When talking soil, often the topic focus is on soil type, nutrients, moisture, or microbiology.
But what about soil structure?
As Steve Larocque, Alberta farmer and founder of Beyond Agronomy explains in this Soil School episode, the physical types of soil can’t be changed, whether it be sand, silt, or clay. However, how land is managed can change the porosity and structure of soil. The way to do that, according to Larocque, is through controlled traffic farming, or CTF.
Controlled traffic farming is when a farmer ensures all equipment operates on the same — or multiples of the same — axle width. This creates tram lines across the field — the only spot where tires will drive, concentrating compaction on one area.
“The premise of what we’re trying to accomplish is just increasing the porosity of the soil, so it can drain, and it creates a whole bunch of condo space for biology to live,” he explains. “If it’s too compacted — which these clay soils can be, because [this field here] is a 70 per cent clay soil.” (Story continues below video)
“It really helps to open up that soil and build resilience. When it’s really wet — we still perform. When it’s really dry, we still perform,” he says.
One of the questions that often comes up with CFT is about those tracks that get compacted down over and over, and the loss it potentially brings to the field.
As Larocque explains in the video above, they give up 17 per cent of their land base to wheel tracks, which is a lot; but concentrating the compaction in one area means other areas grow without the constraints of compaction and out-perform non-CTF fields.
“Even though this little tram line is hard as a rock, versus beside it, the outside rows will actually — and we’ve done yield tests like one meter a row, count the heads, weigh the kernels, that sort of thing — it’ll actually yield almost 50 per cent higher in these outside rows to make up with the additional light and additional water.”