Soil scientists have spent many years studying the pattern of soil properties in fields and the processes responsible for these patterns. In this section I ll concentrate on the types of soil variation which occur in the most typical of Saskatchewan landscapes a gently rolling surface. Different soils in a field occur because of the action of soil-forming processes through time. In Saskatchewan soil formation in most of our landscapes began about 14,000 to 10,000 years ago, after the great ice sheets retreated to the north. Most of the soil forming processes which have influenced the landscapes since that time are controlled by the amount of water present at any point in the landscape.
Water is shed from knolls or upper slope positions and drier conditions occur.
These dry conditions limit the amount of organic production that occurs in both natural conditions and in agricultural fields. The result is a soil that typically has lime close to the surface and a thin layer of topsoil. Erosion of soil by wind, water, and tillage since the breaking of the land has removed topsoil from the knolls, and in many cases has mixed the grayish lime layer in with the remaining topsoil. This gives knolls the grayish appearance that we see in many Saskatchewan landscapes. Soils with very thin topsoil layers, or where the lime has been mixed in, are called Regosolic soils.