CONTINUITY OF WATER TRANSFER IN SOIL-PLANT SYSTEM - THE CASE OF FRUIT-TREES

A thermal method for measuring sap flow in apple-free trunks and roots, combined with a wafer-soil transfer study has been utilized to investigate water transfer in a soil-plant system. It has been shown that: i) heterogeneities of sap flux are present in apple-tree trunk and root systems; ii) these heterogeneities are closely correlated and induced either by the heterogeneity of roof density in moistened homogeneous soil or by the heterogeneity of different soil horizon wetting in moistened heterogeneous soil; and iii) the spatial distribution of daily water-soil loss is in agreement with the spatial distribution of wafer-soil extraction by the different root bundles. It has been concluded that a continuous flow exists between one soil sector, the root bundle present in that soil sector, and the trunk sector corresponding to the root bundle.