résistance au transfert d'eau liquide

CONT: [...] la résistance au transfert d'eau liquide dans le sol ou le continuum sol-plante est le quotient de la différence de potentiel hydrique total [delta psi]T entre deux niveaux par le flux liquide [phi] : R = [delta psi]T/[phi].
OBS: résistance : Paramètre qui figure dans les équations de transfert de gaz, de liquide ou de chaleur exprimant le flux en fonction d'une différence de concentration, de potentiel hydrique ou de température.

CONT: The driving force for root uptake is the water potential difference between soil and plant. Water is transported from high potential to low. There are two principally different resistances to water transfer from the soil to the exchangeable pool in the plant. In the soil, the resistance depends on soil characteristics and soil water potential, while in the plant, biological factors regulate the resistance. The first resistance is called the soil-root resistance (rr) and the second is called the plant resistance (rp) and they are coupled in series, i.e. a water molecule has to path both resistances.
CONT: Access to water can be more difficult because the soil close to the roots tend to dry more quickly. The resistance to water transfer towards the roots gets stronger. But water uptake is essentially limited by the heterogeneous distribution of the roots in the soil.