The understanding and measurement of water and matter fluxes in soil/plant/atmosphere systems are important for scientists and decision makers and thus pose an urgent challenge in hydrology and soil science. For this purpose, measurement systems are required that are able to quantify complex processes, i.e. interactions and fluxes between different compartments, with high accuracy and high temporal resolution. Several techniques are available to determine these fluxes, but the different techniques measure at different spatial scales and are affected by systematic and random measurement errors of different size. In the last decade, lysimeter technology has made a substantial progress with respect to measurement precision, internal instrumentation, and coupling of lysimeter systems with highly complex, realistic plant chambers (ecotrones). The processing, handling and correction of lysimeter data has improved considerably as well, and has achieved a high level of automation. A state-of-the-art lysimeter contains an undisturbed monolith, is continuously weighed with high accuracy and time resolution, has defined boundary conditions, and avoids any island effect by a perfect embedding into the surrounding environment. Hence, large lysimeters can be used as precision measurement instruments for validation of coupled environmental processes like evaporation, transpiration, night-time transpiration, dewfall, and solute transport. The session invites contributions that address the state-of-the-art lysimeter technology/ecotrone as well as process studies and modelling studies that are based on lysimeter technology.