| A simple method for the installation of groundwater lysimeters in peat soils
was developed which reduces both time and financial effort significantly. The method was
applied on several sites in the Rhinluch, a fen peat land 60 km northwest of Berlin,
Germany. Over a two-year period, upward capillary flow and evapotranspiration rates under
grassland with different groundwater levels were measured. The installation of tensiometers
and TDR probes additionally allowed the in situ determination of the soil hydraulic
properties (water retention and unsaturated hydraulic conductivity). The results of the
measurements of the unsaturated hydraulic conductivity demonstrate that more than one
single method has to be applied if the whole range of the conductivity function from
saturation to highly unsaturated is to be covered. Measuring the unsaturated conductivity
can be done only in the lab for an adequately wide range of soil moisture conditions.
Keywords: peat soils, soil hydraulic properties, evapotranspiration, capillary flow, root
distribution, unsaturated zone |