Cover Crops: What’s the Payoff?
This season’s crop seems to be more high maintenance than other years, we are facing more rain, again, and windy days limit our spraying and other work. We’re fortunate that we have all our ground planted; there are some farmers who have been rained out several times and are trying to catch up.
It’s years like these that remind us that farming isn’t about one year’s performance. While we want every crop to exceed our expectations, it’s a fact that it doesn’t always happen. What worked well one year may not the next, simply because Mother Nature has her own ideas.
Trends change too. The agriculture industry continues to develop new practices with an eye toward improvement. It isn’t the corn standing in the field that is the most valuable, it’s the soil beneath it. We use the no-till method, which is a good way to limit erosion especially during the winter months when there isn’t a crop planted. Many people underestimate wind erosion. A great way to see that in action is during the winter. If you see dirty snow, you realize the dirt came from an empty field. If you drive by a field that’s no-till with a cover crop you won’t see that.
Crop rotation practices here in the Midwest are usually corn-beans-wheat-corn. Rotating them prevents depletion of the nutrients in the ground. While we also apply topical fertilizer, it’s the richness of the soil that is most important.
Are Cover Crops a New Trend?
About ten years ago, the idea of planting a cover crop came into practice. It’s been something that we began to experiment with. Basically, a cover crop is a non-cash crop planted solely to protect the soil from wind and water erosion with the added benefit of replenishing bio-nutrients.
Sounds good so far, right? In the long term, it provides a desirable outcome in terms of soil improvement; in the short term, it’s an investment that requires consideration in years like these. Planting a cover crop could add $20 per acre in costs and in a year where the commodity prices are low, it could eat up the already slim profit margin. Mathematically, it’s difficult to directly correlate an improved yield to the use of cover crops on a year-to-year basis.
Beyond an added cost, cover crops can sometimes shorten the planting window in the spring. Corn is best planted in warm, dryer soil and a cover crops’ root system is holding water and slows the warming process. The common Indiana mentality is to keep fields clean (not a lot of weeds) so they warm up fast in the spring.
What “Crops” Are Cover Crops?
Farmers have used a variety of cover crops, such as clover, vetch, rye, Australian winter peas and even turnips and radishes. Each has its benefits, but they also require specific timing in order to germinate before the winter months. If it’s a late harvest season, then some of these options aren’t viable for that year.
Peas, which are legumes, are ideal for replacing nitrogen in the soil. In fact, they can add enough naturally that adding additional commercial nitrogen the following spring isn’t necessary.
Over last winter, we had about ten percent of our ground planted in cover crops. We planted cereal rye in harvested cornfields. This spring, we sprayed the rye before planting soybeans. The rye melts down and acts like a mulch around the beans. Not only did it help to preserve soil nutrients, it suppressed weeds due to the mulch effect.
So What’s the Bottom Line? Are Cover Crops Good or Bad?
Whether or not it’s the economical thing to do, we plan to continue using cover crops. It’s a slow learning process as we experiment with various products. It’s an investment in our future as the soil is replenished and the biological elements (earthworms and other insects) do their work. I hope we keep refining the details as we go and 10 years from now the majority of our land has cover crops on it.