Canada’s Fraser Valley exchanges cows for chickens and fog

29-03-2007 | |

Beef and dairy, which require large amounts of land for feed production, have been largely replaced by intensive poultry and egg production, vegetables and raspberries.

Of course, more chickens, means more chicken litter. Production of poultry manure has doubled since 1991. The chicken litter contains high levels of nitrogen. Nitrogen enters the local ecosystem in chicken feed, trucked in by the tonne. Poultry manure has been used extensively as fertilizer containing nitrates, nitrogen with oxygen. Some plants have an appetite for nitrogen in fertilizers, but the area’s dominant crop, raspberries, require very little.
Ammonia is a second significant by-product of animal manure production and while it doesn’t persist in the soil it does have a visible impact on life in the Fraser Valley . The milky white haze that hangs over the area every spring and summer carries a dangerous cocktail of toxins that irritate the eyes and throat and contribute to asthma, heart and lung disease.
Environment Canada scientists are concerned enough about the potential health impacts of white haze that they are studying ammonia emission rates and examining computer models that forecast how it reacts in the atmosphere to form aerial particles. Their yet-to-be-released study will be used to retool agricultural practices and set goals for emission reductions, according to Peter Schwarzhoff, head of the air quality division of Environment Canada.