Soil degradation has slowed, but it continues at a significant rate and we should guard against becoming complacent about it, attendees heard at the recent Summit on Canadian Soil Health in Guelph.
“There’s a steady decline in interest in soil conservation. I see recently a strong and pervasive belief that we know everything we need to know about soil degradation,” said Dr. David Lobb, of the University of Manitoba, including a “sense of fatigue” about the topic when talking to government and policy people, he said.
Lobb recently completed a study that reported about $3.1 billion worth of crop production capacity is lost due to soil erosion.
He said he is worried that the long-term focus on soil health is being lost.
“It’s not just the mouldboard plow. If we don’t talk about soil movement, we are not going to solve the problem,” he said, pointing at chisel plows and hoe drills used in Western Canada as significant soil movers.
“Vertical tillage: it makes me explode when people call it conservation tillage,” he said.
The end of summerfallow and popularity of no-till in Western Canada has brought major reductions in soil loss caused by wind. In Eastern Canada, Lobb said issues surrounding the use of tillage continue.
No-till farming has declined in Ontario mainly because it is difficult to consistently and easily obtain similar yields from no-till fields than those that have some tillage. That creates more chances for soil erosion.
Ken Laing, an organic farmer from near St. Thomas, Ont., de-scribed what he called the “new soil health paradigm” as using farming practices that leave no bare soils, making sure soil is filled in with cover crops, and reducing or eliminating soil disturbance through tillage. He also said livestock integration is important.
Laing has planted cover crops for decades, but he admitted that organic farming has problems with parts of the new soil health paradigm.
“A major challenge for organic farmers in the new paradigm is reducing tillage,” said Laing.
Organic farmers have to use tillage to control weeds, integrate manure and to kill a previous year’s crop or cover crop. Weed control alone often means numerous tillage passes in a growing season.
Laing is working with different types of organic no-till and planting into growing crops, with variable results from year to year.
Bob Sandford, a professor at the international think-tank United Nations University, said he’s en-couraged by what he saw on soil summit tours in Canada, but there must be more focus on earth systems, including soil health.
“We forget that agriculture is the foundation of our civilization. Agriculture saved us once with green revolution, but it needs to save us again from unintended issues of the green revolution.”
The next green revolution needs to integrate climate, soil and water security at a global level, at the same time as increasing agriculture productivity, he said.
Lori Phillips, an Agriculture Canada soil microbiologist at the Harrow Research and Development Centre, said the golden age of soil microbiology is now underway with new genetic tools that help us identify a small proportion of the microbes that live in soils and also help us understand their functions.