Many farmers planted a full season cover crop on their prevented planting acres or are out there now planting a winter annual, like cereal rye. This is a great management approach because you’ve either managed water in those fields similar to what you would have done with a cash crop or you will be managing water next spring with cereal rye planted this fall. Your field is better prepared for 2021 than if you didn’t seed a cover crop on your prevented planting in 2020. So, let’s talk about how to manage these fields this fall or next spring, based on comfort level and resources.
If you are fortunate enough to be in one of the counties where the grazing date on cover crops planted on prevented planting acres was pushed earlier to Sept. 1 and you have access to livestock, then you are likely grazing those covers and have your plan in place. Cattle will do wonders for managing the amount of residue in the field. If you aren’t grazing the cover crops, you still have plenty of options.
First, if you are getting uncomfortable with the amount of growth, you can either get a sense of relief that some of your cover crops will frost kill with the colder temperatures or you can terminate with a herbicide. Any warm seasons in the mix will likely die back with a drop below freezing in the evening, especially plants like sorghum sudangrass. You may also see some of the cool seasons, like peas, frost kill. Cover crops like radish, turnip, kale, faba bean, barley or oats will not likely die with temperatures hovering around freezing. They will need colder temperatures for a longer duration. So, if you have concerns, a herbicide application can be helpful.
If conditions are still wet and you’re not worried about the growth, then let your cover crops keep growing. If you have a lot of radish or turnips in the mix, keep in mind that much of that biomass will be pretty minimal in the spring. The grass part of the mix will be more of the residue that you’ll be planting into in the spring. Make sure that you get your equipment ready to plant into that residue in the spring or you can do a vertical tillage pass this fall or in the spring to help manage some of that.
I do not recommend a pass with a chisel plow or a ripper on these fields. Not only will you damage the soil structure you’ve built and root channels that will help water move into the soils next spring, you will create a mess. Big radish roots and turnips decompose much better in the soil rather than on top of the soil. So, let them be and manage in the spring. Standing residue is also better than laying it down and creating a mat, so keep that in mind also.
As you go through the winter, talk to others who have used cover crops to get some tips and to ease your mind. If you have experience using cover crops, be sure to listen to those asking you about how to manage these fields. By listening and then offering advice or talking through options, you are more likely to help instead of discourage or add to anxiety over a new practice.