Ways to Reduce Tillage
“The more you till, the more you break up soil structure,” explains Jodi DeJong-Hughes, an Extension educator at the University of Minnesota. “The least amount of tillage you can do, the better.”
Why does tillage break up soil structure? You might need to be a soil scientist to understand the full answer, but the short answer is that tillage oxidizes the organic matter in soil. This destroys the roots and active organic matter that give soil porosity, causing the soil structure to crumble and compact. In healthy soils, 50% to 60% of the soil is porous, while a compacted soil porosity can be reduced to 30% to 40%.
DeJong-Hughes’ solution to cutting back on tillage is to start small. “If you are attached to your chisel plow, there are ways to make that less aggressive,” she says. “You can change out shanks and still get tillage, yet leave more residue and not destroy the structure as much as more aggressive implements. Certain implements are more detrimental, like disks. Disks destroy structure. That’s why we use them to build roads.”
As part of her work with the University of Minnesota Extension, DeJong-Hughes visits farmers and digs soil pits to examine soil conditions. “Anytime I dig soil pits in farmers’ fields, they know where those spots are for years because they’re mushy. That’s because the soil structure was destroyed,” she explains. “I never make the pit wider than the tractor, because the tractor would sink. That’s how important soil structure is.”