SVERIGES LANTBRUKSUNIVERSITET - Epsilon Open Archive - SLU
SVERIGES LANTBRUKSUNIVERSITET - Epsilon Open Archive - SLU
SVERIGES LANTBRUKSUNIVERSITET - Epsilon Open Archive - SLU
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-40.0<br />
.-,.-30.0<br />
:. - 20.0<br />
:E - 10.0<br />
-ca .- .... c<br />
el) ....<br />
o<br />
o.<br />
...<br />
el)<br />
....<br />
ca<br />
==<br />
-2.5<br />
Fig.4<br />
A<br />
1<br />
B c D E<br />
I I<br />
Soil Root Stem Leaf Atmosphere<br />
Idealized water potential gradients through the SP AC. Curves 1<br />
and 2 represent plant water removal from relatively wet soil at<br />
low and high transpiration rates, respectively; curves 3 and 4<br />
represent plant water removal at low and high transpiration<br />
rates, respectively, af ter soil water potential has been reduced to<br />
-0.6 MPa. (Af ter Hillel, 1980).<br />
where qr' VJrsm' VJM' k s ' rroot and rcyl are the rate of root water uptake, the<br />
soil matric potential at the root sunace, the bulk soil matric potential, the<br />
hydraulic conductivity of the soil, the radius of the root, and the radius of<br />
the cylinder of soil through which water is moving, respectively. This model<br />
(eq. 8) describes radial transport of water to the root surface from the<br />
cylinder of soil effectively occupied by a root.<br />
4<br />
2<br />
3<br />
1<br />
53