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How technology is helping farmers grow more food with less chemicals

Regulators, consumers, and farmers want to use less chemicals to grow food; chemical companies are changing their business models in response

by Matt Blois
May 7, 2023 | A version of this story appeared in Volume 101, Issue 15
Two tractors spray herbicides across a uniform green field.

Credit: One Smart Spray | An early prototype of a sprayer developed by a joint venture between Bosch and BASF combs through a field. The machine aims to reduce chemical use by spraying only weeds rather than the entire field.


In brief

The overuse of agricultural chemicals cuts into farmers’ incomes, generates tons of greenhouse gas emissions, and represents a major source of water pollution. Some companies say they can solve these problems by using drones, satellites, and artificial intelligence to give farmers a clearer picture of what’s happening in their fields and help them apply only the chemicals they need. Proponents of this approach argue that it has the potential to dramatically reduce the use of chemicals on farms. In response, large agricultural firms are shifting toward a business model in which farmers pay for the outcome, such as a field free of weeds, rather than a specific chemical. These tools could make the food system more secure and less harmful to the environment. But they won’t have any impact if farmers don’t adopt them.

Jon Walz’s century-old farm in Stapleton, Nebraska, has 300 head of cattle, corn fields, and other crops, including oats and rye. On a recent morning in April, the whole farm seemed to need his attention after temperatures abruptly swung from frigid winter lows to sweltering summer highs.

Walz brought a sick calf and its mother into a corral, attended to several pieces of irrigation equipment that needed maintenance, and started setting up an herbicide sprayer. “There’s just a lot of things happening on the farm right at the moment,” he said while checking to see if any of his other cows were giving birth.

As part of a recent push to make the farm more sustainable, Walz has added another item to his to-do list. He’s testing several technologies that promise to reduce his use of nitrogen fertilizer and the associated environmental impacts.

Last year, working with researchers at the University of Nebraska-Lincoln, Walz attached a sensor to his tractor that measured the greenness of his crops as he drove over them. The sensor identified which parts of his field already had enough nutrients. By applying less fertilizer in those areas, he cut his nitrogen use by 32%.

“Sometimes it’s expensive,” Walz says of the technology. “But I think the opportunity to be more efficient using that technology, as long as it’s reasonably priced, is there.”

The overuse of agricultural chemicals, such as fertilizers, herbicides, and other pesticides, cuts into farmers’ incomes, generates tons of greenhouse gas emissions, and represents a major source of water pollution. Regulators are pushing farmers to cut their chemical use, but farmers also need to grow more—at least 35% more than they did in 2010 if they are to meet the food needs of the world’s population in 2050, according to one recent analysis published in the journal Nature Food (2021, DOI: 10.1038/s43016-021-00322-9). Some farmers are now trying to grow more food with less chemicals by adopting technologies that apply them only when and where they are necessary. Like Walz, many growers are using in-field sensors or aerial imagery to map the nutrients a crop needs and apply them more judiciously. Others are using sprayers equipped with cameras that can pinpoint weeds and kill them with a targeted shot of herbicide rather than a blanket of it.

These techniques are also transforming the companies that make fertilizers and pesticides. In the future, instead of selling as many tons of chemicals as possible, companies say they will provide farmers with a suite of software, machinery, and chemical products to maximize a farm’s profitability.

That’s a monumental and difficult shift for an industry that for nearly a century has made money by discovering, manufacturing, and selling large volumes of chemicals. And it will likely require a new business model, one based on how much these new tools help the farmer, says Niall Mottram, who leads Cambridge Consultants’ agricultural technology business. “Rather than selling pounds of fertilizer, they’re wanting to sell outcomes.”

Nitrogen fix
The amount of nitrogen used to grow crops in the US has more than quadrupled since 1960.
A graph showing the steady increase of nitrogen fertilizer use from 1960 through 2015.
Source: US Department of Agriculture.

For Walz, technology is only one part of a strategy to transition his farm toward more regenerative agricultural practices. In addition to mapping how much fertilizer his fields need, he’s using more cover crops—plants that improve the soil but aren’t harvested—to add nitrogen and suppress weeds. Walz believes that combining these approaches will make his farm much less reliant on chemicals.

“We’ve got a few fields where we haven’t used Roundup for several years,” he says of the ubiquitous herbicide. “That’s the direction that we’re going to be pushing. I think it’s more than possible.”

Fertile ground

Synthetic nitrogen fertilizers were introduced on US farms in the middle of the 20th century, and their use increased steadily until the 1980s. Since then, they’ve been applied consistently to nearly all the corn grown in the US. Those extra nutrients significantly boost farmers’ yields, but they can harm ecosystems and human health when excess leaches into the environment.

Each summer, fertilizer runoff contributes to a massive oxygen-poor zone in the Gulf of Mexico that’s unable to support marine life. One recent study published in Environmental Health estimates that 5.6 million people in the US drink water with dangerous levels of nitrates, partly because of pollution from fertilizers (Environ. Health 2019, DOI: 10.1186/s12940-018-0442-6). The production of nitrogen fertilizers in particular is also a major source of greenhouse gas emissions.

You are not selling the liquid in the bottle anymore. You are selling the results in the field.
Rachel Rama, head of small molecules, Bayer Crop Science

Part of the problem is that farmers typically apply the same amount of nitrogen to every part of their land, even though the nutrient needs within a field usually aren’t uniform. That means some parts of a field receive too much nitrogen, while other parts don’t get enough. Farmers also apply phosphorus and potassium fertilizers, but these nutrients can build up in soil over time, so precision is less important.

“Being more surgical and efficient with our nutrient applications means less of that impact on our water supply and in our aquatic systems and fisheries,” says Steven Mirsky, a US Department of Agriculture research ecologist who studies agricultural technology.

A digital map showing the greenness of different areas of a farm.
Credit: Ninja Ag
Ninja Ag uses images captured by drones or satellites to measure the normalized difference vegetation index (NDVI), a ratio between red and near-infrared light reflected off the field. Higher values, shown in green, typically represent greener plants, while lower values, shown in red, may represent yellowing plants, bare ground, or very wet areas. The company uses these data to identify which parts of a field need fertilizer.

The challenge is figuring out exactly how much fertilizer each part of a field needs and when to apply it. In 2018, a group of agricultural researchers from Oklahoma State University formed the start-up Ninja Ag to help farmers answer those questions using aerial imagery.

The company, which started operating commercially in 2021, first asks farmers to apply an ample amount of fertilizer to one strip of a field, which will serve as a reference point for the healthiest possible plants. Ninja Ag then analyzes an aerial image of the farm captured by drones or satellites, comparing a measure of greenness—a proxy for chlorophyll and thus plant health—from the reference strip with that measure from the rest of the field. Farmers use a handheld greenness sensor in a few areas to calibrate the readings from satellites or drones, making the data more precise.

The data are loaded into a formula that considers the farm’s location, the weather that season, and how big and green the crop is. The formula generates a map recommending the best way to apply fertilizer.

As proof that Ninja Ag can help farmers apply nitrogen more efficiently, CEO Courtney Arnall points to Brent Rendel, a farmer in Oklahoma who says the system reduced his overall fertilizer use on his most recent winter wheat crop.

Without Ninja Ag’s system, Rendel says, he would have used far too much nitrogen in multiple fields. There were also areas of his fields where the system said his typical flat rate of nitrogen wouldn’t have been enough. “I had fields that needed almost nothing and fields that needed a lot,” he says.

Other companies are getting closer to the plants to measure how much fertilizer a field needs. The start-up Autonomous Pivot mounts nitrogen sensors on irrigation pivots, the rotating metal scaffolds that arc over a field and drip liquid fertilizer and water on crops.

The company divides the field into slices and recommends how much fertilizer to apply in each one. While dripping fertilizer from above, the pivot moves faster over slices that need less and slower over slices that need more. The system is already available for potato farmers, and the company hopes to move into corn next. CEO Yuval Aviel estimates that the system can reduce fertilizer use by 10–20% without cutting into yield, compared to conventional fertilizer management.

Another company, Arable, gets even closer to the crop. It sells a device that looks like a lamppost rising above a field. The post is packed with sensors. A camera on the underside looks down on the crop and measures greenness, while a sensor in the ground monitors soil moisture and temperature.

CEO James Ethington says having a sensor positioned directly above a crop at all times helps farmers spoon-feed their plants fertilizer throughout the growing season rather than apply a large amount at the beginning of the season, when it’s more likely to be wasted.

Weed killers
US farms' use of herbicides increased rapidly during the second half of the 20th century, peaking in 1981.
A chart showing the amount of herbicide used on US farms between 1960 and 2008.
Source: US Department of Agriculture.

Farmers without the tools to determine exactly how much fertilizer their crops need will generally apply more than they think is necessary as a form of insurance, Ethington says. Applying extra fertilizer costs farmers more, but it protects them from the risk of using too little fertilizer and missing out on a huge harvest. “We’ll put better tools in the hands of the farmer so that they can better see and decide what they actually need,” he says.

Right now, Arable’s devices are used mostly by large food companies that operate their own farms and by big chemical companies, which use them to monitor field trials for new varieties of seeds or pesticides. The company hopes to start selling more devices to traditional growers.

Laura Thompson, a researcher at the University of Nebraska–Lincoln, says such systems can help farmers save significant amounts of fertilizer, but each farm is different. There’s no one-size-fits-all approach, she says, and it’s important for farmers to find the technology that’s most appropriate for their land.

“We would expect more benefit from these technologies when we’re in fields that are more variable, compared to a uniform field where a farmer’s traditional, uniform, flat management would be fine,” Thompson says. In some cases, a new technology could recommend the same overall amount of fertilizer as the farmer would have otherwise used, she says, but it might recommend distributing it in a different way to increase production.

Smart sprayers

In the US, most corn, soybean, and cotton farmers apply a blanket of herbicides to crops that have been genetically modified to tolerate them. Many farmers love the simplicity of this system, but it also means that most of the herbicide they’re spraying is simply wasted on the dirt.

In addition to damaging native plant life and threatening water sources, the overuse of herbicides has led to the evolution of weeds that can tolerate these chemicals. These herbicide-resistant plants have forced farmers to use more chemicals to control weeds, increasing the chances that new herbicide-resistant weeds will emerge. Farmers are desperate for new herbicides to escape this vicious cycle, but some companies say making smarter machinery to apply the chemicals is another way out.

“I think if you go out in 20 years and say, ‘We were spraying contact herbicides even where there weren’t weeds,’ people will think, ‘Why were you ever doing that?’ ” says Matt Leininger, who leads the North American division of One Smart Spray.

The equipment manufacturer Bosch and the chemical company BASF formed One Smart Spray as a joint venture in 2021 to create a tractor-mounted sprayer that precisely applies herbicides to weeds located by onboard cameras.

An artificial intelligence program analyzes images from the cameras in real time. It instructs nozzles to open when they are directly above a weed and stay closed when there are no weeds to spray. In field trials, the company showed that its sprayer used 70% less herbicide than a conventional broadcast sprayer. In April, equipment maker Agco announced that it would incorporate the technology in some of its tractors next year.

An herbicide sprayer applies a chemical to a weed.
Credit: Greeneye Technology
Greeneye Technology's sprayer uses artificial intelligence to identify weeds and then applies a targeted shot of herbicide to kill them.

Several start-ups are developing similar technologies. Greeneye Technology is already selling a sprayer that can be attached to a farmer’s tractor. CEO Nadav Bocher says the arm’s cameras can identify the species of a weed and send that information back to farmers. In the company’s first commercial season, customers reduced their use of in-season contact herbicides by 88%.

“That’s a game changer for farmers,” Bocher says. “It’s not only how much product you can save, but it’s also about the [herbicide] products you can use, which were not affordable prior to this technology because they were too expensive to broadcast across the entire field.”

Precision AI, which recently won the Cooperative Ventures Innovation Challenge at the World Agri-Tech Innovation Summit, is about to commercialize a drone that scours fields for weeds and records their precise locations on a digital map. Later, farmers load the data onto a tractor-mounted sprayer that sprays only the weeds identified on the map.

A fixed-wing drone flies over an agricultural field.
Credit: Precision AI
Precision AI uses a fixed-wing drone rather than one with only downward-facing rotors to avoid disturbing the air underneath the machine. That makes it easier to spray herbicides while flying.

The company is already testing the next generation of the technology: a drone that both spots weeds and automatically sprays them with a blast of herbicide from above. CEO Daniel McCann envisions a future in which farmers have a “hive” of drones that wake up once a week to scan the farm and spray any chemicals that are needed, with little human intervention.

“It sounds superfuturistic, but at the pace technology and AI is developing, I actually think it’s going to be shockingly closer than people think,” he says.

Until recently, this type of spot treatment simply wasn’t feasible, but advancements in cameras, computer chips, and artificial intelligence have made it possible.

Mottram, the analyst with Cambridge Consultants, says the first smart sprayers deployed on farms will be expensive, but prices will fall as the underlying technology improves. At the same time, Mottram says the cost of agricultural chemicals has been rising, strengthening the argument that this technology is a good return on investment. “Imaging technologies and hardware will keep getting cheaper,” he says.

Being more surgical and efficient with our nutrient applications means less of that impact on our water supply.
Steven Mirsky, research ecologist, US Department of Agriculture

Big business

If smart-spraying machines and systems to optimize the use of nutrients start spreading through the farm belt, they could chip away at the volume of chemicals needed to grow food. Combined with the impact of stricter regulations, the use of these tools has the potential to upend the crop protection industry’s long-standing business model of selling as much fertilizer and pesticide as possible.

“Chemical companies cannot follow the same path as they have been doing for the past 70 or 100 years: research, find a chemical, sell it, and keep selling it,” says Tim Appachanda, an agricultural analyst with Lux Research.

Rachel Rama, head of small molecules at Bayer Crop Science, says her company is starting to move toward a model in which farmers pay for the outcome, such as a field free of weeds, rather than a specific chemical. “You are not selling the liquid in the bottle anymore,” she says. “You are selling the results in the field.”

Like Bocher, Rama says applying lower volumes of herbicides more precisely could also open the door to products, such as biological herbicides or molecules with new modes of action, that are too expensive to use in a conventional, indiscriminate sprayer. “You can have a quite expensive product because at the end, the cost per hectare is going to be OK,” Rama says.

Other companies are taking the same approach. BASF, Corteva Agriscience, FMC, and Syngenta have all released software to help farmers use pesticides more efficiently. Bayer’s digital tools were used on more than 80 million hectares in 2022, but Mottram doubts that companies are generating a profit from such initiatives. “I don’t think anyone’s making huge dollar out of that today. But it’s definitely the route of travel,” he says.

Justin Gayliard, head of digital farming in North America for BASF, says the company has struggled to get farmers in North America to use its software. But the company is investing heavily in the program and still views it as a pillar for long-term growth.

“Our future is: How can we help agronomists use tools and technology to bring better decision-making to the farmer?” Gayliard says.

Fertilizer companies are experimenting with different business models as well. Nutrien is piloting a program that pays farmers to use less fertilizer. The company makes recommendations about how to reduce fertilizer use and measures how much those actions shrink each farmer’s carbon footprint. Nutrien hopes to sell the resulting carbon credits. The company “became the platform for trading carbon credits . . . which compensates for the lower purchase of inputs by farmers,” says Appachanda, who wrote a case study on the program.

Markus Braaten, market development director for digital agronomy at the fertilizer company Yara, says his company is increasingly focused on how much food its products help farmers grow rather than how much fertilizer it sells. But he says everyone in the industry is still calculating how to make money this way.

“Our current business model is not really designed for that. The entire agricultural value chain really isn’t designed for that,” he says. “We have to figure out how to create alignment in what we value across the value chain.”

Chemical companies cannot follow the same path as they have been doing for the past 70 or 100 years.
Tim Appachanda, agricultural analyst, Lux Research

Slow adoption

The companies developing technologies to use pesticides and fertilizers more efficiently are promising to make farming more sustainable and break agriculture’s dependence on expensive chemicals. But these tools won’t have any impact if farmers don’t use them.

Machines that apply fertilizer according to how much a certain area needs have been around since GPS became widely available, in the 1990s. After 3 decades, this method of fertilizer application is still used on only 28% of the corn grown in the US, according to a USDA report.

A satellite image of pivot-irrigated agricultural fields.
Credit: Planet Labs
Data gleaned from satellite images of fields, such as this one in Nebraska, can help farmers reduce their use of nitrogen fertilizer.

Many farmers say flashy equipment often fails to live up to lofty claims from marketing materials, and they can be skeptical that it will provide a good return on investment. That group includes Walz, who says the sensor he mounted on his tractor did reduce fertilizer costs, but it was difficult to use, and he wasn’t impressed with the manufacturer’s technical support.

With so many other tasks clamoring for his attention, it was hard to justify fiddling with a finicky piece of hardware, so he’s trying another approach. This year, he’s working with Sentinel Fertigation, which uses satellite imagery to recommend how much fertilizer to apply, which he’s hoping will be less work.

Even if it can occasionally be frustrating, Walz is hopeful that this kind of precise technology will help him apply even less fertilizer. “I feel like it has a place,” he says.


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