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By Tanya Brouwers
In response, and with the aim of encouraging further research and influencing policy, Dr. Derek Lynch, Canada Research Chair in Organic Agriculture, at the Nova Scotia Agricultural College has published a paper, “The Environmental Impacts of Organic Agriculture: A Canadian Perspective” that compiles recent North American and Canadian organic agricultural research, especially as it relates to the principles of the Canadian organic standard. Given the recent climate change summit in Copenhagen and the global community’s push to reduce CO2 emissions, the sections of Lynch’s paper that compare the energy use and the greenhouse gas emissions on both organic and conventional farms is of particular interest.
Several organic management practices, especially the tillage required for weed control and the legume rotations utilized for fertility, have been criticized for their energy consumption and the CO2 emissions they release. Lynch, in an effort to substantiate or disprove the mounting criticism, assembled those studies that dealt with the comparative net energy balance of organic management systems in Canada and North America. Of the three energy use studies reviewed in the paper, all of them concluded that energy use in organic farms was lower than that of conventional farms.
Lynch cites a 12 year Manitoba study of two forage and grain crop rotations managed either organically or conventionally. After the data was compiled and compared, including crop yield, crop inputs, fuel usage and machinery, the study concluded that energy use was 50% lower and energy efficiency was higher in the organic versus conventionally managed systems. A similar study out of Washington, comparing organic and conventional apple production, found that the organic system used 9% less energy inputs and was 7% more energy efficient than the conventionally managed orchard. Finally, Lynch presents a study, conducted from 1981 to 2002, that compares the energy inputs for corn and soybeans grown in organic and conventional systems. The study found that fossil energy inputs were, on average, 30% lower for the organic than the conventional systems.
Lynch then proceeds to examine those studies that compare the greenhouse gas emissions on organic and conventional operations. He concedes that while research is relatively scarce and in its infancy, that which is available is “intriguing” and certainly deserving of more investigation.
One notable study, conducted in an orchard system in Washington, found that after 9 years, the soil in the organically managed orchard not only exhibited greater soil organic matter and soil microbial activity, but also fostered a much larger and more efficient denitrification community than in the conventionally managed orchard. These denitrifiers perform a “valuable ecosystem service” by converting excess nitrates into benign N2.
Another significant study out of Atlantic Canada, examines the effect of crop, timing of forage tillage and potato fertility regime (preceding the crop with or without the addition of an inorganic N fertilizer) on N2O emissions. Although the study is still in the early stages, preliminary results indicate that potato and forage crops relying on organic sources of nitrogen (legume or animal manure) emit less N2O than those crops supplemented with inorganic fertilizers.
Derek Lynch, citing a study
by MacRae and others (2007), notes that
if the true costs of food production were to include the costs to the
environment, organic food and agricultural systems would command a
greater presence in both the marketplace and in the Canadian agri-political
arena. Unfortunately, organic agriculture’s attributes have been
largely absent from Canada’s political agenda, despite the fact
that "costs" like climate change will directly and adversely
impact our agricultural industry. Lynch’s paper, which he admits
is by no means exhaustive, is a vital first step in compiling the information
and evidence necessary to convince Canada’s policy makers of
the undeniable environmental and ecological benefits of the Canadian
© 2012, Organic Agriculture Centre of Canada (OACC)