The soils of the prairies developed under grassland vegetation, which supported substantial populations of numerous animal species. At the same time, sloughs and potholes dotted the landscape, providing habitat for birds and other wildlife. Trees in river valleys also provided sanctuary. The vegetation of the region varied from short grasses in the drier sections, to tall grasses in areas of increased rainfall, to reeds and sedges in low-lying areas.Agricultural development has irrevocably altered the natural landscape of prairie Canada, affecting both physical attributes and biological resources. As agriculture became more intensive and farm equipment increased in size, wetlands were drained, trees removed, and grasslands cultivated.
As a result, habitat for many plant and animal species has been lost to a grains and forage monoculture. Remaining areas of unaltered wildlife habitat have become progressively more fragmented, more isolated, and often too small to sustain viable populations of once abundant species.
Grazing by cattle and other domestic animals reduces plant cover and the supply of food and shelter for meadow and grassland species of mammals, birds and invertebrates. On the other hand, some forms of wildlife thrive under conditions arising from agriculture. Farm shelterbelts and abandoned farmsteads provide cover for numerous species of birds. Other species have benefited from increased feeding opportunities provided by agricultural crops.
While the area devoted to farming in the Prairie Provinces has not increased over the last two decades, land use continues to evolve. Since 1981, there has been a dramatic decrease in the practice of summer fallowing, from 20 percent to 7 percent of the area in farms in Alberta and Saskatchewan. This decrease in summer fallow is almost entirely taken up by an increase in area under crops. Cropped areas now cover 52 percent of the farm area of the two provinces. Significant changes in cropping practices have also occurred during this same period, with an ever-increasing number of farmers adopting zero or minimum till. In general, current tillage practices improve soil moisture for crop growth, but lead to less runoff.
Another significant trend is that farmers increasingly rent the land they farm rather than owning it. Stewardship of agricultural land, therefore, becomes a joint responsibility of the owner and renter.
The environmental sustainability of farmed areas of the Saskatchewan River basin cannot be considered without first considering the factors that affect environmental, social and economic aspects of agricultural production. These factors include protecting quality and productivity of farmed soils; reducing soil erosion and salinity; conserving and restoring soil organic matter; protecting quality of surface and groundwater; preserving and restoring riparian zones; and maintaining or improving the quality of rangelands. Careful attention to these factors will inevitably lead to a better match of land use to land capability. Enhancing the sustainability of agriculture production can, with care, improve environmental performance.