproximityofthetwoweatherstations(approximately3.4milesapart)andtheobservationthatdatafromthetwolocationswasquitesimilar.In2006therewasabreakindatacollectionduetochangesinpersonnelatbothSouthgateandSunbrook;thisisthereasonforthelatebeginningdateforthecalculationperiod.

TABLE6:SOUTHGATEGOLFCOURSEBEGINNINGANDENDINGDATESFORDATACOLLECTIONANDCALCULATIONPERIODSWeather Lysimeter CalculationPeriod

BeginDay EndDay BeginDay EndDay BeginDay EndDayYear

Date Day Date Day Date Day Date Day Date Day Date Day2004 23‐Jun 174 31‐Dec 366 9‐Apr 100 4‐Dec 339 11‐Jun 162 4‐Dec 3392005 1‐Jan 1 31‐Dec 365 10‐Mar 69 2‐Dec 336 10‐Mar 69 2‐Dec 3362006 1‐Jan 1 31‐Dec 365 23‐Jan 23 1‐Dec 335 23‐Jun 23 1‐Dec 3352007 1‐Jan 1 31‐Dec 365 24‐Jan 24 29‐Dec 363 24‐Jan 24 29‐Dec 363

TheonlyyearsatSpanishForkwithcalculationperiodsshorterthantheperiodofrecordforthelysimeters,were2002and2003(Table7).In2002waterwasaddedtobothlysimetersonMay20.Thelysimetershadbeeninstalledthepreviousmonthandhadmostlikelynotcompletelysettled.TheresultsseemedmuchmoreappropriatewhentheweekseffectedbythewateradditiononMay20wereeliminated.In2003therewasalatespringsnowfalleventonApril8,whichcausesinaccurateprecipitationreadings.Thus,thebeginningdateforthecalculationswaschangedtoApril30.

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TABLE7:SPANISHFORKBEGINNINGANDENDINGDATESFORDATACOLLECTIONANDCALCULATIONPERIODSWeather Lysimeter CalculationPeriod

BeginDay EndDay BeginDay EndDay BeginDay EndDayYearDate Day Date Day Date Day Date Day Date Day Date Day

2002 1‐Jan 1 31‐Dec 365 10‐May 130 3‐Oct 276 5‐Jun 156 3‐Oct 2762003 1‐Jan 1 31‐Dec 365 17‐Mar 76 10‐Nov 314 30‐Apr 120 10‐Nov 3142004 1‐Jan 1 31‐Dec 366 1‐Apr 92 10‐Nov 315 1‐Apr 92 10‐Nov 3152005 1‐Jan 1 31‐Dec 365 22‐Mar 81 2‐Nov 306 22‐Mar 81 2‐Nov 3062006 1‐Jan 1 31‐Dec 365 24‐Apr 114 11‐Oct 284 24‐Apr 114 11‐Oct 284

AnumberofdatacollectionproblemsoccurredatSunbrookGolfCourse.Theonlyyearsforwhichthecalculationperiodmatchedthelysimeterperiodofrecordwere2004and2005(Table8).In2002theweatherstationwasnotinstalleduntilFebruary22,sothecalculationperiodbeganatthenextlysimeterobservation(February25).DatacollectionwassporadicduringJanuary2003,thereforethecalculationperiodbeginsonFebruary3.In2006therewasalargegapinthelysimeterdatabetweenMarch29andJune26,sodataprevioustothisgapwasexcludedfromthestudy.

WEATHERDATAADJUSTMENTSANDCALCULATEDREFERENCEEVAPOTRANSPIRATIONSolarradiationsensorcalibrationcorrectionfactorsforeachsiteandyeararegiveninTable9.Acorrectionfactorlessthanoneindicatesthatrecordedsolarradiationsensorvaluesarehigherthanwhatwouldhavebeenobtainedfromafieldsensorwiththecorrectcalibrationprogrammedintothedatalogger.Correctionfactorsvariedfrom0.969(Murray,2007)to1.087(SpanishFork,2004).Thisindicatesthatfieldsensorvaluesvariedfromabout3%highto9%low.ThesensorsatLoganandMurraygenerallyrequiredlesseradjustmentsafterthefactthansensorsatothersites.Thecalculationtimesteps,hourlyordaily,thatwerepossibleateachsitearealsogiveninTable9.Generally,datafromtheyear2002werestoredonlyat2hourintervals,thushourlycalculationswerenotfeasible.Beginningwith2003,alldataloggers,exceptatSpanishFork,wereprogrammedforhourlydatastorage,whichfacilitatedhourlyaswellasdailytimestepcalculations.

TABLE8:SUNBROOKGOLFCOURSEBEGINNINGANDENDINGDATESFORDATACOLLECTIONANDCALCULATIONPERIODS

Weather Lysimeter CalculationPeriodBeginDay EndDay BeginDay EndDay BeginDay EndDayYearDate Day Date Day Date Day Date Day Date Day Date Day

2002 22‐Feb 53 31‐Dec 365 7‐Jan 7 5‐Nov 309 25‐Feb 56 5‐Nov 3092003 1‐Jan 1 31‐Dec 365 2‐Jan 2 10‐Nov 314 3‐Feb 34 10‐Nov 3142004 1‐Jan 1 31‐Dec 366 1‐Mar 61 21‐Sep 265 1‐Mar 61 21‐Sep 2652005 1‐Jan 1 31‐Dec 365 18‐Jan 18 28‐Dec 362 18‐Jan 18 28‐Dec 3622006 1‐Jan 1 31‐Dec 365 5‐Jan 5 16‐Oct 289 26‐Jun 177 16‐Oct 289

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TABLE9:SOLARRADIATIONCALIBRATIONFACTORANDETRCALCULATIONTIMESTEPFOREACHSITEANDYEARATUTAHTURFLYSIMETERSITES,2002‐2008.

Site YearRs

CalibrationFactor

CalculationTimeStep

Comments

Logan 2002 1.025 Dailya Hourlyparametersnotsaved

2003b 1.012 Hourly

2004 1.010 Hourly

2005 1.006 Hourly

2006 1.002 Hourly

2007 1.004 Hourly

2008 0.997 Hourly

Murray 2002 0.994 Daily Hourlyparametersnotsaved

2003b 0.978 Hourly

2004 0.986 Hourly

2005 0.987 Hourly

2006b 0.971 Hourly

2007b 0.969 Hourly

2008b 0.979 Hourly

Southgate 2004b 1.048 Hourly

2005 1.032 Hourly 2006 1.049 Hourly 2007 1.017 Hourly 2008 1.048 Hourly

SpanishFork 2002c 0.980/1.086 DailyClimateCenterstationhadbadRH,dailydewpointlimitwasused

2003 1.086 Daily Hourlyparametersnotsaved 2004 1.087 Daily Hourlyparametersnotsaved 2005 1.081 Daily Hourlyparametersnotsaved

2006 1.070 Hourly

Sunbrook 2002b 1.045 Daily Hourlyparametersnotsaved

2003b 1.078 Hourly

2004 1.084 Hourly 2005 1.068 Hourly 2006 1.082 Hourly 2007 1.070 Hourly aAwindlimitof110miles/daywasusedforthedailycalculationsforLoganin2002.Thiswindlimitwasbasedoncalculationsfor2003to2008hourlyanddailyETrcalculationsusingdifferentdailywindlimits.bPartialyearofdataasfollows:Logan2003=1Febto31Dec,Murray2003=1Febto21Dec,Murray2006=1Aprto31Dec,

Murray2007=1Janto28Nov,Murray2008=26Janto31Dec,Southgate2004=23Junto31Dec,Sunbrook2002=22Febto31Dec,Sunbrook2003=29Janto31Dec.cSpanishFork2002includesdatafromaUtahClimateCenterweatherstationthroughday234,datafortheremainderoftheyearwasmeasuredbythecurrentweatherstation.Onlydailycalculationswereperformed,dewpointwassettobenomorethan4°FbelowTminintheClimateCenterstationdailycalculations.SpanishFork2002hastwoRscalibrations,onefortheClimateCenterstationandoneforthecurrentstation.Calculationsfor2002weredoneusingtheCRPSMWmodel.

21

AcomparisonofASCEStandardizedPenman‐Monteithtallcrop(alfalfa)referenceET(ETrs)valuescalculatedusingbothdailyandhourlytimestepsisgiveninTable10forthefiveturflysimetersitesinUtah.Asnotedabove,onlydailycalculationtimestepswerepossiblein2002andatSpanishFork(exceptfor2006).TwosetsofwindandETrsvaluesareshowninTable10.Thefirst,denoted“Original”windrunorspeed,wasmadefromtheoriginalrecordedwindtravelandspeed,whereastheothercalculationofETrswasmadewith“Adjusted”winddata.Atemporaryco‐locationofelectronicweatherstationswithbothcuptype(MetOne014A)andpropellertype(R.M.Young05103)anemometerswasmadeintheSnowvilleareaaspartofanotherresearchstudy.Asaresult,wediscoveredthatthecuptypeanemometers(014A)givehigherwindvelocitiesthanthepropellertype(05103).FurthercalibrationchecksagainstaCSAT3sonicanemometerconfirmedthatthe014Areadhighandthe05103low.OnlySouthgateandSunbrook(Table2)havethepropellertype.ThisinfersthatETrsforSouthgateandSunbrookwouldberelativelylowerduetotheunderestimatedwindspeeds.Thus,thecalculatedcropcoefficient,withunadjustedwindspeed,wouldbehigherthanitshouldbe.Theconverseisthecasefortheothersites(Logan,MurrayandSpanishFork).InspectionofTable10indicatesthatthe“Original”averagewindtravelatLoganandMurrayisabout170andover125milesperday(mpd),respectively,andisabout100mpdatSpanishFork.WindtravelatSouthgateandSunbrookaveragesconsiderablylessatabout50and60mpd,respectively.ThecorrespondingdailytimestepcalculatedaverageannualETrsisabout79inchesatLogan,and64,58,64and70inches,respectively,atMurray,Southgate,SpanishForkandSunbrook.ThisillustratesthesensitivityoftheASCEStandardizedpenman‐Monteith,indeedanyPenmancombinationtypeETequation,towindspeed(orwindtravel).ThehighETrsatLogan,comparedwiththeconsiderablywarmersouthernUtahsitesissomewhatcounterintuitive.However,hourlytimestepcalculatedaverageannualETrsislowerthanthedailytimestepETrsvalueatsiteswiththehigherwindtravel,i.e.Logan(61in.vs.79),Murray(63in.vs.64)andSpanishFork(62in.vs.64).HourlycalculatedETrsishigherthandailyETrsatthelowerwindsitesofSouthgate(62in.vs.58)andSunbrook(71in.vs.70).Imposingthe“Adjusted”windreducestheETrsvaluesforthesiteswithcuptypeanemometers(Logan,MurrayandSpanishFork)whileincreasingcalculatedETrsatSouthgateandSunbrook,bothsiteswithloweraveragewind(Table10)andpropelleranemometers.Theneteffectofwindadjustmentforthehighwindsites(cupanemometers)wasabouta12%dropinwindtravel(Table10).Windtravelincreasedabout23%attherelativelylowwindsites(SouthgateandSunbrook)withtheadjustment.TheeffectofthewindadjustmentonETrswaslesspronounced.AnnualETrs,dailytimestepcalculation,averaged5%lessatthethreecupanemometer(014A)highwindsitesand10%moreatthetwopropelleranemometer(05103)lowwindsitesasaresultofthewindadjustmentcomparedtousingtheoriginalreportedwind.Similarly,hourlycalculatedETrsaveraged4%lessatthecupanemometer(014A)sitesand6%moreatthepropelleranemometer(05103)sites.

22

TABLE10:COMPARISONOFDAILYANDHOURLYCALCULATEDETRSVALUESWITHANDWITHOUTWIND

ADJUSTMENTSFOREACHSITEANDYEARATUTAHTURFLYSIMETERSITES,2002‐2008.CalculationsUsingDailyTimeStep CalculationsUsingHourlyTimeStep

AverageDailyWindRun(mpd)

AnnualETrsWith

OriginalWind

(inches)

AnnualETrsWithAdjustedWind

(inches)

AverageWindSpeed

(mph)

AnnualETrsWith

OriginalWind

(inches)

AnnualETrsWithAdjustedWind

(inches)

Site Year

Orig AdjASCEStd.

PMASCEStd.

PMOrig Adj

ASCEStd.PM

ASCEStd.PM

Logan 2002† 173 156 77.02 74.04 ‐‐‐‐‐ ‐‐‐‐‐ ‐‐‐‐‐ ‐‐‐‐‐ 2003* 185 168 81.80 78.63 7.69 6.99 62.08 60.07 2004 166 150 74.14 71.31 6.93 6.26 57.97 56.22 2005 162 146 74.55 71.67 6.76 6.09 58.07 56.29 2006 178 162 79.78 76.64 7.43 6.74 61.03 59.03 2007 171 154 84.01 80.61 7.11 6.43 65.30 63.09 2008 170 154 78.85 75.68 7.09 6.41 60.10 58.08 Average 172 156 78.59 75.51 7.17 6.49 60.76 58.80Murray 2002† 125 110 67.82 64.30 ‐‐‐‐‐ ‐‐‐‐‐ ‐‐‐‐‐ ‐‐‐‐‐ 2003* 128 113 66.59 63.08 5.34 4.70 65.70 63.12 2004 122 107 64.11 60.94 5.10 4.47 63.53 61.24 2005 128 113 64.24 61.09 5.33 4.70 62.57 60.35 2006* 124 109 57.78 54.81 5.15 4.52 56.29 54.12 2007* 125 110 68.81 65.21 5.22 4.60 67.81 65.17 2008* 121 106 61.01 57.68 5.01 4.38 59.68 57.23 Average 125 110 64.34 61.02 5.19 4.56 62.60 60.21Southgate 2004* 45 58 33.47 37.20 1.89 2.43 36.31 38.97 2005 44 57 60.47 67.06 1.84 2.38 65.84 70.47 2006 51 64 64.38 70.94 2.14 2.67 68.49 73.08 2007 54 67 67.13 73.89 2.24 2.77 71.67 76.48 2008 52 65 65.16 71.68 2.18 2.71 69.50 74.04 Average 49 62 58.12 64.15 2.06 2.59 62.36 66.61SpanishFork 2002** 107 93 64.34 59.84 ‐‐‐‐‐ ‐‐‐‐‐ ‐‐‐‐‐ ‐‐‐‐‐ 2003‡ 79 65 63.99 58.86 ‐‐‐‐‐ ‐‐‐‐‐ ‐‐‐‐‐ ‐‐‐‐‐ 2004‡ 94 80 61.91 57.87 ‐‐‐‐‐ ‐‐‐‐‐ ‐‐‐‐‐ ‐‐‐‐‐ 2005‡ 97 83 62.59 58.66 ‐‐‐‐‐ ‐‐‐‐‐ ‐‐‐‐‐ ‐‐‐‐‐ 2006 102 88 66.11 61.94 4.27 3.67 61.76 59.06 Average 96 82 63.79 59.43 4.27 3.67 61.76 59.06Sunbrook 2002*† 71 83 70.31 76.25 ‐‐‐‐‐ ‐‐‐‐‐ ‐‐‐‐‐ ‐‐‐‐‐ 2003* 65 78 70.71 76.88 2.80 3.33 71.05 74.94 2004 65 78 71.19 77.25 2.72 3.24 72.29 76.16 2005 60 73 66.53 72.53 2.51 3.03 67.86 71.66 2006 62 75 68.45 74.89 2.60 3.12 69.05 73.29 2007 62 75 70.00 76.59 2.60 3.13 72.84 77.38 Average 64 77 69.53 75.73 2.65 3.17 70.62 74.69†In2002Logan,Murray,andSunbrookdidnotrecordnecessaryparametersforETrcalculationsonanhourlytimestep*Partialyearofdata,seeTable9footnoteb.**SeeTable9footnotec.‡SpanishFork2002hadoutputeveryhour,howeverdailycalculationsweredonefortheUtahClimateCenterstationdata,2003through2005hadoutputevery2hours.

23

LYSIMETERWATERBALANCEANDCALCULATEDKCRVALUES

LysimeterwaterbalanceandcalculatedcropcoefficientsweredeterminedforeachyearateachsitefortheperiodofcalculationaslistedinTables4through8.Anestimateofactual(measured)ETawasmadefromthelysimeterwaterbalance.Forthe2007annualreportseasonalturfgrassETcropcoefficients(alfalfareference,ETr)wereestimatedusingdailyandhourlycalculationtimestepsforETrfromtheASCEstandardizedPenmanMonteith(ASCEstPM)andthe1982KimberlyPenmanCombination(1982KimPen)Equations.Thefollowingdiscussionandfigureswereadaptedfromthatannualreport.ComparisonsofcumulativecalculatedETrandtheseasonprogressionofaccumulatedlysimeterwateruseandcorrespondingKcvaluesthroughouttheseasonsareillustratedinFigures7,8,and9,respectively,forLogan,Murray,andSouthgate.ThedifferenceinETbetweenthetwooldlysimeters(EastandWest)andthenewlysimeteratLoganisparticularlyevidentinFigure7a.TherewasmoredifferencebetweentheestimatedETforthetwolysimetersatSouthgate(Figure9)thanatMurray(Figure8).ThesumofcalculatedhourlyETrwaslowerthanthedailytimestepETrsum,exceptatSouthgate(Figure9a).ThemostdramaticdifferenceisatLogan(Figure7a)wherethehourlyASCEstPMETrwas24%lessthanthedailycalculatedvalue.ThisisattributedtothehighnighttimecanyonwindsatLogan.Generally,theASCEstPMETrvalueswerehigherthantheETrofthe1982KimPen.Earlyinthestudy,attemptsweremadetocalculateweeklycropcoefficientvalueswiththeassumptionthattheKcvaluemaybeabitlowerintheearlyspringthanduringthesummer.TheresultswereextremelyerraticwithcalculatedKcvaryingfromover2tonegativevaluesinsuccessiveweeks.ThiseffectissomewhatillustratedinFigure9bwherethecumulativelysimetercropcoefficientfluctuatesfrom0.85downtoabout0.6andthenincreasesagaininsuccessivecalculationperiodsintheearlyseason.Thismaybetheresultofatimingmismatchbetweenweeklymeasurementsandtheoccurrenceofrain,irrigationandsubsequentdrainage.Itisalsoanartifactofthecalculationprocedurewhichdoesnotaccountforsoilwaterdepletionandsubsequentrefill,becausesoilwatercontentwasnotmeasured.Similarly,theadditionofextrawatertotheMurraylysimetercauseda“jump”inthecalculatedETandinthecropcoefficient(Figure8).

24

FIGURE7A.CUMULATIVELYSIMETERETANDETRFORLOGANGOLFANDCOUNTRYCLUB,LOGAN,UTAH,2007

FIGURE7B.CUMULATIVELYSIMETERCROPCOEFFICIENTFORLOGANGOLFANDCOUNTRYCLUB,LOGAN,UTAH,2007

25

FIGURE8A.CUMULATIVELYSIMETERETANDETRFORMURRAYPARKWAYGOLFCOURSE,MURRAY,UTAH,2007

FIGURE8B.CUMULATIVELYSIMETERCROPCOEFFICIENTFORMURRAYPARKWAYGOLFCOURSE,MURRAY,UTAH,2007

26

FIGURE9A.CUMULATIVELYSIMETERETANDETRFORSOUTHGATEGOLFCOURSE,ST.GEORGE,UTAH,2007

FIGURE9B.CUMULATIVELYSIMETERCROPCOEFFICIENTFORSOUTHGATEGOLFCOURSE,ST.GEORGE,UTAH,2007

27

Asaresultofconsiderationsmentionedabove,theASCEStandardizedPenman‐MonteithEquationwasusedwithanhourlycalculationtimestephereintoestimateETr(denotedETrs).Cropcoefficient(Kc)valueswereobtainedbydividingthemeasuredseasontotalETabythecorrespondingETrs.Boththeactualmeasureddrainage,intherecords,andanadjusteddrainagevaluearereportedinthefollowingtables.Theadjusteddrainage(seeAppendixF)wasobtainedfromusingareasonableprovisionalcropcoefficientinthesoilwaterbalance(drainage)model.Logan

WaterbalancevaluesforthethreelysimetersatLoganaregiveninTable11.ThenewlysimeterETvariedfrom21.6(2004)to35.2inches(2007)andthecalculatedKcvariedfrom0.51to0.66,witha5‐yearaverageof0.59.TheEastlysimeterETvariedfrom14.5(2004)to30.3inches(2002)andKcvariedfrom0.33to0.61,witha7‐yearaverageof0.42.TheWestLysimeterETwassomewhatlower,varyingfrom11.2(2004)to21.2inches(2007)andKcvariedfrom0.27to0.44,witha7‐yearaverageof0.34.CalculatedhourlytimestepwithadjustedwindETrsvariedfrom41.3to54.8inches.Drainageadjustmentsweremadetothe2004and2005dataonnewlysimeterandeveryyearontheolderlysimeters,exceptfor2004ontheEastlysimeter.Thenew(East)lysimeterwasinstalledin2004becauseoftheseeminglylowKcvaluesobtainedfromthetwoolderlysimeters(particularlytheWestlysimeter),whichwereinstalledin1991,incomparisonwith2002and2003datafromothersites.Datacollectiononthenew(whichiseastoftheoldEast)lysimeterbeganinearlyMay2004(Tables4and11).ThedifferenceinestimatedETamongtheLoganlysimetersisclearlyevidentincomparingETaandKcvaluesfromthenewlysimeterwiththeWestlysimeter(Table11)andsomewhatwiththeEastlysimeter(after2003).ConsideringonlythenewlysimeterdatawouldsuggestusinganaverageKcvalueofabout0.6forturfgrass,whichisabout7%higherthanthepreviouslyusedvalueof0.56(Hill,1994).

Murray

TurfgrasswateruseontheMurrayEastlysimeter(Table12)variedfrom22.2(2008)to30.5inches(2005).CalculatedETrsvariedfrom41.5to56.8inches.EstimatedKcfortheEastlysimetervariedfrom0.46to0.74,witha7‐yearaverageof0.57.TheWestlysimeterETwassimilar,varyingfrom23.2(2007)to30.2inches(2007).TheobservedKcvariedfrom0.43to0.70,witha7‐yearaverageof0.57.TheaverageKcforallyearsoverbothlysimeterswas0.57.Thevalueof0.57fortheaverageKcisalmostidenticaltothecropcoefficientvalue(0.56)usedinpreviousestimatesofturfET.

28

TABLE11:LOGANGOLFANDCOUNTRYCLUBNEW,EASTANDWESTLYSIMETERFULLSEASONWATERBALANCEVALUESWITHSEASONALCALCULATEDCROPCOEFFICIENTSNewLysimeter

Calc.PeriodYear

Begin End

Irrig.+Rain(in)

WaterAdded(in)

MeasuredDrain.(in)

AdjustedDrain.(in)

ET(in)

ETrs(in)

Kc

2004 7‐May 18‐Oct 26.07 0 4.19 4.45 21.62 40.06 0.542005 15‐Mar 24‐Nov 36.13 0 8.00 9.71 26.42 52.23 0.512006 26‐Apr 8‐Nov 33.51 2.87 5.14 5.14 31.24 47.43 0.662007 5‐Apr 17‐Nov 36.67 1.73 3.12 3.19 35.21 54.80 0.642008 30‐Apr 21‐Nov 29.89 1.73 4.17 4.20 27.42 47.31 0.58

AverageKc= 0.59

EastLysimeter KcSt.Dev.= 0.07

Calc.PeriodYear

Begin End

Irrig.+Rain(in)

WaterAdded(in)

MeasuredDrain.(in)

AdjustedDrain.(in)

ET(in)

ETrs(in)

Kc

2002 25‐Mar 14‐Oct 45.03 0 13.91 14.69 30.34 50.01 0.612003 17‐Mar 13‐Oct 38.05 0 9.80 9.80 28.25 52.82 0.532004 7‐May 18‐Oct 23.14 0 8.65 8.65 14.49 40.06 0.362005 15‐Mar 24‐Nov 34.11 0 12.88 13.75 20.36 52.23 0.392006 26‐Apr 8‐Nov 29.49 0 11.86 13.03 16.46 47.43 0.352007 5‐Apr 17‐Nov 31.55 0.87 9.80 10.89 21.53 54.80 0.392008 30‐Apr 21‐Nov 24.37 0 7.76 8.63 15.74 47.39 0.33

AverageKc= 0.42

WestLysimeter KcSt.Dev.= 0.10

Calc.PeriodYear

Begin End

Irrig.+Rain(in)

WaterAdded(in)

MeasuredDrain.(in)

AdjustedDrain.(in)

ET(in)

ETrs(in)

Kc

2002 25‐Mar 14‐Oct 39.30 0 13.86 20.33 18.97 50.01 0.382003 17‐Mar 13‐Oct 34.13 0 13.29 13.53 20.60 52.82 0.392004 7‐May 18‐Oct 25.21 0 13.04 14.06 11.15 40.06 0.282005 15‐Mar 24‐Nov 36.13 0 19.99 22.22 13.91 52.23 0.272006 26‐Apr 8‐Nov 32.80 0 14.83 16.51 16.29 47.43 0.342007 5‐Apr 17‐Nov 33.69 0.58 12.93 13.03 21.24 54.80 0.392008 30‐Apr 21‐Nov 31.91 0 9.64 11.08 20.83 47.39 0.44

AverageKc= 0.35

KcSt.Dev.= 0.06

SiteAverage AverageKcforalllysimeters= 0.44

KcSt.Dev.foralllysimeters= 0.12

29

TABLE12:MURRAYPARKWAYGOLFCOURSEEASTANDWESTLYSIMETERFULLSEASONWATERBALANCEVALUESWITHSEASONALCALCULATEDCROPCOEFFICIENTSEastLysimeter

Calc.PeriodYear

Begin End

Irrig.+Rain(in)

WaterAdded(in)

MeasuredDrain.(in)

AdjustedDrain.(in)

ET(in)

ETrs(in)

Kc

2002 4‐May 14‐Oct 28.6 0 0 0 28.60 44.65 0.642003 15‐Apr 13‐Oct 26.15 2.17 0 0 28.32 48.75 0.582004 29‐May 15‐Nov 30.11 1.73 3.58 3.58 28.26 53.08 0.532005 25‐Apr 26‐Sep 24.31 9.09 2.89 2.89 30.51 41.46 0.742006 20‐Mar 25‐Sep 23.96 6.79 2.58 6.34 24.41 46.14 0.532007 2‐Apr 19‐Nov 26.65 4.33 0.64 3.15 27.83 56.75 0.492008 2‐Apr 19‐Nov 22.57 0 0.35 0.35 22.22 48.03 0.46

AverageKc= 0.57


Calc.PeriodYear

Begin End

Irrig.+Rain(in)

WaterAdded(in)

MeasuredDrain.(in)

AdjustedDrain.(in)

ET(in)

ETrs(in)

Kc

2002 4‐May 14‐Oct 28.80 0 0 0 28.80 44.65 0.652003 15‐Apr 13‐Oct 27.59 2.17 0.03 0.03 29.73 48.75 0.612004 29‐May 15‐Nov 30.98 0 3.02 3.02 27.96 53.08 0.532005 25‐Apr 26‐Sep 24.80 6.06 1.78 1.78 29.08 41.46 0.702006 20‐Mar 25‐Sep 26.73 3.47 2.75 3.89 26.31 46.14 0.572007 2‐Apr 19‐Nov 29.32 2.60 0.14 1.73 30.19 56.75 0.532008 2‐Apr 19‐Nov 23.59 0 0.36 0.36 23.23 54.03 0.43

AverageKc= 0.57

KcSt.Dev.= 0.09



TheMurraysuperintendentusedaKcof0.56asaguideinirrigationscheduling.Asnotedearlier,theirrigationamountatMurrayismoderatedtoavoidcreatingorworseningatroublesomewetspotinaheavytrafficareatowardtheendofthe16thfairway.AsaresulttheestimatedturfETwasessentiallythesameasirrigationplusrainfall.Thus,thesimilaritybetweenKcvaluesmaynotbecoincidental.Becauseoftheslightlydeficitirrigation,veryfewdrainageeventsoccurredforeachcalculationperiodatMurray;thusanyabnormaldrainagehadasignificanteffectonthecalculatedcropcoefficient.Thiswasevidentin2005,wherethecalculatedKcvaluesareconsiderablyhigherthanthevaluescalculatedforotheryears.Drainageadjustmentsweremadein2006and2007onbothlysimeters.

30

Southgate

EvapotranspirationestimatedfromwaterbalancevaluesatSouthgatevariedfrom19.7(2006)to40.2inches(2007)fortheEastlysimeterandfrom23.1(2006)to50.0inches(2007)ontheWest(Table13).CalculatedETrsforSouthgatevariedfrom36.9to74.7inches.EstimatedKcfortheEastlysimetervariedfrom0.48to0.55,witha5‐yearaverageof0.53.TheWestlysimeterKcwassomewhathigher,varyingfrom0.63to0.67,witha5‐yearaverageof0.65.AverageKcforallyearsoverbothlysimeterswas0.59.Drainageadjustmentsweremadeeveryyearexcept2006ontheEastlysimeterand2004ontheWest.Forreasonsthatarenotclear,ETontheWestlysimeterwassignificantlyhigherthanontheEast.Thusthe5‐yearaverageKc,0.53,fortheEastlysimeterisabout18%lowerthantheWestlysimeter’saverageKcof0.65.TheWestlysimeteraverageKcvalueof0.65forturfgrass,isabout16%higherthanthepreviouslyusedvalueof0.56(Hill,1994).TABLE13:SOUTHGATEGOLFCOURSEEASTANDWESTLYSIMETERFULLSEASONWATERBALANCEVALUESWITH

SEASONALCALCULATEDCROPCOEFFICIENTSEastLysimeter

Calc.PeriodYear

Begin End

Irrig.+Rain(in)

WaterAdded(in)

MeasuredDrain.(in)

AdjustedDrain.(in)

ET(in)

ETrs(in)

Kc

2004 11‐Jun 4‐Dec 35.71 0 13.70 13.98 21.73 41.29 0.532005 10‐Mar 2‐Dec 33.22 13.59 3.33 12.18 34.63 63.38 0.552006 23‐Jun 1‐Dec 23.81 0 4.13 4.13 19.68 36.59 0.542007 24‐Jan 29‐Dec 54.97 2.60 15.22 17.35 40.22 74.73 0.542008 7‐Feb 18‐Nov 46.58 0.00 12.54 13.16 33.42 69.14 0.48

AverageKc= 0.53


Calc.PeriodYear

Begin End

Irrig.+Rain(in)

WaterAdded(in)

MeasuredDrain.(in)

AdjustedDrain.(in)

ET(in)

ETrs(in)

Kc

2004 11‐Jun 4‐Dec 36.83 0 9.28 9.28 27.55 41.29 0.672005 10‐Mar 2‐Dec 41.91 7.81 10.23 9.47 40.25 63.38 0.642006 23‐Jun 1‐Dec 31.50 0 7.08 8.43 23.07 36.59 0.632007 24‐Jan 29‐Dec 69.48 1.73 19.51 21.17 50.04 74.73 0.672008 7‐Feb 18‐Nov 62.22 0 17.03 17.9 44.32 69.14 0.64

AverageKc= 0.65

KcSt.Dev.= 0.02



31

SpanishFork

TheSpanishForkNorthlysimeterETvariedfrom17.8(2002)to30.4inches(2004),asgiveninTable14.CalculatedETrsvariedfrom31.7to49.7inches.TheobservedKcfortheNorthlysimetervariedfrom0.51to0.63,witha5‐yearaverageof0.58.TheSouthlysimeterETwasaboutthesameasthatfortheNorthvaryingfrom14.2(2002)to29.9inches(2005).TheobservedKcvariedfrom0.45to0.61,witha5‐yearaverageof0.54.TheaverageKcforallyearsoverbothlysimeterswas0.56,whichisidenticaltothevaluepreviouslyused.NodrainageadjustmentswereneededforeitherlysimeteratSpanishFork.TABLE14:SPANISHFORKTURFPLOTNORTHANDSOUTHLYSIMETERFULLSEASONWATERBALANCEVALUESWITH

SEASONALCALCULATEDCROPCOEFFICIENTSNorthLysimeter

Calc.PeriodYear

Begin End

Irrig.+Rain(in)

WaterAdded(in)

MeasuredDrain.(in)

AdjustedDrain.(in)

ET(in)

ETrs(in)

Kc

2002 5‐Jun 3‐Oct 18.73 0 0.96 0.96 17.77 31.67 0.562003 30‐Apr 10‐Nov 20.35 4.62 2.29 2.29 22.68 44.87 0.512004 1‐Apr 10‐Nov 34.16 6.13 9.90 9.90 30.39 48.33 0.632005 22‐Mar 2‐Nov 40.28 4.01 14.90 14.90 29.39 49.72 0.592006 24‐Apr 11‐Oct 32.13 6.48 10.15 10.15 28.46 45.35 0.63

AverageKc= 0.58

SouthLysimeter KcSt.Dev.= 0.05

Calc.PeriodYear

Begin End

Irrig.+Rain(in)

WaterAdded(in)

MeasuredDrain.(in)

AdjustedDrain.(in)

ET(in)

ETrs(in)

Kc

2002 5‐Jun 3‐Oct 19.54 0 5.38 5.38 14.16 31.67 0.452003 30‐Apr 10‐Nov 22.93 4.62 5.09 5.09 22.46 44.87 0.502004 1‐Apr 10‐Nov 34.52 6.44 11.61 11.61 29.35 48.33 0.612005 22‐Mar 2‐Nov 35.04 6.18 11.35 11.35 29.87 49.72 0.602006 24‐Apr 11‐Oct 31.84 5.76 13.20 13.20 24.40 45.35 0.54

AverageKc= 0.54

KcSt.Dev.= 0.07



32

Sunbrook

WateruseontheSunbrookEastlysimetervariedfrom13(2004)to35.9inches(2005)andKcvariedfrom0.37to0.68,witha5‐yearaverageof0.49(Table15).TheWestlysimeterETwassimilar,varyingfrom13.8(2004)to35.5inches(2002).CalculatedKcvariedfrom0.33to0.64,witha5‐yearaverageof0.46.TheaverageKcforallyearsoverbothlysimeterswas0.47.TheserelativelylowKcvaluesmayreflectthedatacollectionissuesexperiencedatthissite.CalculatedETrsforSunbrookvariedfrom29.7to71.3inches.Thiswiderangecorrespondstothevariableseasonlengthfromyeartoyear.Drainageadjustmentsweremadein2005onbothlysimeters.ThehighestKcvalues(0.68and0.64)werederivedfortherelativelyshortcalculationperiod,lateJunethroughmid‐October,2006.TheaveragetwolysimeterKcvalueof0.66forthis21/2monthperiodisessentiallythesameastheKc(0.65)fromtheSouthgateWestlysimeter(Table13).TABLE15:SUNBROOKGOLFCOURSEEASTANDWESTLYSIMETERFULLSEASONWATERBALANCEVALUESWITH

SEASONALCALCULATEDCROPCOEFFICIENTSEastLysimeter

Calc.PeriodYear

Begin End

Irrig.+Rain(in)

WaterAdded(in)

MeasuredDrain.(in)

AdjustedDrain.(in)

ET(in)

ETrs(in)

Kc

2002 25‐Feb 5‐Nov 35.12 0 0 0 35.12 71.33 0.492003 3‐Feb 10‐Nov 31.28 0 1.06 1.06 30.22 71.07 0.432004 1‐Mar 29‐Jun 13.6 0 0.62 0.62 12.98 35.17 0.372005 18‐Jan 28‐Dec 39.93 6.5 5.02 10.54 35.89 70.69 0.512006 26‐Jun 16‐Oct 25.44 0 5.34 5.34 20.10 29.73 0.68

AverageKc= 0.49


Calc.PeriodYear

Begin End

Irrig.+Rain(in)

WaterAdded(in)

MeasuredDrain.(in)

AdjustedDrain.(in)

ET(in)

ETrs(in)

Kc

2002 25‐Feb 5‐Nov 35.46 0 0 0 35.46 71.33 0.502003 3‐Feb 10‐Nov 24.99 0 1.49 1.49 23.50 71.07 0.332004 1‐Mar 29‐Jun 13.78 0 0 0 13.78 35.17 0.392005 18‐Jan 28‐Dec 31.98 6.07 5.00 8.29 29.76 70.69 0.422006 26‐Jun 16‐Oct 23.50 0 4.62 4.62 18.88 29.73 0.64

AverageKc= 0.46

KcSt.Dev.= 0.12



33

ESTIMATEDMONTHLYTURFGRASSCROPCOEFFICIENTSDerivingKcrvaluesforshorterthanseasonaltimeperiodsresultedinpoorresultsduetothetemporalresolutionofthelysimeterdata(seepage23herein).However,attherequestoftheUtahDivisionofWaterResources,monthlyKcr,andsubsequentlyKco,valueswerecalculatedforfourofthelysimeters:Logan–New,SpanishFork–North,andbothSouthgatelysimeters.DatanearthebeginningandendofeachmonthwereadjustedinanattempttoattributemeasuredETtothecorrectmonth.Forexample:ifalysimeterreadingwasmadewithinthefirstfewdaysofthemonthandnoreadingwasmadeonthelastdayortwoofthepreviousmonththedatawasproratedbetweenthe2monthsusingthenumberofdaysinthemeasurementinterval.FurtheradjustmentsweremadetothedatauponfinalanalysisbydiscardingobviousoutliersfromtheaveragemonthlyKcvalues.AlfalfaReference,ETrs,BasedCropCoefficientsTheyear‐to‐yearvariationinmonthlyKcrvaluesatthefourlysimetersisshowninFigures10through13.Althoughtherewasconsiderabledeviationinsomepoints(“outliers”),i.e.November2006,LoganNew(Fig.10);September2002and2003andMarch2005,SpanishForkNorth(Fig.11);December2006,SouthgateEast(Fig.12)andDecember2004,SouthgateWest(Fig.13),therewasgeneralagreementintrendsduringtheseason.

FIGURE10.MONTHLYKCRVALUESFORTHELOGANNEWLYSIMETER,2004‐2008

34

FIGURE11.MONTHLYKCVALUESFORTHESPANISHFORKNORTHLYSIMETER,2002‐2006.

FIGURE12.MONTHLYKCVALUESFORTHESOUTHGATEEASTLYSIMETER,2004‐2008.

35

FIGURE13.MONTHLYKCVALUESFORTHESOUTHGATEWESTLYSIMETER,2004‐2008.AverageKcrvaluesforeachmonthatthefourlysimetersareshowninFigures14through17.ThedashedlinesinthefiguresrepresenttheseasonalsuggestedKcrvaluesforthelocation.SeasonalKcrvalueswere0.6forLoganandSpanishForkand0.65forSouthgate.TheoutlyingdatapointswerenotincludedinFigures14through17.

FIGURE14.AVERAGEKCVALUESFOREACHMONTHFORTHELOGANNEWLYSIMETER..OBVIOUSOUTLIERSWERE

EXCLUDED.THEDASHEDLINEREPRESENTSTHESUGGESTEDFULLSEASONKCR.

36

FIGURE15.AVERAGEKCVALUESFOREACHMONTHFORTHESPANISHFORKNORTHLYSIMETER.OBVIOUS

OUTLIERSWEREEXCLUDED.THEDASHEDLINEREPRESENTSTHESUGGESTEDFULLSEASONKCR.

FIGURE16.AVERAGEKCVALUESFOREACHMONTHFORTHESOUTHGATEEASTLYSIMETER.OBVIOUSOUTLIERS

WEREEXCLUDED.THEDASHEDLINEREPRESENTSTHESUGGESTEDFULLSEASONKCR.

37

FIGURE17.AVERAGEKCVALUESFOREACHMONTHFORTHESOUTHGATEWESTLYSIMETER.OBVIOUSOUTLIERS

WEREEXCLUDED.THEDASHEDLINEREPRESENTSTHESUGGESTEDFULLSEASONKCR.

ThevaluesinFigures14and15werecombinedtoobtainanaverageforthehigherelevationregionsofthestate.TheresultsofthiscomparisonalongwithasuggestedseasonallyvaryingcropcoefficientcurveareshowninFigure18.Asimilarcurve,Figure19,wasdevelopedforthelowelevationsouthernregionofthestate.

FIGURE18.SUGGESTEDKCCURVEFORTHEHIGHERELEVATIONAREASOFUTAH.MONTHLYKCVALUESAVERAGED

BETWEENTHELOGANNEWANDSPANISHFORKNORTHLYSIMETERS.OBVIOUSOUTLIERSWEREEXCLUDED.

38

FIGURE19.SUGGESTEDKCCURVEFORTHELOWELEVATIONAREASOFSOUTHERNUTAH.MONTHLYKCVALUES

AVERAGEDBETWEENTHETWOSOUTHGATELYSIMETERS.OBVIOUSOUTLIERSWEREEXCLUDED.ThecropcoefficientsshowninFigures18and19arereasonableKcrcurvesfordifferentregionsofUtah.ThecurveinFigure18representsthemajorityofthestate(excepttheSouthernLowelevationregionofUtah’sDixie).ThecurvesuggestedinFigure18beginswithavalueof0.45startingatturfgreenuporabsenceofsnowinthespring(aroundthebeginningtomiddleofMarchformanyareas).TheKcrremainsat0.45forabout20daysuntillateMarchwhentheturfbeginsactivegrowth.TheKcrvaluethenincreaseslinearlyforabout30daystoavalueof0.60whentheturfreachesfullleafareaandgrowth(typicallyneartheendofApril).TheturfKcrremainsat0.60forthedurationoftheseasonuntilcoolfalltemperaturesresultinreducedturfgrowthrates.Thisistypicallyaroundmid‐October,afterwhichKcrdecreaseslinearlytoward0.45inearlyNovemberandremainsatthatvalueuntildormancy.TheKcrcurveforUtah’sDixie,Figure19,issimilartothatofFigure18,however,itcontinuesforthefullyearandisshiftedupbyabout0.05.TheKcrbeginsinJanuaryatavalueof0.50duringthesemi‐dormantperiod.InlateFebruarytoearlyMarchtheKcrvaluebeginstoincreaselinearlytowardavalueof0.65,typicallyreachedafterabout30daysorwithinthefirstweekofApril.TheKcrvalueremainsat0.65forthemajorityoftheseasonuntilthegrowthslowsinlatefall.ThisoccursinmidtolateOctoberandtheKcrvaluedecreaseslinearlytowardavalueof0.50,whichistypicallyreachedinmid‐November,andremainsat0.50untilthefollowingspring.Inbothsetsofsuggestedcropcoefficientcurves,Figures18and19,maintainingthemid‐seasonKcrataconstantvalue,0.60or0.65,ignorestheindicationofa“summerslump”inturfwateruse.

39

GrassReference,ETos,CropCoefficients

CalculatedvaluesofETforagrassreference,EToarelowerthanthoseforanalfalfareferenceby10to25%orso(Jensen,etal.,1990).Asaresult,grassreferencebasedcropcoefficient,Kco,valuesarecorrespondinglygreaterthanalfalfabasedcropcoefficients,Kcr.Typically,multiplicationfactorsonETorangingfrom1.15to1.25havebeenusedtoapproximateETr(forexample,ETr=1.2ETo).ThecropcoefficientvaluesforETrspresentedaboveshouldbemultipliedbyafactorapproximatelyequalto1.2torelatetoanASCEStandardizedgrassreference,ETos,basis.Thus,themid‐seasonKcovaluesare0.72(0.72=1.2x0.6)forhigherelevationsandnorthernUtah.Similarly,amid‐seasonKcovalueof0.78(0.78=1.2x0.65)wouldbeindicatedforthesouthernandlowerelevationpartsofthestate.TheearlyandlateseasonKcovaluesbecome0.48and0.60,respectively,forthenorthernhigherelevationandsouthernlowerelevationsites.Mid‐seasonKcovaluesof0.70fornorthernUtahandhigherelevationsand0.80forsouthernUtahandlowerelevationsareobtainedfromroundingthesevaluestothenearest0.05.CorrespondingearlyandlateseasonKcovaluesare0.50and0.60,respectively,forthenorthernhigherelevationandsouthernlowerelevationsites.TheresultingcropcoefficientcurvesareshowninFigures20and21.

FIGURE20.SUGGESTEDKCOCURVEFORTHEHIGHERELEVATIONAREASOFUTAHALONGWITHKCOVALUESFOR

EACHMONTHAVERAGEDBETWEENTHELOGANNEWANDSPANISHFORKNORTHLYSIMETERS.ADAPTEDFROM

FIGURE18.

40

FIGURE21.SUGGESTEDKCOCURVEFORTHELOWELEVATIONAREASOFSOUTHERNUTAHALONGWITHKCO

VALUESFOREACHMONTHAVERAGEDBETWEENTHETWOSOUTHGATELYSIMETERS.ADAPTEDFROMFIGURE19.

41

SUMMARYANDCONCLUSIONSObservedseasonalturfgrassconsumptiveusevariedfrom11.2inches(LoganWest,2004,Table11)to50.0inches(Southgate,2007,Table13).TherangeatLogan(Table11)was11.2(West,2004)to35.2inches(New,2007);atMurray(Table12),22.2(East,2008)to30.5inches(East,2005);atSouthgate(Table13),19.7(East,2006)to50.0inches(West,2007);atSpanishFork(Table14),14.2(South,2002)to30.4inches(North,2004)and13.0(East,2004)to35.5inches(West,2002)atSunbrook(Table15).DirectcomparisonofsuchvariationinETvaluesacrossyearsandsitesisproblematicduetodifferinggrowingseasonlengthsfromyeartoyear,siteenvironmentalconditions(averagetemperaturesandwindpatterns),andelevation(rangeof2600to4800ftabovemsl)fromsouthtonorthinUtah(Latituderangeof37°Nto42°N).Therewasconsiderableyeartoyearandlysimetertolysimetervariation.TheyeartoyearvariationwasmoreevidentatSouthgateandSunbrook,dueperhapstothelargervariationincalculationperiodsthanattheothersites.ThelysimetertolysimetervariationwasparticularlynoticeableatLogancomparingtheWestlysimetertoboththeNewandtheEastlysimeters.TherewasalsoafairdifferencebetweenthetwolysimetersatSouthgate.ThevariationinrainplusirrigationthatisevidentinTables11‐15betweenlysimetersatagivensiteillustratesnon‐uniformityofirrigationasthereisproportionatelylesservariationinthemagnitudeofrainamounts.Itwasalsoaperplexingdataanalysisissue.Themulti‐yearaverageseasonalobserved(basedonlyonindividuallysimeterET)cropcoefficientvaluesvariedfrom0.34(LoganWest)to0.65(SouthgateWest).SingleseasonKcvaluesof0.74and0.70werecalculated,respectively,fortheEastandWestMurraylysimetersin2005,buttheseseemanomalousandmaybeduetodrainagemeasurementproblems.Ashortperiod,2‐1/2month,lysimeteraverageKcof0.68wasobtainedatSunbrookEast(2006).StudyperiodaverageseasonalKcvaluesbylysimeterwere:Logan0.59(New),0.42(East),0.34(West)andsiteaverageof0.45;Murray0.57(bothEastandWest)andsiteaverageof0.57;Southgate0.53(East),0.65(West)andsiteaverageof0.59;SpanishFork0.58(North),0.54(South)andsiteaverageof0.56andSunbrook0.49(East),0.46(West)andsiteaverageof0.47.AveragetwolysimeterseasonalKcvaluesatMurrayandSpanishForkweresimilar(0.57and0.56,respectively)althoughtherewaslessacrossyearvariationatSpanishFork.IgnoringtheolderlysimetersatLogan,the5‐yearseasonalaverageKcrontheNewlysimeterofabout0.60mayreasonablyrepresentawell‐wateredturfgrass,cuttingheightof1.5to2inches,inthecentralandnorthernpartsofthestate,whereastheSouthgateWestlysimeter5‐yearseasonalaverageKcrof0.65wouldsimilarlybereasonabletouseinthelowerelevationandwarmersouthernUtah.TheseKctvalues,0.60and0.65,are,respectively,about7%and16%higherthantheKcof0.56usedinearlierestimatesofturfgrassevapotranspirationacrossUtah(Hill,1994).

42

FurtheranalysiswasconductedtoderivemonthlyKcrandsubsequentlyKco,valuesforfourofthelysimeters:Logan–New,SpanishFork–North,andbothSouthgatelysimeters.LysimeterETdatanearthebeginningandendofeachmonthwereproratedbetweenthe2monthsusingthenumberofdaysinthemeasurementinterval.FurtherdataadjustmentsweremadeuponfinalanalysisbydiscardingobviousoutliersfromtheaveragemonthlyKcvaluesTheturfgrasscropcoefficientforthemajorityofthestate(exceptlowelevationsouthernUtah)beginswithavalueof0.45startingatturfgreenuporabsenceofsnowinthespring(aroundthebeginningtomiddleofMarchformanyareas).TheKcrremainsat0.45forabout20daysuntillateMarchwhentheturfbeginsactivegrowth.TheKcrvaluethenincreaseslinearlyforabout30daystoavalueof0.60whentheturfreachesfullleafareaandgrowth(typicallyneartheendofApril).TheturfKcrremainsat0.60forthedurationoftheseasonuntilcoolfalltemperaturesresultinreducedturfgrowthrates.Thisistypicallyaroundmid‐October,afterwhichKcrdecreaseslinearlytoward0.45inearlyNovemberandremainsatthatvalueuntildormancy.TheKcrcurveforUtah’sDixieissimilar;however,itcontinuesforthefullyearandisshiftedupbyabout0.05.TheKcrbeginsinJanuaryatavalueof0.50duringthesemi‐dormantperiod.InlateFebruarytoearlyMarchtheKcrvaluebeginstoincreaselinearlytowardavalueof0.65,typicallyreachedafterabout30daysorwithinthefirstweekofApril.TheKcrvalueremainsat0.65forthemajorityoftheseasonuntilthegrowthslowsinlatefall.ThisoccursinmidtolateOctoberandtheKcrvaluedecreaseslinearlytowardavalueof0.50whichistypicallyreachedinmid‐Novemberandremainsat0.50untilthefollowingspring.Inbothsetsofsuggestedcropcoefficientcurves,maintainingthemid‐seasonKcrataconstantvalue,0.60or0.65,ignorestheindicationofa“summerslump”inturfwateruse.Grassreference‐basedcropcoefficient,Kco,valueswerederivedfromKcrbymultiplyingKcrbyabout1.2.Thus,themid‐seasonKcovaluesare0.72(0.72=1.2x0.6)forhigherelevationsandnorthernUtah.Similarly,amid‐seasonKcovalueof0.78(0.78=1.2x0.65)wouldbeindicatedforthesouthernandlowerelevationpartsofthestate.TheearlyandlateseasonKcovaluesbecome0.48and0.60,respectively,forthenorthernhigherelevationandsouthernlowerelevationsites.Mid‐seasonKcovaluesof0.70fornorthernUtahandhigherelevationsand0.80forsouthernUtahandlowerelevationsareobtainedfromroundingthesevaluestothenearest0.05.CorrespondingearlyandlateseasonKcovaluesare0.50and0.60,respectively,forthenorthernhigherelevationandsouthernlowerelevationsites.

43

REFERENCESAllen,R.G.,J.PruegerandR.W.Hill.1992.Evapotranspirationfromisolatedstandsof

hydropytes:cattailandbulrush.Trans.ASAE35(4):1191‐1198.Allen,R.G.andJ.L.Wright.2002.ConversionofWright(1981)andWright(1982)alfalfa‐based

cropcoefficientsforusewiththeASCEStandardizedPenman‐MonteithReferenceEvapotranspirationEquation.TechnicalNote.USDA‐ARSKimberly,ID.December.

Allen,R.G.,I.A.Walter,R.Elliot,T.A.Howell,D.ItenfisuandM.E.Jensen.2005.TheASCE

StandardizedReferenceEvapotranspirationEquation.TaskCom.onStandardizationofReferenceEvapotranspiration,EWRI,ASCE.Reston,VA.

Dlamini,M.V.D.2003.Short‐TermWaterUseDynamicsinDrainageLysimeters.Unpublished

PhDDissertation.UtahStateUniversity,Logan,UtahErvin,E.H.andA.J.Koski.1998.DroughtAvoidanceAspectsandCropCoefficientsofKentucky

BluegrassandTallFescueTurfsintheSemiaridWest.CropScience38:788‐795.Hill,R.W.,C.E.Brockway,R.D.Burman,L.N.AllenandC.W.Robison.1989.DutyofWater

UndertheBearRiverCompact:FieldVerificationofEmpiricalMethodsforEstimatingDepletion.FinalReport.UtahAgricultureExperimentStationResearchReportNo.125.UtahStateUniversity,Logan,Utah.January.

Hill,R.W.1994.ConsumptiveuseofirrigatedcropsinUtah,UtahAgriculturalExperiment

StationResearchReportNo.145,UtahStateUniversity,Logan,UT,Oct.370p.RevisedFeb.1997,reprinted.AlsoonplacedontheWebathttp://nrwrtl.nr.state.ut.us/techinfo/consumpt/default.htm

Hill,R.W.,A.Gonzalez‐Mesa,L.N.Allen,andR.Oldham.1997.Turfgrasswateruseforan

IntermountainGolfCourse.PresentedattheSep.18‐20,PNWRegionMeeting,PaperNo.PNW97‐108,ASAE2950NileRoad,St.Joseph,MI49085‐9659.

Jensen,J.E.,R.D.BurmanandR.G.Allen(Eds.)1990.EvapotranspirationandIrrigationWater

Requirements.AmericanSocietyofCivilEngineers,345East47thStreet,NewYork,NY10017‐2398.ASCEManualNo.70.

Quinlan,P.,R.BurmanandE.Siemer.1982.Insitulysimeterinstallation.ASAETech.Paper82‐

2015.AmericanSocietyofAgriculturalEngineers,St.Joseph,MI.

Wright,J.L.1982.NewEvapotranspirationCropCoefficients.JournalOfIrrigationAndDrainageDivision.ASCE,Vol.108,pp.57‐75.

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Wright,J.L.,R.G.Allen,T.A.Howell.2000.ComparisonBetweenEvapotranspirationReferencesandMethods.pages251‐259inEvans,R.G.,B.L.Benham,andT.P.Trooien(ed.)ProceedingsoftheNationalIrrigationSymposium.ASAE,Nov.14‐16,2000,Phoenix,AZ.

45

APPENDICESAPPENDIXA:WorkTasksbyObjective

A.Determineturfgrasswaterusebymeasurementwithlysimeters.

USU:1.Arrangeforfabricationandtransportlysimeterseachsite.2. Superviseinstallationoflysimetersateachsiteandprovideoverallsupervisionof

project.3. Trainpersonnelateachsiteinirrigationprecipitation,weather,andlysimeterdata

collectionanddatatransferprotocol.4. Receiveweeklye‐mailedlysimeterdatareportsfromeachsite,enterintospreadsheet

andperformpreliminaryqualitycontrolanalysis.5. Performweeklypreliminarydataanalysisforqualitycontrolforallsites,collect

lysimeterandweatherdataatLogansite.6. Prepareannualprogressreports.Analyzeavailableweatherdatafromelectronic

weatherstationsandassociatedNWSstationsandprepareconsistentdailyandmonthlydatasetsandshareinterimresultsasappropriate.

7. Provideongoingtrainingandsupervisionasneeded.8. PerformdetailedanalysisoffirsttwoyearsoflysimeterdataafterNovember2002and

prepareinterimturfgrasscropcoefficientandwateruserecommendations.9. PreparefinalreportsummarizingthelysimeterdatafromCacheValley,southSaltLake

County,UtahCounty,andWashingtonCounty.

BYU:1.PerformlysimeterdatacollectionatBYUturfplotsbeginninginearlyMarchand

continuingthroughNovember.Thefrequencyshouldbeatleastonceperweekinspringandfallandtwice(orthreetimes)perweekinthesummer.

2. Collectothersitedataasappropriate(seeAnnex).3. E‐mailcurrentdatatoUSUeachweek.4. Reviewreports,providesuggestionsforimprovement.

B. Analysisofpreviouslycollectedturfgrassirrigationandsoilwatercontentdata.

BYU:1. Locateandorganizearchiveddata.2. Transmitinelectronicformat(standardDOS‐ASCIIorExcelorQuattro)toUSUBIE

personnel.3. Reviewpreliminaryresultsanddraftoffinalreport.

USU:1. Review,screen,andperformdetailedanalysisofneutronprobe,irrigation,

precipitation,andweatherdataasreceivedfromBYU.2. Preparesummaryreportoffindings.

46

APPENDIXB:TurfLysimeterDataCollectionProtocolThepurposeofthisprotocolistoformalizeturfgrasslysimeterdatacollectionprocedures.Thiswillaidinobtainingturfgrasswateruseunderwell‐wateredconditions.Well‐wateredconditionsareassuredonlyifdrainageoccursfromtimetotime.I. DataCollectionProcedureandObservations

A. Raingage

Theraingagetopfunnelshouldberemoved.Theinnermeasurementcylindershouldbetakenoutandheldupsuchthatthewatersurfaceisateyelevel.Theamountofwater(hundredthsofinches)shouldberecordedonthedatasheet.Ifmorethan1inchofirrigationandprecipitationoccurs,theinnercylindershouldbedumped(equals1inchatoverflow),andwaterpouredintoitfromtheraingagetogetthereading.Thetotaldepthshouldberecordedonthedatasheet.

B. DrainageBucket Thebucketshouldberemovedfromthemanholewell,andsetonalevelsurface

(perhapsthemanholelid).Thedepthofwatershouldbemeasuredwithatapemeasuretothenearest1/16inchintwodiametricallyoppositesidesofthebucket(toallowfornon‐level).Thetwodepths(h1,h2)shouldberecordedonthedatasheet.Alternately,agraduatedcylindercouldbeusedtoobtainwatervolumesinplaceofthetwodepthmeasurements.

C. DataSheet

EastLysimeter WestLysimeter Date

RainGageDepth Drainagebucketdepth(inch)

RainGageDepth Drainagebucketdepth(inch)

NW(inch)

SE(inch) h1,h2 Avg NW(inch) SE(inch) h1,h2 Avg

Comments

47

D. DataCollectionInterval.

Datashouldbecollectedfromtheraingagesanddrainagebucketforeachlysimeteratleastonceperweek.However,ifthedrainagebucketsareallowedtooverflow,thewaterbalancemeasurementwillbelostforthattimeperiod.Thus,thelysimeterdatacollectionintervalmayneedtobe2or3days,ratherthanonceperweek,ifabundantdrainageisoccurringormayoccurduetoheavyrainorirrigation.

Atthetimeofdatacollection,cleananygrassleavesthatmaybeencroachingontheraingageouterpipes.Also,noteanyconditionsthatmayaffectdataaccuracy.

II. SpringtimeDataCollectionInitiation(exceptatSt.George,whichisyearround) Assoonasthesnowhasmelted,theraingagesshouldbecleanedandplacedinanuprightpositionwiththetopasclosetolevelaspossibleandabout1inchbelowthegroundsurface.Anygrassshouldbetrimmedawayfromtheinsideofraingageaccesspipe(6inchPVC).Thedrainagebucketsshouldalsobeplacedunderthedrainpipe.Thedateandtimeofstart‐upshouldberecordedandfaxed[(435)797‐1248]ore‐mailed([email protected])toR.W.Hill. Withinadayortwo,checkthedrainagebucketforanydrainagewater.Ifnodrainageoccurs,thenameasuredquantityofwater(15gallons)shouldbeaddedtoeachlysimeter.Ifthesoilismoist,thedrainagebucketsshouldbecheckedin30minutes.Anydrainageshouldbenotedandmeasuredifmorethan1/3full,andthebucketsemptied.Usejudgmenttoestimatewhenthebucketsshouldbecheckedagaintoavoidoverflow.III. GrowingSeasonObservations Weeklylysimeterdatacollectionvisitsshouldbegininthespringandcontinuethroughoutthesummerandfall.Dependingontheamountofdrainage,thevisitsmayneedtobetwiceweeklytoavoidhavingadrainagebucketoverflowinbetweenobservations.Ateachvisit,datashouldbecollectedasdescribedinSectionI.Thedatasheetshouldbefaxedto[(435)797‐1248]toR.W.Hill,every2or3weeks. Itisimportanttothepurposeofthestudythatadequatewaterbeappliedtothelysimeters.Thus,somedrainageisnecessarytoensure“well‐watered”conditionshavebeenrealized.Ifdrainageisnotoccurringeachweek,thentheadditionofextrawatertoeachlysimetermustbedone.Ifnodrainageoccurs,thenameasuredquantityofwater(15gallons)shouldbeaddedtoeachlysimeter.Ifthesoilismoist,thedrainagebucketsshouldbecheckedin30minutes.Anydrainageshouldbenotedandmeasuredifmorethan1/3full,andthebucketsemptied.Usejudgmenttoestimatewhenthebucketsshouldbecheckedagaintoavoidoverflow.Also,thisprocedureshouldbefollowedtoinducedrainageattheendofeachmonth(April,May,June,July,AugustandSeptember)ifnootherdrainagehasoccurred.

48

IV. WinterShutDown(exceptatSt.George) Theraingageshouldbeturnedupsidedown,orremovedfromthefield,whentemperaturesbecomecoldenoughtocausefreezingdamage.Themeasurementshouldbediscontinuedifsignificantsnowfalloccurs.Thedrainagebucketscouldbeleftinplacealittlelonger,withoutfrostdamage.Although,theyeventuallyshouldalsobeturnedupsidedownwhenairtemperaturesdropbelowabout20°F.

49

APPENDIXC:WeatherStationSensorsandObservationParametersEachelectronicweatherstationincludedaCampbellScientificdatalogger(CR10XatLogan,Murray,SouthgateandSunbrookandCR10atSpanishFork)andthefollowingsensors:

• TwoCampbellScientific107TemperatureProbes,oneforairandoneforsoiltemperature

• VaisalaHMP45CRelativeHumidityProbe• LICORLI200sSiliconPyranometer,forsolarradiation• MetOne014AAnemometerandMetOne024AWindDirectionSensor(atLogan,

MurrayandSpanishFork)orRMYoung05103WindMonitor(atSunbrookandSouthgate),forwindspeedandwinddirection

Thedataloggerscannedthevariousinputsensorsonceevery10seconds.Theseobservationswereprocessedandoutputasdaily(midnighttomidnight)andhourlyvalues.Theparametersoutputeachhourandeach24hourperiodwere:

Hourly• Averageairtemperature• Maximumairtemperature• Minimumairtemperature• Averagerelativehumidity• Totalsolarradiation• Averagewindspeed• Averagewinddirection• Averagesoiltemperature

24Hour(oncedaily)Output

• Maximumairtemperature• Minimumairtemperature• Maximumrelativehumidity• Minimumrelativehumidity• Totalsolarradiation• Totalwindrun• Averagewinddirection• Averagesoiltemperature

50

APPENDIXD:SummaryofDataCollectedatLogan,1991‐2001TABLED1:SEASONALTOTALIRRIGATION,DRAINAGEANDTURFWATERUSE,1991‐95,2000‐01,FROMTWO

LYSIMETERSINTHELOGANGOLFANDCOUNTRYCLUB,LOGAN,UTAH.PARTIALSEASONDATAFOR1996‐99 EastLysimeter WestLysimeter

Year SeasonIrrigation+rain,in

Drainagein

ETin

Irrigation+rain,in

Drainagein

ETin

AverageET,

inches

1991 03Apr‐28Oct 38.95 6.81 32.14 38.00 13.94 24.06 28.101992 15Apr‐27Oct 28.29 0.18 28.11 28.69 2.97 25.72 26.921993 16Apr‐26Oct 30.77 6.36 24.41 34.87 15.75 19.12 21.771994 11Apr‐28Oct 35.08 3.94 31.14 37.80 14.71 23.08 27.101995 17Apr‐02Oct 27.48 1.59 25.89 32.17 11.06 21.11 23.502000 06Apr‐06Nov 35.70 2.11 33.59 32.73 8.67 24.06 28.832001 15Mar‐19Nov 44.24 11.39 32.84 42.08 20.64 21.44 27.14

SevenYearAverage 34.36 4.63 29.73 35.19 12.53 22.66 26.19

1996b 09May‐14Nov 25.93 3.75 22.18 27.64 8.46 19.18 20.681997b 09May‐03Dec 25.52 6.47 19.05 13.25 4.75 8.50 13.781998b 16Apr‐11Nov 22.61 2.87 19.74 15.91 5.39 10.52 15.131999b 11May‐08Sept 17.97 0.66 17.31 8.73 1.57 7.16 12.24

aThetwolysimetersarelocatedattheLoganGolfandCountryClubinaroughbetweentheholeoneandthreefairwaysandadjacenttothegreensnurseryarea.Theelectronicweatherstation(CampbellScientific,Inc.)iswestofthegreensnurseryandabout30feettothenorthoftheeastlysimeter.bSomedrainagerecordslostduetobucketoverflow.

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TABLED2:TURFGRASSWATERUSE(ET)ANDCROPCOEFFICIENTS(KCM),1991‐95,AND2000‐01,FROM

LYSIMETERSATTHELOGANGOLFANDCOUNTRYCLUB,LOGAN,UTAH.PARTIALSEASONDATAFOR1996‐99

EastLysimeter WestLysimeter

Year ETrInchesET,inches Kcm

ETrinches

ET,inches Kcm

SeasonalaverageKcm

1991 43.06 32.14 0.75 43.06 24.06 0.56 0.651992 48.82 28.11 0.58 48.82 25.72 0.53 0.551993 47.36 24.41 0.52 47.36 19.12 0.40 0.461994 52.00 31.14 0.60 52.00 23.08 0.44 0.521995 40.75 25.89 0.64 40.75 21.11 0.52 0.582000 48.37 33.59 0.69 48.37 24.06 0.50 0.602001 47.53 32.84 0.69 47.53 21.14 0.45 0.57SevenyearAverage 46.84 29.73 0.63 46.84 22.61 0.48 0.56 1996 33.90 22.18 0.65 32.91 19.18 0.58 0.621997 40.77 19.05 0.47 20.84 8.50 0.41 0.441998 28.56 19.74 0.69 21.70 10.52 0.49 0.591999 27.17 17.31 0.69 16.93 7.16 0.42 0.53ElevenYearAverage 0.63 0.48 0.56

1. WeatherDatafor1996wasobtainedfromLoganUSUStation2. 1995datastartedfromMayinsteadofApril3. For1996,97,98and1999somedrainagerecordslostduetobucketoverflow

52

APPENDIXE:CorrectionsMadetoWeatherData

Logan2002 Dailycalculationsonlyweredoneforthewholeyear,Day35hour1500appearstwicewith

differentdatathefirstwasdeleted.2003 Dailycalculationsonlyweredonefordays1–31,Day31valueswereerroneousexceptfor

maximumtemperature;allothervaluesweretakenasanaverageofDays30and32.2007 Day95hour1100wastakenasanaverageofhours1000and1200,Day304hours600and700

appearedtwicewithdifferentdatathesecond600andfirst700weredeleted.2008 Day86,hour600wasmissing(daylightsavingsshift)anaverageofhours500and700wasused

tocreatea600dataset.Day309hour900appearedtwice(daylightsavingsshift)tookaverageofbothlinesandusedit.

Murray2003 Dailycalculationsonlyweredonefordays1–30,Day30hadsomeerroneousvaluesfor

minimumtemperature,relativehumidity(maxandmin)andsolarradiation;thesevaluesweretakenasanaverageofdays29and30.

2004 Day336hour600datawasduplicated,oneoftheselineswasdeleted2005 Day303hour900appearedtwicewithdifferentdatathefirstwasdeleted.2006 Day42haderrorvaluesforminimumtemperatureandrelativehumidityassoiltemperature;

averagevaluesfromdays42and44wereused.OnDay100thedaywasfalselyincrementedupbyoneuntilDay103(whichappearedtwice)thiswascorrected.Thissameerrorwascorrectedbetweendays142and150.Day101hour2300wasestimatedasanaverageofhours2200and2400.

2007 Day333datawasreplacedwiththeaverageofDays332and334.2008 DatauptoDay25,hour600,was6hourdataduetoanaccidentalprogramalteration.Data

fromDay25,hour1500onwashourly,dailycalculationswereusedforDays1–25.DailywindandsolarradiationvaluesforDay25weretakenasanaverageofDays24and26,becausetheprogramchangecausedalossoftemporarydataintheloggeronDay25.Day72,hour600wasmissing(daylightsavingsshift)anaverageofhours500and700wasusedtocreatea600dataset.Day311hour700appearedtwice(daylightsavingsshift).Tookaverageofbothlinesandusedit.

Southgate2004 Day303hour900appearedtwicewithdifferentdata.Thefirstwasdeleted.2005 Day122hour800appearedidenticallytwice.Onewasdeleted,Day124hours600to800were

filledinwithdatafromSunbrook2006 Day67hour1600minimumtemperaturewasmissingthevaluefrom1700wasused.Hour1500

alldatawasmissingtheaveragesofvaluesfor1400andcorrectecd1600wereused.Dailyvalues(exceptmaximumairtemperature)weretakenasaveragesofdays66and69.Day93hour12wastakenasanaverageofhours1100and1300.

2008 Day70,hour700wasmissing(daylightsavingsshift)anaverageofhours600and800wasusedtocreatea700dataset.

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SpanishFork2002 Day61hour2100valuesweretakenasanaverageof2000and2200.Day16hour1000average

airtemperatureandrelativehumidityaswellasminimumairtemperatureweretakenasaveragesfrom800,900,1100,and1200.Day29hour1500averageairtemperatureandrelativehumidityaswellasminimumairtemperatureweretakenasaveragesfrom1300,1400,1600,and1700.Day122,hour1600valuesweretakenasanaverageof1500and1700.Day67hour200valuesweretakenasanaverageof100and300.Day136hour700valuesweretakenasanaverageof600and800.Day172,hour200valuesweretakenasanaverageof100and300.Day152,hour1500averageairtemperatureandrelativehumidityaswellasminimumairtemperatureweretakenasaveragesfrom1400and1600.Day189,hour1400wasrepeatedwithdifferentdatathesecondwasdeleted.Day207,hour200valuesweretakenasanaverageof100and300.Day223,hour200valuesweretakenasanaverageof100and300.Day241hour200valuesweretakenasanaverageof100and300.Day252hour1300wasrepeatedwithdifferentdata.Thesecondwasdeleted.

2003 Dailycalculationsonlyweredonefordays1–30.Fordays114to365,datawassavedeverytwohours,windwassavedasmph,thiswasmultipliedbytwotogetwindrunfor2hours.Day36dailyvaluesweretakenasanaverageofdays35and37,exceptmaximumrelativehumidity.Day113minimumdailyairtemperaturewastakenasanaverageofdays112and114.

2004 Alldatawassavedevery2hours.Windwassavedasmphandmultipliedby2togetwindrunfor2hours.

2005 DatauptoDay124wassavedevery2hours,windwassavedasmphandmultipliedby2togetwindrunfor2hours.Day31,hour1600toDay34weremissingaveragesfromdays28‐30and35‐37wereusedtofillinthedailygap.Day124minimumdailyairtemperatureandhumidityaswellassolarradiationandsoiltemperaturevalesweretakenasanaveragefromdays123and135.

2006 Replicadatabetweendays137and179wasdeleted.Sunbrook2002 Day98hour1200wastakenasanaverageofhours1100and1300.2003 Day28alldailyvaluesexceptmaximumairtemperatureandwind,weretakenasaveragesfrom

days27and29.Days175to179wereduplicated,aswereday189hour300today194hour1300,theduplicatesweredeleted.

2004 Day336minimumairtemperatureandrelativehumidityvaluesweretakenasaveragesofdays335and337.Day306hour600appearstwicewithdifferentdatathesecondlinewasdeleted.Day307hour600appearstwicewithdifferentdata.Thesecondlinewasdeleted.

2005 Somehourlyvaluesweren’tsavedfromdays1to28,dailycalculationsonly,weredoneforthisperiod.Day336hour900wasmissingminimumairtemperature,thevaluefrom800,wasused.Day76hour600appearstwicewithdifferentdata.Thesecondlinewasdeleted.

2006 Temperaturedatafromday252athour200today256athour1200andday257athour1200haderrors,thisdatawasreplacedwithdatafromSouthgate.

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APPENDIXF:AdjustmentsMadetoIndividualLysimeterDrainageValuesDuetoOvertopping

LoganThenew(East)lysimeterwasinstalledin2004withdatacollectionbeginninginearlyMay(Table9).Drainageadjustmentsweremadetothe2004and2005data.AtLoganthemaximumvolumethedrainagebucketscouldholdwasequivalentto0.81inchesofwaterappliedovertheareaofthelysimeter.OvertoppingeventsoccurredonSeptember3,2004,March28,2005,April28,2005,drainagefortheseeventswasadjustedto1.25,1.54,and1.74inches,respectively.AnovertoppingeventalsooccurredonJune10,2005,butthemodelshowedthatnochangewasnecessarysoitwasleftat0.81inches.DrainageadjustmentsfortheEastlysimeterweremadeforeveryyearexcept2004(Table10).Thedatesoftheovertoppingeventsandadjustmentsforthislysimeterin2002were:April30wasadjustedto1.00,June24to0.91,andSeptember,8to1.58.OnSeptember2,2003,anovertopeventwasestimatedtobe0.99inches,thiswasfoundbythemodeltobeanoverestimatesothedrainagewasadjustedto0.82inches.For2005anovertopeventonMarch25wasadjustedto1.65inches.Twoovertopeventswererecordedin2006,onJuly1andSeptember15.ThedrainageonJuly1wasnotadjusted,theother,however,wasadjustedto2.01inches.In2007twoadjustmentsweremade,oneonJune7to1.48inchesandoneonJuly26to1.06inches.AneventonJuly2,2007wasnotadjusted.AdjustmentsweremadeforallyearsfortheWestlysimeter(Table11).Inboth2002and2003theadjusteddrainagevaluesarelowerthanthereportedvaluesbecausebothyearshadlargenumbersofovertopevents,sevenin2002and5in2003.Inbothyearsfourvaluesdidnotneedadjusting,buthadbeenoverestimatedwhentheywereinitiallyrecorded.Thesevalueswerealladjustedto0.82inches.ThishappenedonJune7,14,and17andJuly15,2002,aswellasApril21,June14,August18and22,2003.Other2002overtopeventsoccurredApril30,June4,andSeptember8.Theseeventswereadjustedto1.58,0.92,and1.01inches,respectively.Oneeventwasadjustedin2003,onSeptember29.Itwaschangedto0.95inches.Twoovertopeventswereadjustedin2004,onMay13,adjustedto1.10inches,andSeptember3,adjustedto1.44inches.AneventonJuly16,2004wasnotadjusted.For2005,fiveeventswerenotadjusted,theyoccurredonJuly15and18,August29,andSeptember2and9.EventsonMarch28andApril28werechangedto1.69and1.95inches,respectively.DrainagevaluesforSeptember15andOctober8,2006wereadjustedto2.06and1.24inches.Fiveothereventsin2005on:May24and30,July25,August17,andSeptember20,werenotadjusted.Fourovertopeventsoccurredin2007,ofwhichtwowereadjusted.EventsonJune7andOctober9werechangedto1.53and1.16inches.TheothertwoeventsoccurredonJuly2and30.MurrayBecauseofdeficitirrigation,veryfewdrainageeventsoccurredforeachcalculationperiodatMurray;thusanyabnormaldrainagehadasignificanteffectonthecalculatedcropcoefficient.Thiswasthecasein2005,thereforeKcvaluesforthisyearareconsiderablyhigherthanvaluescalculatedforotheryears.

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Forbothlysimetersnodrainageadjustmentswereneededfortheyears2003through2005.However,adrainagebucketovertopeventoccurredonbothlysimetersonNovember4,2004.Theseeventswerenotadjustedandwereleftat0.97,theequivalentdepthoverthelysimetercorrespondingtothemaximumvolumewhichthedrainagebucketscouldhold.FortheEastlysimeter(Table12)adjustmentsweremadeforJun21,2007,changedto4.47inches,andJuly5,2007,changedto2.59inches.ThreeadjustmentsweremadetodrainagevaluesfortheWestlysimeteratMurray(Table13).ThefirstwasonJune21,2006,whichwasadjustedto1.31inches.AsecondoccurredonJuly5,2007,andwasadjustedto1.10inches.Thethirdevent,onJuly9,2007,mayhavebeenamissingdatavalue.Adrainagevalueof0.53incheswasaddedforthatdate.Southgate

DrainageadjustmentsweremadeeachyearforbothlysimetersatSouthgate(Tables14and15),withtheexceptionofEastlysimeterin2006.In2004overtopeventsoccurredtwiceattheEastlysimeter.OneoccurredonJune26,thiswasadjustedto1.04inches.TheothereventoccurredonOctober29;itwasnotadjustedbutwasleftat0.97,theequivalentdepthcorrespondingtoafulldrainagebucket.Twoovertopeventsoccurredin2005(September27andOctober24).Thefirstwasnotadjusted,butthesecondwaschangedto1.82inches.Duringthissameyearthemodelshowedsignificantdrainageonthreedays,forwhichtherecordshowednodrainage.Becausethereweresomeerrorsindatacollectiontheseanomaliesweretreatedasovertopevents.TheyoccurredonMay5,July21,andSeptember22;drainagevaluesof3.27,5.26,and3.74inches,respectively,wereuseddays.In2007fourovertopeventsoccurred,noadjustmentsweremadethefirsttwo,onJuly6andAugust29.TheothertwoeventswereonSeptember22,changedto1.45inches,andDecember2,changedto1.52inches.FortheWestlysimeteranovertopeventoccurredJune26,2004,on.Thedataforthiseventwasnotadjusted.AnovertopeventwasrecordedonOctober24,2005;thiswaschangedto2.25inches.In2005theWestlysimeterhadanomaliessimilartothosedescribedfortheEastlysimeter.TheyalsooccurredonMay5,June2,andJuly21.ThedrainageabnormalitiesinMayandJulywereadjustedto3.36and4.14inches,respectively.TheanomalyinJunewasnotadjusted.SpanishFork

NoovertopeventswererecordedforeitherlysimeteratSpanishForkforanyyear.Sunbrook

Adjustmentswereonlymadefor2005(SeeTables18and19).FortheEastlysimeterovertopeventsoccurredonFebruary28,August8,andSeptember18,2005.TheeventonFebruary28wasadjustedto4.19inchesandthatonSeptember18to1.07inches.TheeventinAugustwasnotchanged.Abnormalitieswerepresentinthe2005drainagerecordssimilartothosepresentatSouthgateforthesameyear.Theseoccasionswerealsotreatedasovertopeventsandwereadjustedaccordingly.TheadjustmentsweremadeonMay5,to1.93inches,andJuly21,to2.40inches.Twoovertopeventsoccurredin2005ontheWestlysimeter,oneonFebruary28andanotheronAugust8.Neithereventwasadjusted.TheabnormalitiesonMay5,andJuly21,werepresent,however,andvaluesof1.21and2.39incheswereinsertedforthesetimes.

verification of turfgrass evapotranspiration

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