Abstract
We measured saturated hydraulic conductivities, unsaturated hydraulic conductivities and water retentivities of Bibai peat soils, consisted of highmoor peat (natural moss), transitional peat and lowmoor peat. The transitional moor soils exhibited remarkable anisotropy of permeability. The vertical saturated hydraulic conductivity was utmost about 400 times more than its horizontal saturated hydraulic conductivity probably due to the horizontal sedimentation of plant fiber. This anisotropy was most remarkable in the subsoil of a paddy field under the dressed soil and was less in the undisturbed soils under windbreak. Soil dressings and continuous cultivations may have affected the appearance of the intensive anisotropy. The unsaturated hydraulic conductivities of transitional peat and highmoor peat were quite small and were less than those of sand. This feature caused the necessity of relatively long time for the equilibration of water retention.
