It was standing room only in the University of Manitoba’s Carolyn Sifton Lecture Theatre Jan. 21 for a seminar entitled “Conservation agriculture, organic farming and agro-ecology: the three musketeers of a sustainable food system.”
“I try to do this every year because I want to give the graduate students permission to ask tough questions and to think about things differently,” said Martin Entz, a researcher and professor with the plant science department.
Although conservation agriculture, organic farming and agro-ecology were named in the presentation as the “three musketeers” of a sustainable food system, Entz says “agro-ecology” is really an umbrella term for any approaches to food production that bring ecological principles to bear in agro-ecosystems, including conservation farming and organic farming.
Soil health is at the heart of conservation agriculture, which emphasizes soil management practices that minimize disruption to soil structure and biodiversity.
No-till (or zero-till) farming aims to increase the soil’s moisture retention and minimize run-off. According to Entz, no-till farming is a system of “organized complexity” that increases soil microbial levels, and increases the soil formation rate, while reducing soil loss.
“Soil biology is the newest of the soil science disciplines but it’s very important — it has helped farmers and watersheds and made a difference,” Entz said.
He went on to argue that conventional systems of agriculture are herbicide dependent, with Roundup still the world’s most-used chemical input, and this puts too much pressure on the soil. “Glyphosate is implicated in having an influence on soil microbiology and gut microbiology of ruminant animals,” he said. “Can we imagine a no-till system without herbicides?”
Entz and his team have worked in various sites around the world studying mulch-based systems that require no weeding or synthetic herbicides. Cover cropping and crop-livestock integration studies are underway that analyze the effects of such approaches on long-term soil stability.
Entz has spent 25 years studying organic farming. His ongoing study at Glenlea, Man., is Canada’s longest-running organic/conventional cropping comparison study. The Glenlea study has produced a host of research papers comparing the productivity and health of conventional and organic systems. “Glenlea has brought a lot of interesting collaborators together, and we’ve learned to respect the science,” he said.
In his presentation, he identified two reasons for moving to organic farming: it’s a market-driven, accredited production system; and it provides the advantage of avoiding synthetic inputs, GMOs or animal growth hormones.
There are many challenges ahead for organic farming, but Entz sees these as opportunities for creative research. He points to a recent study that looks at the contributions of arbuscular mycorrhizal fungi to wheat production and nutrient uptake in conventional and organic systems. The paper argues, in brief, that conventional systems create environments more conducive to healthy AM symbiosis for wheat than organic systems.
“In the paper, they suggest we reduce the abundance of mycorrhizal species in the soil. But reducing biodiversity should not be our first step — we’re already doing that with glyphosate,” argues Entz. “What are the other ways of doing that?”
Entz sees organic farming as a puzzle the scientific community is trying to put together. “In many cases we’re coming up with solutions to problems that are both more creative, which makes the scientist happy, and also more durable, because they’re based in ecology,” he says. “It’s like designing a farming system using the approach of chess, which is upstream thinking, planning several moves ahead, versus our current agricultural science paradigm, which is reactive, like checkers.”
Entz defined agro-ecology as the science of applying ecological concepts and principles to the design and management of sustainable food systems, and as a “scientific discipline.”
He cited a meta-analysis of agro-ecological innovations in the developing world by Jules Pretty that argues that application of these systems would result in a 79 per cent increase in yields and food supply.
“This kind of thinking goes against current dogma. Canadians and Americans want to sell technology. Agro-ecology is a new discipline and we need to develop the art and social science around it,” he said. “It will allow us to move forward both in conservation agriculture and organic agriculture.”