Cover crops are great, but they won't save the world
Farmers just aren't planting enough of them, according to a new analysis from the Environmental Working Group.
If you’re trying to improve your physical health—whether you want to lose weight, gain weight, recover from serious illness, increase your energy, or run a marathon—I can almost guarantee the advice you seek from experts will include “drink more water.” It’s a simple strategy that delivers multiple, interconnected benefits, and it’s easy for most people to make happen without totally changing their lifestyles.
Planting cover crops is that strategy for improving environmental outcomes in farming.
Farmers put plants in the ground when their soil would otherwise be bare, and those plants hold soil in place to prevent water pollution. They can also crowd out weeds and add nutrients to the soil for fertility, potentially reducing fertilizer use and boosting crop yields. And healthy soil has the potential to boost carbon sequestration. Finally, unlike some other environmental farm fixes, they don’t require entire shifts in systems. Theoretically, farmers growing vast acres of corn and soybeans to sell into our current animal feed-ethanol-processed food system can plant them within their normal rotations (although there are some technical challenges).
For these reasons, all of the food-climate plans that are being talked about right now include them. Lawmakers and advocacy groups are pushing to put more federal funding into farm conservation programs; a lot of that money will go to planting cover crops. Businesses and politicians are drumming up momentum for carbon markets; those will pay farmers who plant cover crops.
Overall, we know planting them has very real benefits across the board, but there are many research questions that still need to be answered before we know how the practice might actually increase the amount of carbon stored underground on a long-term basis. What is clear is that if cover crops are going to help get carbon out of the atmosphere in any meaningful way, they’ve got to be planted all over the place.
Unfortunately, a new analysis from the Environmental Working Group adds to existing data that essentially suggests: that’s unlikely to happen anytime soon. The report found that in crucial Midwest states, farmers planted cover crops on only 1 of every 20 acres of corn and soy fields in 2019.
This week on The Farm Report, I talked to Soren Rundquist, the researcher who conducted the analysis, about what he found and how the report can inform current conversations around effective ways to improve farm practices. It may seem like a niche topic, but I guarantee you’re going to hear a lot about cover crops in the coming year, if you haven’t already.
I’m sharing the interview below. If you’d prefer to listen (while you cook dinner?) the podcast is available on Heritage Radio and Apple Podcasts, Spotify, and Stitcher.
Unwrapped
First of all, you specialize in GIS (geographic information system) mapping. Can you explain what that is and how it applies to studying agriculture? Of course. GIS (geographic information system) is essentially taking data points and applying a geography to those data points, in an effort to understand various phenomena. This report in particular is using a subset of GIS known as remote sensing, in which we use satellite imagery to observe the earth and what's happening in real time, more or less, on the landscape.
So you're actually looking at satellite images for evidence of cover crops? Exactly. So using satellite data, there's a variety of spectral bands in which you can manipulate to track the vigor of anything that's photosynthesizing. So trees, crops, grass, plants, etc. And the beauty of this analysis in the upper Midwest is that the landscape is very homogeneous and in the spring and the fall, when the cash crop is absent from the landscape, it's fairly easy to detect something that's greening in a landscape of harvested cash crops.
That's really fascinating. I didn't realize how much satellite data was used for this kind of analysis. Yeah, and one of the beauties of earth observation is that recently, there's more and more higher resolution and higher frequency revisits of satellite data that's more accessible to the general public through the United States government, as well as the European countries.
I want to get more into the exact analysis that you did, but before we do that...for people who are not farmers who might be listening, can you just explain what are cover crops and why are they important? Cover crops are typically cold season grasses or legumes planted directly on cash crops after the cash crop has been harvested. In the states we looked at—Illinois, Iowa, Indiana, and Minnesota—typically in the fall, the cash crop is harvested and then...an actual cover crop is planted. And when the cover crop is planted, that emerging vegetative cover will absorb any excess nutrients. It will keep that healthy soil and all that sediment on the field and protect it against massive snow melt, extreme rain, extreme drought, windy conditions. And ultimately, we think its number one selling point is that it's protecting water resources in and around these landscapes. So keeping those nutrients...and that soil in the field and out of water sources is very important, for healthy aquatic ecosystems, as well as serving healthy drinking water to millions of people.
So why did you decide to look at this particular question of how much cropland in this specific area is being planted with cover crops? What prompted this analysis? These four states...represent a lion's share of the corn and bean universe in the US. This region is known as the corn belt, and the four states account for around 68 million acres of corn and soybeans. So they're a substantial loading source for water resources within the Mississippi River basin watershed. And all of these states are also kind of top priorities for the USDA in terms of spending taxpayer dollars in the form of conservation dollars to grease the wheels, to get farmers and producers to adopt this voluntary practice on the landscape.
But we don't really have a good monitoring system in place outside of total acreage or total dollars spent over crude geographies like counties or states to really track how prevalent this voluntary practice is on the landscape. And it being voluntary, we'd like to see that if a farmer is being paid to put that cover crop on…their fields, they're going to be maintaining that practice as time goes on. So ultimately we're looking to track that persistence of adoption [to see] how many farmers are maintaining this behavior within a matter of five, six years.
Right. And does the satellite imagery that you're looking at allow you to look at specific moments in time, so you can look at a field during these months of this year and then look at it again at another point? Yeah. A lot of these states in the upper Midwest are often covered with snow once you get past December, but for this analysis specifically, we looked in November and December, when the cover crop would have been planted. And in some cases it'll kind of germinate over the winter and it doesn't necessarily emerge, so we'll go back and look the subsequent year, the following March or April to see, once the snow is melted, are we seeing this green up again? So it's a culmination of looking at months and months of satellite data within those windows.
Got it. So you looked at cover crop plantings in these four states. What were the main findings? The main thing we found was that across the 68 million acres of corn and soybeans in these four states, we detected around 3.2 million acres of cover crop. And we've done this survey in 2015 and 2017, and what we found was while we have still maintained some growth, the growth is starting to plateau. It's not very substantial. Those 3.2 million acres equate to about 4.8 percent of the total landscape being protected with cover crops. And that's somewhat alarming to us because with the nearly $77 million we've spent already in these four states to kind of grease the wheels for farmers to adopt this practice, we were hoping we'd see some stronger growth. It is important to note that we're not losing cover crop acres. All of the growth is slow and we've somewhat plateaued, but we're still growing slightly. But on a larger scale of substantially reducing nutrient loads, we're not anywhere close to meeting goals set by individual states on reducing nutrient loading to their surrounding surface waters.
You mentioned $77 million in federal funding. That’s a number that represents the amount of taxpayer money between 2015 and 2019 that has gone to planting cover crops through federal programs like EQIP and CSP in these states. I just was thinking about this and that's a lot of money, obviously, but there are also state programs that pay for cover crops, and there are non-profits that have partnerships where they're working with big corporations that pay additional incentives to plant cover crops. So that number is actually just a portion of the money being paid to farmers to plant cover crops. So, if all of that money is not leading to big increases, is paying farmers to plant cover crops a failing strategy, or is the investment too small? I'll do my best to kind of wade through the nuance of…what's informing these decisions [for farmers]. You're right that outside of federal subsidies, there are a lot of larger corporations and non-profits that are also trying to grease the wheels to plant more cover crops. But in these states specifically, we have seen in the previous two years a decline in USDA investment. So while it's not the only funding source in town, that decline could be related to seeing fewer acres on the landscape.
But there’s more nuance...in terms of adoption. If it’s an earlier winter than expected, once you harvest your cash crop and there's already snow on the ground, planting cover crops in some of those Northern states might be an issue. And other things like land ownership. In areas where we saw these gains and losses flickering, when we compare with other timestamps of when we've run this analysis, we see regions that are known for having high rental rates losing more cover crops. So I'm hypothesizing that could be tied to [if] you're paying top dollar for some land you're renting, you need a return on that investment. Taking the time to get in a conservation program might not be your number one priority if you need to take care of the cash crop itself to stay out of the red.
But I think there are opportunities to add some strings to these dollars. Some states are adopting more premium subsidy support or [tying it] to things like crop insurance. These smaller groups that are embedded in some of these states and are kind of at the forefront of cover crop adoption, they're actively doing these case studies to see which type of relationship with funding works the best for maintaining this practice on the landscape. So yeah, it's a complicated question.
One interesting point you made is the relationship between ownership and investment in things that will improve that land and conservation. Because if, if the land is not yours and you're not going to benefit from building healthy soil, if you don't even know if you're going to be on that land, that's a very different situation than if you're building the fertility of a farm that you plan on living off of over the long-term, right? Yeah. And there's been a lot of reporting recently about the increasing numbers of absentee farmland owners. Exactly. I don't think we have enough information yet [to know] if that's a number one cause of this, but it's an interesting question.
Another thing I wanted to ask you is: In terms of the environmental benefits and benefits for water systems, how important is it that these cover crops are planted year after year? Are we even getting any benefits if a farmer gets some money one year and is able to plant a cover crop, but then has two years where they skip it because it wasn't a good year, or, like you said, the weather doesn’t cooperate? It compounds the more persistently it’s maintained on the landscape in terms of reducing nutrients and protecting soil resources and building that soil health. I think you need an active rotation of cash crop to cover crop to really start to see those yield benefits, etc. I think if it's just going to be on the landscape for one year and then disappear...you're really losing that bang for your buck in terms of the investment into keeping those surrounding water resources clean.
Ideally, in a voluntary landscape, we'd love to see this be, you know, the number one practice in all these four states and the surrounding states, wherever you're growing cash crops near water resources. That would be really cool if we could get there. At this rate, I think we need to re-examine these mechanisms for funding and look for opportunities to reform or to add more carrots to [get farmers] staying with this practice longer.
Do you plan on repeating this analysis at any point? Or is this more of a one-time report? We've done it three times every other year, so 2015, 2017, and 2019. So I think, you know, internally we've had this conversation that since we're seeing this moment in technology when we can access these data more readily and can run algorithms on these data more readily, we'd like to get more frequent. Maybe annually or every other month or something tracking this persistence. So yes, the technology's there and we would love to to keep this going and grow the geography to include more states.
Are there other uses of GIS technology or other analyses that you're thinking about that you think could be used to help us better understand and implement agricultural climate solutions? Definitely. I could bore you for hours and hours on the cool datasets that are becoming more readily available that will allow us to examine this landscape more in a higher resolution. So things like looking at county-level rental rates and the acreage associated with rental rates…Or weather data incorporating, rainfall, snowfall, temperature data, growing days…Is the behavior of planting cover crops less persistent in areas that are more volatile in terms of climate? We’re starting to see more and more, in the upper Midwest, these extreme [weather] events happening more frequently. So they're greatly impacting the landscape and the behavior of folks planting these landscapes. I could go on and on, but those are just a few of the cool questions we can start to look into and try to correlate to see if there's any relationship between these contributing factors.
Still hungry?
“This is monumental.” For Civil Eats, I covered actions the Biden administration recently announced it is taking to shift more power away from meatpackers and toward small farmers and processors. Advocates for farmers (and eaters!) see the developments as a historic step forward to address consolidation in beef, pork, and poultry that hurts farmers, rural communities, and consumers, but the path to implementing the reforms is likely to be rocky and some question whether the administration will stay the course.
Currently devouring
Food for thought? Zadie Smith’s collection of short stories,Grand Union, is not about food, but I finally started reading it this week and it’s so good, I just want to tell everyone about it. If you need some summer fiction, I highly recommend picking it up. One story in particular—The Lazy River—blew my mind. In that one, she does throw in some commentary on food preference and value judgments: “There is nobody French or German here to see us at the buffet, rejecting paella and swordfish in favor of sausages and chips…” And my favorite part of the story incorporates my favorite vegetable (I know…fruit!): “The ladies get to work. The men are in the polytunnels. The tomatoes are in the supermarket. The moon is in the sky. The Brits are leaving Europe. We are on a ‘getaway.’ We still believe in getaways.”
Actually eating
Speaking of tomatoes…they have finally ripened in the Mid-Atlantic and I will be gorging myself for the next month (or two). This is a photo of some heirlooms I helped harvest yesterday at Karma Farm. I had a giant tomato salad on Tuesday. Last night, we had BLTs and pasta salad (with cherry tomatoes!) for dinner.
Let’s be friends
Share all of your tomato recipes (or anything else) with me, please, on Twitter and Instagram. See you next week!