Nutrient losses from agriculture: Effects on Canadian surface and ground waters

In 1996, Canada had a nutrient surplus of 4.3 kg ha-1 nitrogen (N) and 0.8 kg ha-1 phosphorus (P) for all agricultural land. Although this N surplus is low compared to many European countries, nutrient losses from agricultural land have contributed to environmental problems in Canada: accelerated eutrophication of certain aquatic ecosystems; fish kills; a decline in amphibian numbers; toxic algal blooms; and an increase in the extent to which the drinking water guideline for nitrate has been exceeded in groundwaters. To minimize nutrient release from agricultural activities in Canada, most provinces have adopted or are revising nutrient management strategies for managing the production, storage and utilization of agricultural nutrients.