StudentNotesLecture12–GrapevineWaterRelationsandIrrigationSlid
e1GrapevineWaterRelationsandIrrigationGreenplanttissue90%
ormorewaterWateressentialforbiochemicalandbiophysicalpro
cessesSlide2Deeprootsystemscantoleratemilddroughts,shallo
wrootsystemslesssoIrrigationis‘insurance’againstdroughtp
eriodsAddstofixedcostsofestablishmentPoorlymanagedirrigati
oncandecreasefruitqualitySlide3Vineyardhydrologiccycle-F
igure9.1Gain–rainfallandirrigationLoss–runoff,infiltratio
nandpercolation,evaporation,usebyvinesStorage–soil(deter
minedbytextureanddepth)Slide4PAW–plantavailablewaterPAW
moreinfinetexture(silt,clay)soilsandlessincoarsetextur
e(sand)soilPAWmoreindeepsoilsandlessinshallowsoils0.1
to0.2inchperinchofsoil(1to2inchesperfootofsoil)Slid
e5Otherconsiderations:YoungvineshaveshallowrootsystemsRoot
stockshavevaryingrootingdepthWeedsandpermanentgroundcover
scompeteforPAWSlide6Evapotranspiration(ET):Evaporationfrom
soilTranspirationfromleavesFactorsthataltertranspiration:PAW
,airtemperature,wind,humidity,sunlightET-1.3to2inchesp
erweekinmidsummerSlide740to60inchesofannualrainfallin
eastandMidwestUSInfrequentsummerdownpoursdonotalwayssati
sfygrapevineneedsETlossoftenmorethanrainfallgaindurings
ummermonthsSoilareservoirofwaterbetweenraineventsSlide8A
dequatelywateredvinesexert‘turgorpressure’–cellenlargemen
t,increaseintissueandorgansize,shootgrowthDroughtstress
impairsthisSlide9Droughtstresssymptoms–Table9.1Reversible
andirreversibleeffects–page173rightSlide10AridclimatesIrr
igationwatermanagementtobalancegrowthandfruitingTable9.2,
generallydesiredwaterstatusFivestagesofgrapevinegrowthha
vevaryingneedsofPAWSlide11Dripcomparedtooverheadirrigati
on–Table9.3Drip–main,submains,headerormanifold,laterals
,emittersMain,submains,headerormanifoldburiedLateralshung
ontrelliswireorburiedPressurecompensatingemittersusedons
lopinggroundSlide12Dripirrigationrequireshighqualitywater
–watertestingimportantGroundwateracleanersourcethansurfa
cewaterFiltrationneededinsurfacewaterWaterflowmustbedete
rminedSlide13ConsultanirrigationdealerDesignserviceusually
providedforpurchasingsuppliesNeeds–websoilsurveyarea-of-
interest,vineyardlayoutsketch,watersupplyandpumpingdetail
s,powerpolelocationSlide14Dripirrigationcomponents–Figure
9.5Emitters–non-pressurecompensating,pressurecompensating,
externalorinternalinpolyethylenetubingortapeSlide15Pump–
centrifugalforshallowwellorsurfacewater,submersivefordee
pwell,matchwatersourceyieldtopumpoutputPressureandholdi
ngtanks–providecontinuouswatersupplySlide16Main–extends
frompumptosubmains,buriedPVCpipeSubmains–branchedextensi
onsofmain,usedformultiplevineyardblocks,valvesusedtotu
rn-onandoffsubmains,buriedPVCpipeHeaderormanifold–pipe
alongheadendofrowsthatlateralsareattached,buriedPVCpip
eorflexible‘layflat’Slide17Backflowprevention–preventssip
honingofcontaminatedwaterandchemicalsbackintowatersource
Filtration–amountdependsonwatersource(groundversussurfac
e);driprequirescleanwater;filtertypesscreen,disk,andsan
dSlide18Pressureregulation–doneinheaderormanifoldjustbe
forelateralswithemitters,dropswaterpressureto8to10poun
dspersquareinchChemicalandfertilizerinjection–donebefore
thelaterals,backflowpreventionnecessarySlide19Maintenance:S
pring–inspectfordamageandrepair,pressurizeandflush,tie-
uplateralsGrowingseason–checkwaterpressure,inspectlateral
sandemittersforproperoperationWinter–pipesandlateralsch
emicallytreat,flush,anddrainSlide20Schedulingirrigation:Vis
ual,waterbudget,soilmoistureVisual–wettinganddryingpatte
rnsofvineyardsoil,canopyorleaftemperaturebytouchorther
mometerSlide21Waterbudget–keeptrackofevapotranspiration,s
oilwater,rainfall,andirrigationTable9.4–PAWfordifferent
soiltexturesTable9.5–waterbudgetSlide22Evapotranspirationc
alculation–pages178and179Example:ETforagrapevine–0.12i
nchesperdayor0.84inchesperweekDripirrigationefficiency9
0%Dripirrigationmustapply0.93inchesperweekSlide23Soilmoisture–soil‘squeeze’test(Table9.6),tensiometers(Figure9.6),guidelinesforusingtensiometers(Table9.7),gypsumandWatermarkblocks,timedomainreflectometry,capacitanceprobesTopfootortwoofsoilmeasuredSoilshouldberepresentativeofvineyard1 |
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