The amount of aerosols produced by Canadian agriculture has not been measured routinely but is probably small. The most common aerosol from Canadian farms is probably dust from soil erosion. When soil is dry, loose, and without plant cover, the wind can pick up surface particles and carry them great distances. The problem was most severe in the southern prairies during the dirty thirties, when as much as several centimetres were lost from some fields, obscuring the sky and depositing dust everywhere. Although conservation measures now prevent such large-scale dust storms, occasional erosion episodes still occur locally.
Erosion occurs in two steps.
These two processes account for most erosion. Eventually, the suspended particles settle out in calm winds or are washed out in rain. After the bad experience of the 1930s, researchers developed many erosion control measures. Although severe and widespread erosion has been largely halted, some dust from farmland still enters the air through localized erosion events or during tillage and other farm operations. The dust emitted from soils is not just inert mineral particles.