To grow crops organically, farmers fight weeds with chemical-free weapons. One of the most common is a disk. Farmers rip out weeds and churn them into the soil with these disks. But it takes heavy tractors to do this efficiently, and large tractor tires compress the soil as they roll across the field. The process also depletes soil organic carbon, which plants depend on for nutrients, moisture, and healthy bacteria. And after a field is turned, heavy rains and wind can erode the exposed soil.