Farmers need to step up their efforts to reduce the volume
of phosphorous eroding into streams, rivers and the Great Lakes, says Ontario
Environment Commissioner Gord Miller.
He praises farmers for making good progress on phosphorous
reduction during the 1970s and 1980s, but says now more needs to be done
because algae blooms are once again marring the Great Lakes and starving fish
of oxygen.
“If we have more biologically active soil, which
means we adopt no-till systems, and we work with them for a longer period of
time we increase the biological activity,” Miller writes in his annual report.
“The net result is reduced reliance on fertilizer
to provide phosphorus.
“But farmers need the freedom to work out their
own management systems that suit their operations in conjunction with continued
access to good scientific advice, he says.
“We need that liberty in the equation.
Self-directed ownership works, you just have to let it work.”
Miller says the phosphorus strategy would be
similar to the province’s long-standing waste management strategy that promotes
three Rs – reduce, reuse, recycle.
Ontario’s Nutrient Management program is aimed at
limiting the amount of fertilizers, including phosphorous, that are applied to
what’s needed to grow the crop in that field.
Ironically, one of the innovations that could
reduce phosphorous being applied to land is the genetically-modified Enviropig
developed at the University of Guelph, but shelved because obtaining government
approvals has been too costly.
Dr. Peter Forsberg genetically modified pigs so
they produce more phytase in their saliva and that, in turn, improves the pig’s
ability to extract the phosphorous it needs for growth.
By improving the efficiency of phosphorous extraction,
less phosphorous needs to be added to feed rations and less ends up in hog
manure.
Phosphorous is the limiting factor for manure
applications on hog farmers trying to stay within Nutrient Management Plan
volumes.
Reducing tillage has also reduced the amount of
soil that washes into streams, rivers and the Great Lakes. Phosphorous clings
tightly to soil particles, but is released in water.
Little has been said about the increasing volume
of phosphorous that is sequestered in fields where tillage and erosion has been
reduced and whether or when that buildup of phosphorous will be released to
waterways.
On the other hand, municipal sewage treatment
systems remain a huge source of phosphorous draining into the Great Lakes. In
Waterloo, for example, an equipment failure earlier this month resulted in more
than 850,000 litres of untreated sewage spilling into the Grand River.
