Bainsville farmer credits soil fungus for win

Thursday, March 1, 2012

by SUSAN MANN

Shawn McRae is convinced fostering conditions in his sandy-loam soil to encourage a soil fungus, called mycorrhizae, is helping him grow better more nutritious crops while at the same time saving money on fertilizer and fuel.

McRae, a Bainsville-area farmer growing corn, dry beans, soybeans, oats and barley on 800 acres, says doing too much tillage eliminates crop residues, which is the fodder for fungi and large earthworms.

“Those certain species that depend on that surface residue will be eliminated from the soil environment and they perform very important functions,” says McRae, who received the BASF Innovative Farmer of the Year Award on Feb. 28 at the Innovative Farmers Association of Ontario annual convention in London. McRae won a plaque and a $1,000 prize.

Certain species of the fungi invade crop roots. The fungus brings in nutrients that are hard for the plant’s roots to find on its own, such as zinc and phosphorus. “The fungus acts like an extension of the crop’s roots,” says McRae, an agronomy graduate from the University of Guelph.

The plant makes sugar in its leaves and sends that down into its own root system for the fungus. It’s a mutually dependent relationship.

“What we’ve found in our farming system is we can reduce our dependency on purchased soluble phosphorus fertilizer because we’ve gained an appreciation for the function of this soil fungus and we’ve changed our practices to nurture the environment for it,” he explains. “That means less tillage.”

McRae notes the fungus has a network structure that persists from year to year similar to a perennial plant. But dragging a tillage tool through the ground smashes the network to pieces. Farmers don’t see that happening from their tractor seat but that’s the implication of using tillage.

Having the soil fungus present makes for a better plant. But the “ultimate implications would be for better human nutrition,” he says. Growing crops that are accessing these nutrients more naturally means they may be less deficient in some of the micronutrients, such as copper and zinc.

Sponsored by BASF Canada, the Innovative Farmer of the Year award is presented annually to the Ontario farmer who has used innovative farming practices and demonstrated leadership within their community and the sector.

McRae considers it a huge honour to have won the award. The Innovative Farmers Association is one of the best farm organizations in Canada and the farmers involved in it think creatively and are on the cutting-edge of innovation, he says. “To have them consider me to be an important innovator means a lot.” BF