Planting a fall cover crop can be the missing link for dairies looking to boost their feed inventory. While the benefits of cover crops include extending living roots, improved soil diversity postharvest, reduced soil erosion, and higher soil organic matter, being proactive in planting a fall cover crop can also help raise forage supplies for the following year. However, success depends on knowing what type, how, and when to use them properly.
Find your options
On an episode of Iowa State Dairy Extension’s “Dairy News and Views” podcast, Mark Licht and Shelby Gruss discussed how one of the most valuable resources dairy farmers have is utilizing cover crop fact sheets, which can be downloaded from the Natural Resources Conservation Service (NRCS). These fact sheets help dairy farmers know which cover crop to plant and when it should be sowed. They provide information on each variety, including its features, planting instructions, cultivating traits, and if they are labeled safe for grazing.
Licht, an associate professor and extension cropping systems specialist at Iowa State University, stated that the goal of these sheets is to “make sure you get the goal you’re trying for out of these cover crops.” For example, during a catastrophic event such as flooding, looking at a fact sheet can help dairies recover quickly by suggesting what to plant in this type of situation. “You don’t have to change all of your acres at one time,” added Gruss, an assistant professor and forage extension educator. Test a few acres and see which field benefits from what kind of cover crop. From there, you can work up to more acreage.
After harvesting a crop, such as corn for silage, there is a short window to plant a cover crop to ensure it gets established before overwintering. Licht and Gruss suggested planting turnips with a small grain after a silage harvest since those species will have enough time to grow. In general, cereal rye gives the best overall tonnage as it grows more rapidly in the spring compared to triticale or winter wheat.
Licht recommended overseeding in a raw crop stand as that is the best opportunity to get greater production in the fall. Another option is drilling postharvest, which can result in good seed-to-soil contact. A cover crop such as cereal rye could be planted in this instance, but most growth wouldn’t happen until spring. The success of both methods is dependent upon the weather.
Herbicide plans
The key in using herbicides on cover crops is planning ahead, the educators said. After picking your cover crop, check the herbicide labels for any carryover restrictions. “No one wants to kill something because you had an herbicide carryover situation,” Gruss emphasized. She also encouraged dairies to think ahead to what the crop rotation will be next time.
New research and data are ongoing with the hopes of having more answers to outlying questions about cover crops in the next couple of years. Gruss and Licht are proactively conducting studies to determine the actual impacts of using cover crops as a forage and digging deeper into the impact cover crops have on the soil. For now, dairies can count on fact sheets to help find the type of cover crop that fits their needs or goals, proactively plan ahead toward the next crop rotation, and collect yield data for comparison.
