Measurement of plant xylem water pressure using the high-capacity tensiometer and implications for the modelling of soil–atmosphere interaction

The response of shallow geotechnical structures is affected by interaction with the atmosphere. Since ground surface very often vegetated, plant transpiration plays a major role in such an interaction. Transpiration applications generally modelled way reduction function (e.g. Feddes function). However, its parameters are borrowed from agricultural literature, where focus on crop species and loosely compacted organic soils. For non-crop denser soils typically encountered applications, monitoring flow taking place soil through xylem up to leaves can potentially be exploited characterise function. main challenge measurement water pressure xylem. Techniques currently used include chamber thermocouple psychrometer. destructive thus not suitable for continuous and/or relatively small number available (as occurs laboratory experiments). psychrometer accurate at low tension, presence solutes significantly sensitive temperature. This paper explores novel application high-capacity tensiometer (HCT), initially developed pore-water HCT was installed stem or branch different trees validated against measurements over range down ?1300 kPa. In addition, investigate soil–plant continuum. Results show that viable convenient instrument use provide field-based data modelling transpiration. Installing HCTs stems branches quite straightforward this will help achieve step change testing effect regime vadose zone.