By Darren Hefty
There is a growing adoption of cover crop use across the country. Even among those who are not currently using them now, many are considering them. There are many reasons to incorporate cover crops in your rotation. The question is often which mix to choose and how to get it seeded in time to maximize the benefits. When it comes to cover crops, here are four things you need to know.
Don’t Believe the Myths
Do cover crops use up water and nutrients so your next crop is terrible? That’s what I heard growing up and the contrary has proven to be true. Some of the areas where cover crops are being most widely and successfully used are in arid climates with marginal soils. Depending on the mix of cover crops you utilize, you can find crops that conserve moisture and even make nutrients MORE available for your next cash crop. Remember, you’re not harvesting a crop like you are with corn, for example, and hauling nutrients away. The nutrients the plants take in from the soil are recycled as you till the cover crop under or burn it down before your next crop is planted.
Use a Blend
So which cover crop do I pick? You’ll surely see ads and read articles supporting an individual cover crop, but don’t fall in love with just one. A blend is almost always the way to go in order to promote a healthy soil for microorganisms and crops as well as to accomplish multiple benefits you’d like to achieve on your farm. Almost any time we’ve encountered a problem stemming from a cover crop, it’s been when someone has planted a single cover crop.
A good example is with radishes. They are awesome for breaking up compaction, but they don’t act as a host for the mycorrhizae fungi that help make phosphorus available for crops. As a result of ONLY planting radishes in a prevent plant year, you may have purple corn or phosphorus deficiency showing up in your fields the next year.
Is There Enough Time?
How much time does it take to get the maximum benefit for your soils from cover crops? It really depends. In the case of highly erodible soils, your main benefit could be coming right away as soon as a stand is established and soil is held in place. If you’re looking for deep compaction breakup from a tillage radish, it would be great to have at least 60 days of growth out of your cover crop. The point is, you can choose a blend that offers a number of benefits and even if you’re in a corn/soybean rotation in the north there could be enough time for a cover crop to provide you with an economic return. You may need to aerially seed the crop or use an alternative planting method around late sidedress timing in corn to have a cover crop ready to grow quickly after harvest.
How Do I Get a Great Stand?
It’s easy to get a great stand planting cover crops after harvest when there is a timely rainfall event, but how about in the real world? Aerial seeding may change the cover crop you choose. For example, cereal rye seems to grow much better in this situation compared to oats. The keys are choosing the right crop, getting as much seed-to-soil contact as possible, and finally getting the seed in the ground with some kind of planter or sprouted and growing with a timely rain.