Weeds aren’t always a farmer’s enemy.
Sometimes they’re an ally. Grant Rigby says weeds helped him tackle soil salinity on his farm near Killarney and led him into organic agriculture.
“The fundamental reason I dropped herbicide spraying was to allow plants to live on those areas of the farm where the crops I planted were not well adapted, like low areas around sloughs,” Rigby said on the sidelines of the Canadian Organic Science Conference at the University of Manitoba Feb. 22.
“Those weeds that grew in that saline area are indeed what saved those patches of ground because I had no technology from humans to achieve that objective.”
By 2004, Rigby’s farm, in the family since 1882, was certified organic.
The telltale signs of salinity — lifeless white patches of salt — are gone.
“All these areas have been recovered,” Rigby said. “I can grow heavy crops of alfalfa in these areas, whereas before alfalfa wouldn’t even get established.”
Rigby periodically breaks up the alfalfa to seed annual crops, but never without another crop such as red clover. Bare soil promotes salinity. Evaporation draws water to the surface leaving salt behind. Plants, when present, draw water up leaving the salts below. Rigby, who has a bachelor’s degree in agriculture and a master’s in food science from the University of Manitoba, described himself as a “high-intensity conventional farmer” in the 1980s and 1990s. He suspects conventional farmers might be earning more than organic farmers now thanks to the recent hike in crop prices, but has no regrets.
The alternative is to sacrifice at least 10 per cent of his farm to salinity, he said.
“The cost of that far exceeds the profit differential in the last three years,” Rigby said. “We’re farming this for the next 1,000 years. It’s not who gets the best house at the end of our lifespan, it’s whether that land produces anything 1,000 years from now. It’s a different way of measuring success.”
Can organic agriculture feed the world?
“Well, we can’t feed the world by losing the landscape to salinity,” he replied.
“I think salinity is a lot worse than people perceive it to be.”
While Rigby is convinced many of the tenets of organic agriculture, including the destructiveness of monoculture are valid, he says some organic and conventional farmers are locked into their respective “religions.”
On the organic side some don’t believe humans can do anything right, while among conventional farmers some pretend pesticides aren’t harmful.
“I was poisoned, my father was poisoned just from accidental exposure,” Rigby said, adding that in his case he should’ve known better.
“It just didn’t get through to me that a poison is a poison and it can do some damage.”
Consumers needn’t worry much about pesticide residues on Canadian-produced food, according to Rigby. Just the same though he hopes people will buy at least some Canadian-grown organic food to support the industry so it can continue to innovate.
Much of what organic farmers and researchers have learned is useful to conventional farmers too, he said.