The Battle River Soil Reconstruction Project (BRSRP) was established in 1979 to determine the most effective methods of reclaiming lands disturbed by surface mining of coal in the Battle River Coal Fields. The project is located 150 km southeast of Edmonton in a region dominated by Dark Brown Chernozemic and
Solonetzic soils used for agriculture. Subsurface till materials are moderately saline and sodic but deeper mine spoils consist of unconsolidated bedrock that is weakly saline but highly sodic.
The objective of the Subsoil Depth Experiment is to determine the optimum thickness of replacement subsoil over sodic minespoil. The thickness of subsoil replaced under 15 cm of topsoil ranged from O cm (Treatment 1) to 335 cm (Treatment 6 ).
Results from the Subsoil Depth Experiment indicate that forage, but not cereal, yields increase with increasing subsoil thickness. Data are presented that indicate these responses are primarily related to soil moisture regime rather than to soil chemistry. Further, data are presented to suggest that the different crops, cereals versus forage, have different and very important effects on soil chemistry and this is related to their influence on soil water status.
The combination of yield, soil moisture and soil salinity monitoring over a period of years provides extremely important insights into soil forming processes. This understanding is essential to establishing the sustainability of soil quality after mining and has very important implications to agricultural use of
undisturbed lands.