Via: Globe-NET

29 May 2008 – Agricultural run-offs containing fertilizers, animal wastes and pesticides are infecting rivers and water courses with blue-green algal blooms and toxic chemicals. While the problem is particularly evident in developing countries – Canada, Australia and the United States contain some of the world’s most polluted rivers, and poor agricultural practices are the root cause.

Almost one-fifth of the world’s population lacks consistent access to clean water says the United Nations Environment Program, and the problem is being made worse by the improper farming practices – particularly in developing countries where excessive use of fertilizers are needed to feed rapidly expanding populations.

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Canada has a large number of river systems that are highly polluted in part due to agriculture. On the West coast, pollution in both Alberta and BC is affecting Chinook salmon populations, a commercial species. In Eastern Canada Quebec is home to 13 of the nation’s most polluted rivers each of which run through the heart of the province’s agricultural region.

According to Monique Boily, a biology professor and environmental toxicologist at the Université du Québec à Montréal, long-term pollution has made the water unfit for consumption.

“We are talking about an extremely stressed environment … in the case of some of the tributaries, we use the term ‘river’ out of habit or convenience, in some cases it’s more like an open sewer,” said Boily of the Yamaska watershed, the most polluted river system in Canada.

What are the solutions?

Many agricultural experts are suggesting new farming techniques to help limit the amount of agricultural run-off entering river systems, such as the ‘no-till’ technique. According to research conducted by the Thomas Jefferson Institute, ‘no-till’ farming, a process that eliminates the churning of soil, reduces the movement of silt into watersheds by an estimated 95%. Because no-till doesn’t disturb the soil surface, phosphorous and nitrogen fertilizers, which reside within the top six inches of the soil, are not washed into streams and rivers.   Read the rest of the article