60
/\ViPHWHU ZHiJKinJ ZDV SHUIRUPHd dDiO\
EHIRUH iUUiJDWiRn.
Results and Discussion
,n ERWK RI WKH VWXdiHV WKH VXEVWUDWH
PRiVWXUH FRnWHnW diVSOD\Hd D UHdXFWiRn
WKDW ZDV VHHn WR EH PRUH SUHFiSiWRXV DW
the initiation of the irrigation treatments
(See Figures Two and Three) .
Differences between the two irrigation
UHJiPHV 5 Dnd 65 E7R ZHUH
PRUH SURnRXnFHd in FRPSDUiVRn
ZiWK WKH VXEVWUDWH dHSWK WUHDWPHnW.
In both study years the moisture
RI WKH VKDOORZ VXEVWUDWH dHSWK ZDV
inFUHDVHd FRPSDUHd ZiWK WKH dHHSHU
VXEVWUDWHV ZKiFK iV in FRnWUDVW
WR SUHYiRXV UHVHDUFK Rn JURZinJ
WXUIJUDVV Rn JUHHn URRI DOWKRXJK WKH\
did VXEVWDnWiDWH WKH WKHRU\ WKDW dHHSHU
SURÀOHV UHWDinHd KiJKHU PRiVWXUH
FRnWHnW DOWKRXJK WKHVH ÀndinJV ZHUH
UHDFKHd ZKHUH ZDWHU DSSOiFDWiRnV
ZHUH VSDFHd WKUHH dD\V DSDUW.
:KHUH iUUiJDWiRn VFKHdXOinJ WRRN SODFH Rn D dDiO\ EDViV iW
was found that the same amount of water was distributed
PRUH UDSidO\ Dnd dHFUHDVHd PRUH DEUXSWO\ DW WKH ORZ
iUUiJDWiRn UHJiPH 65 E7R Dnd WKH VKDOORZ VXEVWUDWH
SURÀOHV 7.5 FP in ERWK VWXd\ \HDUV.
Conclusions
7KH REVHUYHd diIIHUHnFHV EHWZHHn WUHDWPHnWV inÁXHnFHd
FXPXODWiYH EYR dXUinJ WKH ÀUVW VWXd\ \HDU ZKHn
WHPSHUDWXUHV Dnd ZiWK iW HYDSRUDWiRn ZDV PXFK KiJKHU
ZiWK iUUiJDWiRn DW 5 RI WKH OHYHO RI E7R H[KiEiWinJ WKH
HIIHFWV RI KiJKHU HYDSRWUDnVSiUDWiRn FRPSDUHd ZiWK 65
E7R RnO\ DIWHU 20 dD\V RI ZDWHU VWUHVV iPSRViWiRn KDd
SDVVHd ZKiOH WKH diIIHUHnFHV EHWZHHn WKH WZR VXEVWUDWH
dHSWKV ZHUH IRXnd WR EH inViJniÀFDnW.
'XUinJ ZDWHU VWUHVV SHUiRdV WXUIJUDVV FDn JURZ Dnd HYHn
WKUiYH Rn H[WHnViYH JUHHn URRI V\VWHPV SURYidHd iUUiJDWiRn
iV nR OHVV WKDn 5 RI E7R.
,n DddiWiRn iW ZDV REVHUYHd WKDW VXEVWUDWH dHSWK FDn
EH FRPIRUWDEO\ UHdXFHd IURP 15 FP WR 7.5 FP ZiWKRXW
ViJniÀFDnWO\ VWUHVVinJ WKH WXUIJUDVV SODnWV EDVHd Rn
ÀndinJV WKDW HYDSRWUDnVSiUDWiRn dHSHndV Rn WKH DSSOiHd
iUUiJDWiRn UHJiPH Dnd nRW Rn WKH VXEVWUDWH dHSWK. ■
Figure Two:Volumetric water content as affected by irrigation regime (85 or 65% ET)
during the first study year
Figure Three: Volumetric water content as affected by substrate depth (7.5 or 15.0 cm)
during the first study year
During water
stress periods
turfgrass can
grow and
even thrive
on extensive
green roof
systems
provided
irrigation is
no less than
85% of ET