Measurements of soil permeability anisotropy by three techniques

Measurements of vertical and horizontal components of hydraulic conductivity were made by the falling head permeameter, the standard piezometer and the piezometer with packing device on 4 farms in the Saint-Lawrence lowlands of Quebec, Canada. All fields are considered to be between imperfectly and slowly drained.The values obtain by the 2 types of piezometer were calculated with the aid of 3 different equations and were compared.The falling head permeameter technique was found to be not appropriate to study anisotropy in clay and clay loam soils due to its high variability and small volume of soil sampled.Both piezometers were found well suited to make directional hydraulic conductivity measurements. Values of vertical hydraulic conductivity twice greater than values of horizontal hydraulic conductivity were obtained by piezometer measurements in a subsoil of a St-Benoit soil series