by Hans Peterson, Saskatchewan Research Council, Saskatoon, SK
Most agricultural practices will have some effect on either surface or ground water quality. These effects are generally caused by soil or water movement from agricultural land into ground or surface water systems. The soil and water carry nutrients, pesticides, bacteria, oxygen consuming substances (phosphorus, nitrogen, etc.), and a host of other pollutants. These substances can create direct and/or indirect effects on the use of the water.
A substance such as phosphorus is of no concern for human consumption. However, phosphorus in the dugout will be used by photosynthetic aquatic organisms such as vascular plants and blue-green algae. These organisms can, in turn, cause both direct and indirect effects on the usability of the water for drinking. It is therefore essential to limit substances that degrade the water either directly or indirectly.
To protect surface and ground water from pollution by agriculture, various agencies, especially in the U.S., have developed a host of both mandatory and voluntary best management practices for agriculture. A best management practice is defined as:
measure or practice that when installed or performed will prevent, reduce or correct water pollution." |
Minnesota Pollution Control Agency identifies 26 Best Management Practices for Minnesota. These include nutrient management, integrated pest management, proper pesticide use, irrigation water management, conservation tillage, contour farming, strip cropping, filter strip, field border, cover crop, crop rotation, field windbreak, pasture management, agricultural waste management system, runoff management system, water and sediment control basin, livestock exclusion (fencing), grassed waterway, stream bank protection, wetland development, sealing abandoned wells, and on site sewage disposal system.
The challenge now is to identify best management practices for the Canadian prairie and then follow up by implementation. This is especially important for prairie farmers because of their reliance on water supplies that are intimately linked with the catchment area management (dugouts and shallow aquifers).