Ask the Expert: how to make agriculture more sustainable
This article was written by Matt Davenport of the Michigan State University
MSU’s Bruno Basso outlines key steps the grain industry can take — with public support — to reduce its greenhouse gas emissions by more than 70% over the next decade
"Ask the Expert" articles provide information and insights from MSU scientists, researchers and scholars about national and global issues, complex research and general-interest subjects based on their areas of academic expertise and study. They may feature historical information, background, research findings, or offer tips.
Michigan State University Foundation Professor Bruno Basso has long been a believer in the power of digital agriculture. For years, he’s worked to show how emerging digital tools and technologies — things like drones, robotics, satellite imagery and computer models of soil and plant growth — can help farmers promote sustainability without sacrificing profits. Now, in addition to belief, he also has concrete numbers.
Basso, an ecosystems scientist in the College of Natural Science and the W.K. Kellogg Biological Station, has helped outline how America’s grain industry can shrink its carbon footprint by 71% by 2030.
The team — which included researchers at Duke University, the U.S. Department of Energy’s Argonne National Laboratory and Benson Hill, a sustainable food technology company — published its findings online on June 21 in the journal the Proceedings of the National Academy of Sciences.
Basso, who recently won a $250,000 award for sustainability innovations, sat down with MSUToday to talk about how farmers can achieve those reductions and how the public can help.
How big is this problem? How much of our greenhouse gas emissions come from agriculture?
The number varies, but basically about 14% of our emissions are a result of the way agriculture is managed. It’s a very strong anthropogenic source of emissions. But don’t forget — farmers are feeding the world. So we have to continue producing food, but do we always have to produce food at a cost to climate? No, we don’t.
And when we talk about improving the climate crisis, there are two things we need to talk about. One is pulling carbon dioxide, CO2, from the atmosphere and the other is stopping emissions.
Plants pull CO2, they do that for a living. So conservation and regenerative practices that you read about — things like planting more diverse crops and planting cover crops — that’s important and that will pull CO2 from the atmosphere and store it in the soil. But if we don’t address emissions and we continue to emit, we’re basically limiting our improvements. Soil accrual is not sufficient to completely revert the global warming trend. We need to do carbon accrual and reduce our emissions.
Your new paper focuses on grains in particular. How big of an emitter is grain production, especially compared to other ag sectors such as livestock, which tends to get more attention?
In general, 50% of that 14% of emissions comes from the fertilizer that we put on crops. Grains — corn, wheat and soybeans — cover more than 70% of the agricultural land in the U.S. All the other crops, although they’re important, they’re grown on very little acreage.
So where do the emissions come from? The biggest source is the production of fertilizers using fossil fuels through the Haber-Bosch process. When fertilizer is applied, it also emits a greenhouse gas in the form of nitrous oxide, N2O.
As a greenhouse gas, nitrous oxide is 300 times more powerful than CO2. The emissions of nitrous oxide are roughly 1% of how much fertilizer is applied. A farmer can apply around 200 kilograms of fertilizer per hectare, which would be 2 kilograms of nitrous oxide emissions. Those 2 kilos of N2O are equivalent to 600 kilos of CO2 emitted to the atmosphere. The footprint of these emissions is huge.
And let’s address the elephant in the room. Why do we grow so much? Humans can’t physically eat that much. We eat a little bit of edamame. We eat a little bit of corn on the cob. But that grain is really feeding another large and powerful system: meat and dairy; and the rest goes for bioethanol or biodiesel production.
There are emissions from livestock and that’s not going to change anytime soon. There’s going to be a demand for meat and dairy. If trends continue, the amount of corn we grow in the Midwest would just be enough to feed the chickens consumed in China.
So growing grains supports the meat and dairy production. People know about some of the emissions from livestock, the fermentation that happens in their stomachs and releases methane gas into the atmosphere. That’s an important greenhouse gas, too, but first, we have to solve the problem of fertilizer.
So how do we solve the fertilizer problem?
My work aims at informing farmers how and where to use the right amount of fertilizer.
Recently, thanks to digital technologies, we’ve been able to map and identify areas where fertilizer is needed — where the plants are using it efficiently — and other areas where plant growth isn’t limited by fertilizer, but by other factors: lack of water, shallow soils or compaction. So you have these areas that are constantly underperforming in terms of crop production. We’ve been watching these areas for years using images of the field taken from satellites, and we know they’re underperforming. But they’re still getting the same amount of fertilizer.
It’s like feeding a huge amount of pasta to a little kid. You know they only need a few grams, but you’re giving them kilograms. Why do farmers do this? Because it’s cheap. And it’s only been recently that we’ve been able to integrate these digital technologies together to give farmers a turnkey solution.
Today, we can retrieve images from satellites every day at high spatial resolution. Computer modeling has also improved substantially thanks to large quantities of data — Big Data. We now have models that look at the entire system — climate, soil, topography, crop genetics — in an integrated and an interconnected fashion. The final piece of the puzzle is the capability to apply fertilizer in precise amounts based on what plants need, which can vary from one meter to another within the same field. This has required new machinery, which is also on the trajectory to become fully electrical and autonomous.
The technologies are coming together now in a more complete way to offer farmers more complete advice. We can now tell farmers, "Put fertilizer here, don't grow corn there." We deliver prescriptions, like doctors prescribing medicine. We can help farmers vary the amount of fertilizer they use on the productive areas and recommend alternative crops in low productivity areas. The ultimate goal is to increase farmers’ profitability while reducing environmental impact.
The first part of the new paper is about digital agriculture and shows we can reduce fertilizer applications by 36% to get a 23% reduction in emissions without reducing yields. That’s just through matching fertilizer supply and demand on the field. This would also limit how much fertilizer runs off of fields to create water quality issues.
An example of maps showing different levels of crop yield (left), the associated profit or loss (center) and the application of precision conservation, with unprofitable areas replaced by native perennial grasses (right). Courtesy of Bruno Basso.
Along those lines, it can be easy to look at sustainability and profitability as competing ideas. What do you think of that?
People will say, “In order to be sustainable, you have to lose production and profitability.” Or, “If you want to push on the economics, the environment will pay the price.” That’s not true! Our research shows that we can reach a level of sustainability through more informed decision-making, by helping farmers do the right thing at the right place at the right time.
You talked about getting a 23% reduction by better management of fertilizer. How do we get to a 70% reduction by 2030?
That 70% is the potential and achievable ideal. It’s important to know that there are three phases to that goal. For phase one — which we talked about — we have the technology now. The next two phases are looking forward toward 2030. These are innovations in progress, but not available yet — things like electrifying the Haber-Bosch process instead of using fossil fuels. Ultimately, we’re calling for investments and for creating an agenda at the government level.
And you might ask, why would they listen to us? Because now we have the numbers. The unique thing about this paper is that we are reporting evidence. These are calculations with real numbers thanks to Argonne, a U.S. Department of Energy lab, that developed a model that quantifies the carbon footprints of the proposed novel technologies.
What are the obstacles that we need to overcome by 2030?
It’s complex. The problem is scientific, technical and social.
There’s a little bit of a barrier when it comes to accepting new technology. Farmers are bombarded by companies that sell pieces of a solution as an entire solution. Some of them have been burned by this before and they’ll hear me talking and think, “Here comes another one who thinks he can fix all my problems.”
And they have every right to say, “Listen, I’ve already tried this.” But this is not the same thing and we immediately catch their attention with our profit stability maps, maps showing areas that constantly make them money or cost them money. These maps are supported by scientific evidence that show them what’s happening and what they can do to fix problems. This is novel to them and we’re not selling anything. Rather, we’re aiming to help them see their farms using a long-term, systems approach.
We’re also working with early adopters who are becoming ambassadors of this integrated approach. Farmers trust other farmers — although, some are starting to trust some scientists more, too (Editor’s note: he said with a smile). Real, long-term evidence is changing their attitudes.
We also continue to expect farmers to take on all the risk. It’s easy for you or me to say, “Reduce how much fertilizer you’re using.” We’re risk-neutral. We can tell the farmers anything and the farmers will rightly say, “Ok, but I need to make a living.”
This is the paradox of agriculture. It’s a trillion-dollar industry and, while farmers do receive incentives, they’re living on very thin margins. Seeds are expensive, then there are pesticides, herbicides, all of that. The retailers, meanwhile, are making great revenues.
It’s not the best system for a grain farmer. The farmers are stuck in the middle and so I think the model needs to be flipped. Consumers maybe need to be willing to pay a little more for food that’s produced sustainably, and policy needs to help pay farmers to adopt new technology. If we care about sustainability, we could help farmers offset some of the risk and the cost.
The way we currently subsidize agriculture is through acreages allocated to a crop. Let’s say you have 100 acres of corn and along comes this professor at Michigan State who says, “Your field could really be 75 acres because 25 are not producing and are polluting the environment.” Under the current policy, farmers are not willing to remove corn acreage for alternative, native vegetation unless we reward them for this ecosystem services they’re providing with this change of practice.
Furthermore, by adopting more sustainable practices, farmers could enter a potential market for selling carbon credits or ecosystem service benefits. Rather than grains, they’re selling the benefits of crops that pull CO2 from the atmosphere and stores it in the soil without emitting greenhouse gases.
This is a way of doing agriculture. Success comes gradually, but that doesn’t mean we have to wait much more to achieve it.