For the InstructorThese student materials complement the Future of Food Instructor Materials. If you would like your students to have access to the student materials, we suggest you either point them at the Student Version which omits the framing pages with information designed for faculty (and this box). Or you can download these pages in several formats that you can include in your course website or local Learning Managment System. Learn more about using, modifying, and sharing InTeGrate teaching materials.
Tillage Impacts on Soil Health
In addition to exposing soil to wind and water erosion, tillage can alter the physical structure, distribution of organic matter and biological activity of soil. At the depth where the plow impacts the soil, a layer of soil compaction can develop (a plow pan), limiting water infiltration and plant rooting depth. Under tillage, crop residues, roots and root hairs and their associated fungal hyphae are disturbed and more decomposed in the plow layer. By contrast, when roots, fine roots, and fungal hyphae are not disturbed and decomposed as rapidly, there are more channels that water, air, earthworms, and roots can move through, and soil aggregation is enhanced. Below is a schematic comparing the root zone profile of a conventionally tilled soil to a no-till soil.
Credit: S. W. Duiker and J.C. Myers. 2005 Penn State University.
Watch the three videos below, from USDA NRCS about soil tillage and soil health.
Video: The Science of Soil Health: What Happens When You Till? USDA NRCS (3:05)
Video: The Science of Soil Health: Nightcrawlers and Soil Water Flow. USDA NRCS (3:05)
Video: The Science of Soil Health: Compaction USDA NRCS (4:26)