Other soil parent materials found in Saskatchewan

In our previous blog we examined soils developed on glacial till and glacio-lacustrine parent materials. These materials are the foundation of the majority of agricultural soils in this province. Let's briefly look at two other parent materials that represent much smaller areas of the province and produce soils that have limited or no agricultural capability. These parent materials are called Fluvial and Aeolian materials. Fluvial refers to relatively coarse parent material deposited by fast moving water. This water was mostly produced during the melt phase of the last glacial period.  Aeolian materials, in contrast, are wind blown sediments mostly deposited by the prevailing winds at the end of the last glacial period. Aeolian materials, if coarse, are called Dune Sand, whereas, finer silty textured materials are called Loess. When the great ice sheets had melted and retreated there was a period where the exposed parent material was not vegetated and very susceptible to wind erosion.

Fluvial Parent Material

  

Soils developed on fluvial parent materials generally have a very limited agricultural potential.  The precise nature of these materials is determined by the speed of water flow during deposition. In general, the more swiftly that water flows, the coarser the resultant material. Figures 1 and 2 are examples of comparatively fine fluvial material which has some agricultural potential. Figures 3 and 4 provide examples of coarser materials with virtually no potential for crop production.

Figure 1. Field developed on comparatively fine fluvial parent material

Figure 2. Close up of Figure 1, courtesy T. Yates

Figure 3. Fluvial soil profile exposed, courtesy of K. Van Rees

Figure 4. Extreme example of fluvial parent material, courtesy of D. Anderson

                                            Aeolian parent material

Figure 5. Aeolian parent material, Great Sand Hills of SW Saskatchewan

In Saskatchewan, the only significant areas of Aeolian (wind blown) parent materials are found in the Great Sand Hills and the sand dunes of Lake Athabasca. This dune sand material has extremely limited agricultural potential even as pasture. Finer Aeolian material (silt sized soil material) can also be transported by wind. This material is call Loess.  There is very limited area of loess type soils in Saskatchewan however loess is an important parent material for agricultural soils of USA and China.  It is difficult to recognize soils developed on loess parent material because the deposit is generally thin and follows the undying topography.  A microscopic examination of a soil sample is really needed to confirm loess. In Saskatchewan, small areas of loess parent material are located adjacent to coarser sand dune deposits. Hence some loess type soils are found on the eastern side (downwind) of the Great Sand Hills. When these silty-textured soils experience beneficial climate they are capable of good crop production.