14 ONTARIO GRAIN FARMER AGRONOMY Matt McIntosh Getting more for less Leveraging the interconnectivity of soil chemistry, biology, and structure for healthier soils and better crops Soil scientist and farmer Jill Clapperton provides insights on practical soil management strategies tailored to individual farm conditions rather than one-size-fits-all prescriptions. “Everything is connected. Everything we do starts with soil health.” Jill Clapperton, a veteran soil scientist and co-founder of soil health management company Rhizoterra Inc., shared that message with attendees at a soil and water health conference hosted by the St. Clair and Lower Thames conservation authorities earlier this year. She explained how farmers can tap the links between soil biology, chemistry and physical structure to improve crops and the environment. Clapperton said no two farms — and no two operators — are exactly alike, from ecosystem conditions to business risk tolerance. For that reason, she doesn’t believe in “prescriptions” for improving soil health. Below are highlights from her presentation on the science of healthy soils and considerations for individual operators. REDUCED TILLAGE Soil is a habitat. Tillage disrupts that habitat and can harm the organisms that live there, including earthworms, which help move nutrients and create channels for water to infiltrate. Tillage also weakens soil structure and increases the risk of erosion by wind and rain. Clapperton said the particles that leave the field include organic matter and the organisms that depend on it. “What we’re talking about today is soil as habitat. If you build it, they will come ... you can build it however you like,” Clapperton said. “But I’ll tell you right now: it’s all about reduced tillage.” AGGREGATE STABILITY Good aggregate stability and waterholding capacity help soil organisms move. Nematodes, for example, can’t burrow like earthworms and rely on water to reach the fungi and bacteria they prey on. That predation concentrates nutrients around plant roots, linking nutrient availability to water-holding capacity. “I hope you’re all looking at roots. It’s easy to walk around and look at the tops of plants, but often the symptoms below ground are far worse than what you see above,” Clapperton said. She added plants should use energy to “explore the soil,” not to push through a hardpan. “Good soil structure gives you more roots. In chemistry terms, it’s called metabiosis, when one positive change triggers another,” she said. “Then you recruit more organisms into the community, the whole system starts working together, and you get better soil structure.” “Sometimes soil can look great, but still won’t infiltrate. That’s about roots — getting roots down,” Clapperton said. “Your most readily available source of organic matter isn’t above ground; it’s below ground: the roots. Roots are breaking down all the time. The residue on top takes longer to break down and oxidizes easily. Roots are a major source of organic matter, and they leak many carbon compounds.” FEEDING FUNGI Clapperton said most soil fungi — about 85 per cent — are beneficial in some way. Mycorrhizae, which attach to plant roots, are “the original carbon traders,” she said.
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