We've been having Café Talks on cover crops for prevented planting and it's led to some excellent discussions. Talking through ideas has really helped solidify approaches, so I'll share some of those ideas.
This article is going to be framed in the context of "why" we even want to do this, "what" we can do and how you just need to "trust your gut" and get it done.
Why are we seeding cover crops on PP? Since there is no cash crop on PP fields, we need to find a way to use moisture to prep it for a crop next year. Transpiration by plants is one of the best ways to move water throughout the soil profile (this means from more than just removing water from the surface) because roots extend deep into the soil. There is a good chance that if we don't use water this year with a crop, that the field will be PP again next year. We also need competition for plants we don't want in the field (herbicide resistant weeds). Also, if you're new to cover crops, growing them on PP can be a good way to get some experience and see what you like and don't like.
What's the plan? Each farmer and field will need a specific plan, but here are some general tips to get you started.
• Talk to your insurance agent and keep them in the loop on your plans. They may need to inspect the field and give you a date in late July or August that they can get that done. Talk with them about what you'd like to do and see if you can plant a cover crop before they inspect the field.
• Get your weeds under control before doing anything with cover crops. Double check your residuals too and make sure that what you are seeding will germinate.
• If you're seeding before July 15, you may want to do a simple grass mix of oats or barley and some millet or sorghum sudangrass (a cool season and a warm season).
• If seeding after July 15, and you're good with weed control, then you could add a broadleaf. This is where radish or dwarf essex rapeseed can be a good fit.
• You may not want the grass cover crop (or any of the cover crops) to head out or go to seed. So consider spraying it out before seed production. This will give you another opportunity to clean up any weeds too.
• If you want cereal rye as part of your plan, the time to seed it is after termination of the prior cover crop along with any weeds. By this time (likely August), you'll have some decent residue cover, have used some moisture and now you can add in the cereal rye because it will be cool enough. While you're at it, you can throw in a radish and maybe a legume (peas or faba), and flax could be a good fit, too.
"Trust your Gut" and get it done! One of the biggest setbacks to cover crops is indecision. If you keep your mix simple enough and rely on your innate ability as farmers to grow plants, you should be able to get it in the ground and check it off the list. Just stay in your comfort level-if it makes you nervous or stresses you out, then simplify.
A few final tips. There are a lot of PP acres, putting cover crop seed in short supply, so order your seed now. There may be a slight risk of seed being contaminated with weed seed. To double check, I will be sending my seed to the ND State Seed lab to be tested for germ and weed seed (nd.gov/seed).
So, kick around some ideas, get cover crops on PP ground and dig around in them often to keep learning.