By now, with winter around the corner, your cover crop is already going to work to secure topsoil from the erosive qualities of run off and wind. (If you don’t have cover crops on all your acres, it might be interesting to compare how bare topsoil, or even crop with residue laying on top compares with a health cover crop field.)
Annual ryegrass, researched now for more than 20 years (throughout the Midwest, parts of the East coast, upper south and into southern Canada), consistently ranks first among cover crops in terms of deepest roots. Why is that important?
- Deep mining of nutrients. After generations of plowing, the top foot or more of soil is depleted of nutrients and organic matter. Annual ryegrass roots access nutrients deeper in the soil profile, providing health to the crop but also limiting the amount of fertilizer inputs needed. The residual root mass, left after the crop is terminated in the spring, continues to feed the microbiology of the soil and create crucial organic matter.
- Compaction. Annual ryegrass roots grow right through compacted layers of soil. After the roots die each year, corn and soybean roots can follow the same channels created by annual ryegrass. Eventually, the compacted layer is so run-through with root channels, the compaction is completely permeable, allowing roots and infiltration of moisture.