Cover crops are no longer just a conservation practice, but an integral part of the crop management system, specifically targeting the soil health-management element. This continued momentum also fuels considerable discussion.
Why are farmers investing in cover crops? Do the benefits outweigh the costs? What are the main benefits farmers seek from those plantings?
Straight from the farmer’s mouth
Missouri farmer Johnny Hunter says he has observed five reasons more farmers should consider adding cover crops to their farming operation.
1. Reduced Inputs
“We lean on our cover crops to scavenge nutrients and fix nitrogen for our cash crops,” says Hunter. “Last year, our cover created 74 pounds of nitrogen per acre, or the equivalent of $28 per acre according to our soil nitrate testing. The more nitrogen we can produce through cover cropping, the less we have to purchase.”
Hunter’s cover-crop mix included cereal rye, crimson clover, hairy vetch, red clover, annual ryegrass, daikon radish and black oats, all in different combinations depending on the situation.
2. Savings on Herbicides
Cover crops provide natural weed suppression that allows Hunter to forgo some of the herbicide applications he has to make in his non-cover-cropped fields.
“I see the cover crops almost like a residual herbicide,” Hunter says. “I let my cover grow big and tall so that it forms a blanket of biomass that keeps weeds from emerging. We also plant cereal rye that has allelopathic properties that reduce pigweed populations. The cereal rye has helped us dramatically reduce pigweed in our fields.”
3. Enhanced Water Infiltration
Hunter uses moisture monitors buried 4 inches, 8 inches and 12 inches deep in his fields to help determine when his crops need irrigation.
He’s found his cover-cropped fields do a much better job of absorbing rainfall than his fields without cover.
“A half-inch rain usually only shows activity at the 4-inch level in our fields where we haven’t planted cover crops,” says Hunter. “We’ll see water reaching all the way down to our deepest sensors in our fields with cover. The tiny fibrous roots of the cover crops really help water find its way deeper into the soil and greatly increases the soil’s water-holding capacity.”
The enhanced rainfall infiltration and moisture retention of the soils in his covered fields allows Hunter to reduce his irrigation costs.
4. Erosion Control and Runoff Prevention
“Cover crops protect our soils from blowing and washing away with their living roots that help to hold the soil in place,” says Hunter. “The cover also shields the soil from direct contact with rain droplets, preventing soil particles from detaching from the surface, where they are more susceptible to erosion.”
5. Improved Profitability
“The fields we’ve cover cropped have healthier soil profiles and more consistent yield,” says Hunter. “They’re less volatile and we don’t see wild fluctuations in production. That consistency results in better yields and higher profits.”
Think outside the box, but do your homework first
Incorporating cover crops into a farm’s overall crop management strategy will provide a multitude of benefits, but it’s not a “one and done” or a “plant and walk away” type of practice.
For a successful cover crop experience, some up-front planning and goal setting should be part of the overall strategy to help ensure you meet your priority objectives. Cover crops require an investment of time and money, all of which coincides with the hectic harvest and planting season. It can all become a bit overwhelming.
It’s important to think strategically about cover crops and how they best fit into a given farming operation to ensure that the benefits received justify the time and investment.
One thing heard repeatedly from farmers is that the successful transition to using cover crops involves a learning curve and out-of-the-box thinking.
Every farm is different.
First-time cover-croppers should start small and learn first-hand what works (and perhaps more importantly what doesn’t work) on his or her own farm. Priority number one should always be getting the cash crop successfully planted. Starting small will minimize planting risks and maximize successful long-term implementation.
Determine up front your key objectives for using cover crops.
This helps you measure results afterwards and guides certain decisions you will need to make on the front end. Certain objectives will influence your decisions.
For example, selecting the right cover crop species (or mix of species), the right seeding rate, planting method and timing, as well as termination method and timing, all play a significant role in meeting different objectives.
In South Africa we have a lot of companies selling cover crops, but they not eager in marketing their products or make information available.
