ONTARIO GRAIN FARMER AGRONOMY 25 work, Zehr says he tries to “work on the assumption there is abundance” in soil, rather than adopting a scarcity mindset. “Nitrogen isn’t just a fertilizer, it’s a cycle. Healthy biology is what turns nitrogen into a reliable, season-long nutrient supply,” he says. With this in mind, Zehr says growers should look for ways to add carbon, oxygen, silica, and micronutrients to support enzymatic activity. Feeding the carbon cycle and improving soil structure with living roots and residues is one way to achieve gains, he says. Understanding the importance of trace elements and micronutrients is another. Silica, for example, is critical to plant metabolism. Molybdenum relates directly to nitrogen use efficiency and nitrogen fixation. Boron is critical for pollen viability, pollen tube growth, flower retention, seed set, root growth, and hormonal regulation. Zehr says his experience shows molybdenum and boron are consistently neglected in Ontario, often to the point of critical deficiency, resulting in “constipated plants” where nutrient flow does not reach its full potential. Another strategy for improving the natural function of soils is avoiding fertilizer overapplication. “Adding nitrogen can suppress biological fixation. It’s kind of like labour — when you have too many workers, the organisms say, ‘OK, we’re done.’ We have to figure out a system that’s going to work with the natural system in our soil,” Zehr says. The end goal is for soils to “regulate themselves,” reducing dependence on expensive inputs. “The soil and plants are a heck of a lot smarter than we are. Nature has the blueprints to do it. We’ve simplified complex systems to simple chemistry. It’s shooting ourselves in the foot and wondering why it hurts to walk.” Zehr also encourages farmers to sharpen their observation skills and pay closer attention to how plants respond to management practices, rather than relying on linear assumptions between inputs and expected results. “Observation is so critical for farmers. They spend so much money paying agronomists like us to do tissue tests and soil samples, and then we give them recommendations. But what we’ve seen is that not many are taking these analyses, going out into the field, and watching how plants express themselves,” he says. “My dad always said growing up on the farm that plants are an amazing thing to work with because they’re the one thing in life that won’t lie to you. When you do the right thing, plants will respond positively. We have all this analytical data now, but we can simplify so much of it with observation.” • Photo: Matt McIntosh Gordon Alblas holding two silage corn plants grown with reduced nitrogen rates.
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