The Brown Soil Zone
Brown soils and the associated characteristic short-grass vegetation have developed under the most arid climatic conditions in Canada. They are found in the southwestern part of Saskatchewan, the southeastern part of Alberta and in some of the valleys of the southern interior of British Columbia. In general, Brown soils have the shallowest profiles of the grassland soils. The brown top soil may be quite light in colour and it grades into a whitish calcareous horizon at a depth of one to two feet. Other salts may be present as well.
The Dark Brown Soil Zone
The Dark Brown soils are found in a wide crescent extending through the three Prairie Provinces and also in the intermountain areas of British Columbia. The top soil is dark brown in colour and somewhat deeper than that of the Brown soil while the lime accumulation lies at a greater depth and is less concentrated. These are the fertile soils of the "Wheat Belt".
The Black Soil Zone
The Black soils are found under a prairie vegetation of tall grasses and flowering plants interspersed here and there by small groves of aspen and other trees, often termed a "Park" landscape. The surface soil is deep, granular and black with a high content of organic matter. The whole profile is usually deeper than in the other grassland soils although there are marginal areas of "shallow black" soils.
The Grey Wooded Soils
Grey Wooded soils are found in a very large area of the Prairie Provinces and the interior of British Columbia. They have developed in a cooler and slightly more moist climate than that of the grasslands. In keeping with the forest vegetation these soils have grey-leached A horizons but the subsoil contains a zone of lime accumulation similar to that of the grasslands. This is apparently an adjustment in response to the influences of a climate which is alternately wet and dry. The natural fertility of these soils is lower than that of the dark coloured grassland soils. A mixed type of agriculture is therefore necessary. Because of surface conifiguration and the occurrence of swamps and bogs, only a small part of this area is potentially arable.