The Canadian government says six tonnes a hectare is an acceptable level of soil loss each year. Well, that’s not acceptable to soil health expert Nicole Masters.
“Soil is our greatest export,” said Masters, director of Integrity Soils in New Zealand.
“We took out a lot of our soil resources when agriculture really intensified. You guys have done an amazing job by shifting to zero-till in terms of getting on top of some of those soil losses, but you’re still losing soil.”
In Canada, producers lose about one to two tonnes of topsoil for every tonne of grain produced, said Masters, who spoke at a recent workshop hosted by Foothills Forage and Grazing.
“If you’re producing pretty good tonnage of grain, often you’re losing a lot of topsoil in that process,” she said.
“If we measure success only by yield, we’re telling the wrong story.”
Right now, Canadian farm debt is “skyrocketing,” but net farm income “hasn’t changed a lot.”
“I’m not interested in playing in that kind of field. I want to look at how we can be profitable.”
Nitrogen, for instance, is a major driver of yield, but it’s relatively inefficient, with only five to 25 per cent of applied nitrogen being used by crops.
“It’s one of the most costly inputs for an operation, and so little of it is actually used. As a business plan, it doesn’t make a lot of sense,” said Masters. “We’ve got to look at how we improve the efficiencies of the nutrients that we’re putting in.”
Producers can start “building resilience” by focusing on soil health, she said.
“We start to see a soil that holds onto water and can buffer excess water, while having reductions in pests, weeds, and disease.”
And that starts with soil carbon.
“If we build soil carbon, that’s a big part of holding onto extra water,” said Masters, adding that one per cent soil carbon can hold about 15,000 gallons of water an acre.
“But most of the research that’s been done on carbon has been focusing on the ‘I’m here for a good time, not a long time’ carbon. It’s important, but it’s not what’s driving the deep carbon.
“That’s being driven by mycorrhizae.”
Mycorrhizae — fungi that form a symbiotic relationship with plant roots — can increase the surface area of roots up to 10,000 times, which increases the amount of water and nutrients a plant can gather from the soil.
Plants also use mycorrhizae to send out their carbon and order their ‘food,’ said Masters.
“You can drive in your car and go get some food, but a plant can’t do that,” she said. “The currency in the soil is carbon. Plants pay the microbes with carbon.
“They send out that carbon and in comes your nitrogen, your water, your phosphate, and your zinc. If you’re not getting adequate nutrition in your plants or you’ve got trace element problems, this cycle is not working.”
A quick way to tell if mycorrhizae levels are healthy is by looking for “Rastafarian roots,” said Masters.
“We’ll see they look like actual dreadlocks on the plant. On that whole area around the root, the mycorrhizae will start to stick together.”
But many modern production practices — including overgrazing, tillage, and chemical application — reduce mycorrhizal levels in the soil. And because mycorrhizae are soil fungi, fungicide applications are perhaps most harmful.
“What do fungicides kill? Fungi,” said Masters, adding that producers will need to apply extra inputs to make up for the loss. “Who wins in that particular situation? Not you guys. This is why the net profit has been flat.
“If you’ve got a fungal problem, you need to be looking at soil health — not putting fungal treatments on seed. We need to stop the cycle of violence.”
By investing in soil health, not just inputs, producers can boost their bottom line and their productivity, while increasing the long-term resilience of their land, said Masters.
“If we don’t foster our underground workforce, then you have to pay for the services they provide for you. It’s going to come out of your pocket if you’re not looking after microbiology.”