TRANSPORT PROCESSES IN THE SOIL-PLANT SYSTEM 



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SORPTION/ 

 DESORPTION 

 CURVE 

 O MODERATE WILT D 



© SEVERE WILT Q 



• VERY SEVERE WILT ■ 



DESORPTION 

 CURVE 



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15 30 45 60 



DIFFUSION PRESSURE DEFICIT (ATM) 



75 



Figure 5. Relative turgidity as a function of DPD, showing hysteresis effects (Slatyer, 



1957). 



tial between the root and the surrounding soil as a function of time, 

 assuming a D/a- \akie of 200, where D is the diffusivity and a is the 

 radius of the root. Curve a in Figure 7 represents the vakies obtained 

 if the flow is assumed to be constant for a 24-hour period. Curve b is for 

 a flux double that for curve a for the first 12 hours, wTth no flow for the 

 last 12 hours. For curve c the total flux for the 24 hours is the same as 



