The pockets of higher risk can be attributed to a combination of phosphorus source-where phosphorus levels in the soil have been increasing as a result of mineral fertilizer use and manure from livestock production-and phosphorus transport to surface water bodies. Note that in the Prairies, risk is considered to be moderate, with pockets of low and very low risk in north and central regions as well as pockets of high and very high risk in southern Saskatchewan and Manitoba as well as in central Alberta. Use the interactive map below to zoom in and explore different regions. There are some areas of increased risk in the Prairies, but these are generally from the very low to low or moderate risk categories. Quebec and Atlantic Canada have shown increases in risk, although these have been ameliorated by the soils with high capacity for holding phosphorus.

Southern Ontario has shown declines in risk, although these declines have been from very high to high risk categories. Phosphorus risk has been stable from 1981 to 2016, although there have been changes in the geographic distribution of risk. This indicator has tracked phosphorus risk associated with Canadian agricultural activities from 1981 to 2016.

The Phosphorus Indicator (official name: Indicator of the Risk of Water Contamination by Phosphorus) evaluates the relative risk of surface water contamination by phosphorus across agricultural areas in Canada.

Phosphorus ag source