Temporal Effects of Subsoiling on the Soil Hydraulic Conductivity and Water Retention of Reconstructed Soils.

Anthropogenic activities, such as industrial development and subsequent landscape reconstruction, cause degradation to soil quality by inducing a high degree of soil compaction. Compaction negatively affects soil aggregates and the pore size distribution which increases the bulk density and alters water storage. Poor vegetative growth has been reported on many reconstructed landscapes as a result of compaction. To alleviate compaction, subsoil ripping has been employed to increase the pore volume and size distribution. The main objective of this study was to assess the medium term (~ 4 yrs) effects of subsoil ripping to a depth of 60 cm at the Genesee Prairie Mine, Alberta, Canada. Soil structure and the pore size distribution, as well as the moisture retention curve (MRC) for ripped and non-ripped were quantified to determine residual effects of the ripping treatment four years after its application. Results showed small differences between treatments. Observable differences were noted in the 15-20 cm depth on the shape of the MRC indicating the development of some discrete pore classes (3-100 ?m diameter). Saturated volumetric water content was increased by ripping in the 5-10 and 15-20 cm depths by 1 % and 4 %, respectively. Evidence of natural attenuation by biological and physical processes was found in non-ripped soils in the surface layers (5-10 cm). Ripping appears to have a positive influence on soil structural development in reconstructed soils.