The channels left by plant roots, earthworms and other creatures can leave a valuable legacy in the soil, if properly cared for. These deep soil channels accomplish several valuable benefits.
“These channels are a legacy in the soil,” said Ray Weil, a soil scientist from the University of Maryland while standing in a soil pit in David Brandt’s field of more than 30 years of no-till and long-term cover crops. “The other roots are going to follow these channels down. It is like a highway infrastructure. When we built roads, it was where the Indian trails used to be. We don’t always understand what goes on underground because it is hidden from us. If you dig a pit on your farm, you’ll realize that these roots don’t just grow anywhere. They follow the old roots.”
More deep roots lead to more, deeper roots. Then, the deep undisturbed root channels allow soils to store more water in the wet spring and save it for the dry summer months. The channels also allow cover crops to reach down deep to pull available nutrients up to the surface.
“Deep soil nutrients are neglected resources under your feet,” Weil said. “Planting cover crops earlier allows them to grow deeper roots and scavenge significantly more nitrogen and other nutrients from deep down in the soil profile and make them more available to crops.”
The root channels make easy paths for corn and soybean roots to reach deep nutrients and water as well. And, in addition to the nutrients already there, the channels themselves are a source of more nutrients from worm castings and decaying plant roots.
Watch as Weil finds roots deep into the soil profile on Brandt’s farm.