“Soil is the source of agricultural productivity,” says Purdue University agricultural economist Wally Tyner. “If we don’t take care of it, we’ll lose the tremendous resource we have.”
When researching conservation practices that were cost-effective at improving water and soil quality, Jasper County Soil and Water Conservation District Director and Conservation Programs Specialist Dan Perkins stumbled upon cover crops. Perkins is also an Indiana Certified Crop Adviser.
He found cover crops came up as the implementation that was not only the most cost-effective, but also the most readily adoptable. He has worked for the past 10 years to figure out how to communicate the yield and bottom-line benefits that cover crops can offer to farmers.
Cover crops are special
To Purdue Extension agronomist Shalamar Armstrong, studying soil science is critical to dealing with the grand challenge that agriculture is faced with: feeding a growing population. With the predicted population of over 9 billion people by 2050, agricultural productivity needs to increase by 40% to 50%, all while dealing with the depletion of farmland.
Prime U.S. farmland will continue to decrease, so farmers need to shift to increasing their productivity on the current available land. Armstrong believes cover crops are a key tool in accomplishing this.
After being in the crop scouting business for almost 20 years, Brian Wieland, Princeville, Ill., noticed the depletion of soil health in the fields he was scouting. He became frustrated with the way the soil looked. He had heard about cover crops, but wasn’t sure if they could help.
“When I started using cover crops, I found the organic matter increased, my water infiltration was better, and my soil looked better,” Wieland says. “I wanted to recapture my nutrients, and I’m using cover crops to accomplish that.”
He says he looks at cover crops as a sustainable, profitable conservation method.
What science says
Armstrong says the genesis of studying cover crops was all about solving soil erosion and improving soil structure. “From there, we began to understand that the cover crops not only reduce soil erosion, but they also increase soil structure and soil organic matter, which then increased the physical, chemical, biological processes that are going on in the soil,” says Armstrong. “This makes your soil till better and the soil health is better. Cover crops are also used increasingly to reduce the amount of nitrogen that is bleeding in the field.”
In addition to soil health benefits, the use of cover crops can reduce soil compaction. Cover crops are increasingly used to put nitrogen back into the soil, possibly lessening the need for anhydrous. Cover crops help increase water filtration, improve weed control and provide disease suppression.
Perkins is fully convinced of the science and has watched it play out in several field trials. “Cover crops are the gateway trigger to the average farmer pursuing soil health on his or her farm,” says Perkins.
Why farmers hesitate
There are three main reasons that farmers hold back from implementing cover crops: time, money and change. Mark Eastman, district conservationist with the Natural Resources Conservation Service, based in Tippecanoe County, says cover crops are another level of management to take on the farm, and he often hears, “It’s not the way Grandpa farmed.”
Perkins says the No. 1 reason he sees farmers hold back on planting cover crops is the inability to see the long-term view of farm profitability. Armstrong agrees that farmers have serious questions with the short-term benefits.
“Normally, when they use a practice, they’re used to being able to track that right to their wallet,” Armstrong says. “Cover crops are one of those practices that have a long-term, sustainable impact.” Some cover crop farmers have gotten it down to a science, though, and they know how much money and time to spend on their operation.
Josh Cox, Dayton, has used cover crops for over 10 years. His farm had issues with soil erosion and topsoil loss. Every year, he has increased his cover crop acreage. He agrees there can be times of failure and frustration, but overall he sees cover crops as a positive tool.
“Using cover crops has forced us to be better managers,” he says. “We have a heightened awareness of management due to the extra time that cover crops take.”
The next step
Armstrong says they’ve answered the question, “Can cover crops reduce what we lose?”
"Yes. Check. Thank you for telling me that my cover crops save me 50 pounds of nitrogen."
But farmers are now asking, “When am I going to get it back?” The next step in cover crop research is quantifying long-term impacts.
Purdue ag economist Nathan Thompson says cover crops have been around for a long time, but now it’s time to give farmers the research-based information from a reputable source.
“Expecting farmers to do something that you haven’t validated [is unreasonable]; this is their livelihood,” says Thompson. “The ultimate practicality — that’s what I do. You know, in addition to anything the engineers or the agronomists do, somebody’s got to put a number on it.”
Thompson and Armstrong are looking at how cover crops can help reduce the farmer’s No. 2 input cost by studying the biological effects of nitrogen when cover crops are in the system. The study is looking at quantifying nitrogen that’s not lost, and how much of the nitrogen in the cover crop is returning to the soil so the cash crop can use it.
Thompson says the tough part about cover crops is how dynamic they are. They’re a tool that grows in benefits, so quantifying the economics is a little more difficult. The process is not a year-to-year decision, but there are cumulative benefits that accrue over time.
He also notes that there are societal benefits, such as decreased nitrogen leaching, less need for inputs and increased viability of no-till. These can’t always be tracked directly to a farmer’s budget so you can say, “This is why you should implement cover crops.”
Adoption goes on
Yet, even without the economic research solidly proven, many farmers have already adopted cover crops. The have bought into the societal and scientific benefits. Wieland says farmers who are committed to cover crops don’t see it as an expense. They see it as a return. There’s a perception that it’s costly, but in reality, it’s not that costly. The returns are in soil savings and plant health.
“I’ve also seen farmers save big on herbicide cost,” Wieland adds.
Eastman adds that the Environmental Quality Incentives Program can be a huge asset to farmers who may be struggling with the economic feasibility of implementing cover crops. For the first three years of implementation, farmers can apply for cost-share to utilize cover crops to build organic matter, prevent erosion, reduce compaction and more.
“I have yet to have a non-cover-crop farmer see a soil pit with cover crop roots or a soil health demonstration and not walk away saying, ‘I want that on my farm,’” says Perkins.
Wieland and Holtsclaw are seniors in ag communication at Purdue University. They write from West Lafayette. Brian Wieland is the co-author’s father.
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