Soil physical characteristics of peat soils

Abstract

Drainage and intensive use of fens lead to alterations in the physical characteristics of peat soils. This was demonstrated using parameters of water balance (available water capacity) and the evaluated unsaturated hydraulic conductivity. Deriving the distribution of the pore size from the water retention curve was flawed because of shrinkage due to drainage, especially at high soil water potentials. These errors became greater as the peat was less influenced by soil‐genetic processes. The water retention curves (desorption) evaluated in the field and the laboratory satisfactorily corresponded. However, the wetting‐ and drainage‐curves obtained in the field differed up to 30 vol.‐% water content at same soil water potentials. These differences were largely due to a wetting inhibition.

An easily installable groundwater lysimeter to determine waterbalance components and hydraulic properties of peat soils

“…In the course of establishing a water retention curve, the peat shrinkage after each pressure level was quantified by measurement with callipers. Schwärzel et al, 2002 showed that the shrinkage can be negligible under field conditions. The determination of the unsaturated conductivity was carried out in three replications (237 and 550 cm 3 cores) using an evaporation method (Plagge et al, 1990).…”

Hydrological properties of duff

“…Measured porosity values range from 0.81 cm 3 cm À3 to 0.92 cm 3 cm À3 and are similar to values found in previous studies on duff [Fosberg, 1977;Ferguson et al, 2002;Miyanishi and Johnson, 2002;Redding et al, 2005] and peat [Heiskanen, 1999;Weiss et al, 1998;Naasz et al, 2005;Wotton et al, 2005;Schwärzel et al, 2002Schwärzel et al, , 2006. The differences within each category exhibit a pattern similar to that seen with conductivity.…”

Does <i>Juncus effusus</i> enhance methane emissions from grazed pastures on peat?

“…In comparison, the peat at Fussingø and Torsager sites were categorized as H8 and H6, respectively. Schwärzel et al (2002) concluded that, due to shrinkage and mineralization processes, degraded peat soils will maintain a high volumetric water content during periods of drying, and a decline in the proportion of macropores > 100 µm, which could have contributed to their ability to generate CH 4 . The CH 4 accumulation we observed in the unsaturated zone during spring and early summer (Fig.…”