"What's strange about that, the harvest is in?" you might ask.
Well, for many years now cover crops have been a topic of discussion and the farmers and land owners experimenting with the practice have had great results - including yield increases, improved soil health and less erosion. And year over year the data shows more and more growers are using them. But by now, I would have thought there would have been a rapid adoption of cover cropping almost everywhere, along with more and more using no-till practices. The combination can add $100/acre profit!
Here is an email conversation from several years back where I was sharing with my supervisor about cover crops and soil health...
"Part of my performance plan is to share insights of the soils classes I’ve taken and how that relates to our work here.
I have not taken much time for the online classes since the cover crop workshop, but here is a quick video to share from the USDA NRCS that kind of ties together soil health, the industry’s renewed push for biologicals and our company's beginning interest in cover crops."
Thanks for sharing, Jeff! Your interest in sustainability brings another dimension to how we think about agriculture and that is always a good thing.
The expert in the video mentions diversity of crops is best for soil microbe health. Do you think that simple crop rotation is enough to do this? Crop rotation has been a best practice, however I understand sometimes this isn’t done. So are cover crops used in the winter in soy and corn fields? Or are they planted somewhere else?
I don’t know percentages of acres growing continuous corn vs corn-soy rotation. Some growers have also included oats or alfalfa in a multiyear rotation plan, but I think those numbers have really decreased.
However simple crop rotation is not enough for good soil health and conservation. The large amount of time the soil is left exposed to the elements contributes to erosion. Nitrogen off gasses from soil >50°F, the gap from harvest until the soil cools and from warm up to the new Spring growth; fields can lose much of the added benefit if anhydrous or manure is applied at these times. Probably the biggest effect on overall soil health is that the rhizosphere is left without living roots. These are an important piece in the soil food web.
Cover crops are a really great step to bridge the gaps between growing seasons in corn, soy or other annual crops. Late summer aerial seeding into existing stands, planting cover seed at harvest or soon after can have good results too. Cover crops keep the soil biome active (although its much slower in winter) by sustaining the microorganisms with living roots. They also protect the soil from exposure, and the roots help hold soil in place. They take up nutrients and store them in their tissues until released through decomposition post termination.
Use of cover crops is growing but adoption has been quite slow. The combination of no-till and cover crop systems takes ~3years to get established and that plays a big part I think, especially on leased farmland.
If you have more questions just ask, I really like talking about it :)
Spread the word about Cover Crops!
Thanks for the extra information, Jeff! Cover crops sound like a good tool to use. Hopefully they will continue to gain ground :)
Read more on the "Economics of Cover Crops" from Ohio State University
I encourage you to consider cover crops, or talk to your friends and neighbors that haven't. These are one way to help our soil, water and environment without a major change to a conventional corn and soybean operation. Resources are available to assist you through the USDA NRCS, USDA SARE, Practical Farmers of Iowa and more.
Have a great week!