Soil drainage groups assigned on the basis of soil survey information were evaluated against measured saturated hydraulic conductivity (Ksat) data for nine soils in Ontario. The drainage groups used in the drainage guide for Ontario, are based mainly on assumed relationships between soil texture and the capacity of the soil to transmit water.Measured Ksat values were incompatible with the drainage groups assigned to at least four of the nine soils. For the soils tested, there was very little relationship between texture and Ksat. Structure, including porosity, had a major influence on Ksat, and near-surface structure is influenced greatly by land use. Thus, general interpretations of the drainage characteristics of soil series have serious limitations. The usefulness of soil survey information for interpretation of soil drainage could be increased by improved description of soil morphology and by reliable estimates of Ksat during mapping. Such estimates can be based on morphology if they are regularly recalibrated by measurement. Key words: Hydraulic conductivity, tile drainage, texture, soil morphology
The role of land-use history in major invasions by woody plant species in the northeastern North American landscape