Phosphorus is a plant nutrient with an essential role in helping farmers keep up with the world’s growing food demand. A recent reassessment of rock phosphate reserves calmed worries that the global resource was running low. However, it remains in the spotlight because the nutrient, from farm fertilizer, livestock manure and municipal sewage, washes into lakes and oceans, creating dead zones depleted of oxygen and aquatic life.
The Western Producer’s Robert Arnason reports on how an apparent phosphorus shortage turned into a comfortable supply and how researchers are finding ways to capture and recycle the nutrient so it does not pollute water.
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Phosphorus is a blessing and a curse. It helps make crops healthy and resilient, but if it runs off into waterways it can promote the excessive growth of algae that eventually die and rob lakes and oceans of oxygen and aquatic life.
Phosphorus run off, from farm fields, livestock manure and municipal sewage, is helping to suck the life out of Lake Winnipeg, the 10th largest freshwater lake in the world.
Manitoba’s hog industry has been fingered as a key culprit.
That’s why Lorne Greiger, research and development, research and development manager for the Prairie Agricultural Machinery Institute in Portage la Prairie, Man., received funding last year to evaluate technologies to remove phosphorus from hog manure.
Certain hog farms in the province, mostly in the southeast, will soon need to treat manure because there isn’t sufficient cropland in the neighbouring area to apply it without exceeding phosphorus loading limits.
The treatment will require capital investment, but Grieger said the good news is Manitoba’s farmers need that phosphorus.
“We’re always bringing phosphorus into the province for crop application,” he said. “We can use all the phosphorus we produce from manure.”
He said the problem is how to efficiently recover phosphorus from manure and distribute it to where it is needed.
Don Mavinic, a University of British Columbia civil engineering professor, has a solution to this quandary.
Mavinic and his UBC colleagues invented a nutrient recovery technology in the 2000s that removes phosphorus from human waste and converts it into a quality fertilizer called Crystal Green.
Ostara of Vancouver licensed Mavinic’s technology in 2005 and operates commercial scale reactors to recover nutrients from sewage treatment plants in Portland, Oregon, and Suffolk, England.
It is also testing demonstration plants at sewage treatment centres in North America and Europe.
Mavinic’s discovery has not gone unnoticed. Last year the Ernest C. Manning Awards Foundation recognized Mavinic with one of Canada’s most prestigious prizes for innovation and a $25,000 cheque.
Governments and sewage treatment plants are lining up to buy his technology, but Mavinic believes livestock waste represents a much larger opportunity to recover phosphorus.
