Could measuring greenhouse gases increase returns on Pennsylvania dairies?

This story by MIT Environmental Solutions Journalism Fellow Carolyn Beans was originally published in Lancaster Farming, where it appears with additional photos. It is part of a series of articles on climate-smart dairy.

 

Paul Mason of Mason’s Chrome View dairy in Nottingham, Pennsylvania, has high hopes for his new manure spreading tool.

At over 16 feet tall, the 360 Rain can maneuver through rows of corn, depositing liquid manure along the way.

Mason was initially drawn to the device as a way to deliver nutrients to his feed crops while also managing his manure supply.

“What do you do with manure?” Mason says. “When you’re a dairy farmer, that’s what you spend half your time thinking about.”

But Mason is now hoping that the tool may also help him earn more money by addressing another challenge: greenhouse gas emissions.

By spreading manure in season, rather than before planting, he expects the corn to take up the nitrogen compounds in the manure before the nutrient has the chance to convert to nitrous oxide, a greenhouse gas with more than 300 times the warming potential of carbon dioxide over a 100-year period.

Mason hopes to turn this reduction in greenhouse gases into carbon credits. But first, he has to show that the practice works.

Mason funded his 360 Rain purchase in part through a grant from a Penn State-led program called Climate-smart Agriculture that is profitable, Regenerative, Actionable, and Trustworthy.

This project, known as CARAT, began in 2022 with a $25 million grant through USDA’s Partnerships for Climate-Smart Commodities initiative. It aimed to use greenhouse gas sensors to systematically test how well climate-smart practices draw down emissions on dairies.

Presently, the future of CARAT is uncertain. In April, the USDA canceled the Partnerships for Climate-Smart Commodities, suggesting that grant recipients reapply to the agency’s new initiative, Advancing Markets for Producers.

Regardless of CARAT’s status, Penn State researchers still intend to monitor greenhouse gas emissions from Mason’s fields this growing season.

Many dairy practices are considered climate-smart because scientists have shown they reduce greenhouse gas emissions in university research facilities.

But exactly how well these practices play out on actual dairies is often hard to predict.

Currently, estimating emissions reductions on Pennsylvania dairies is especially challenging because much of the research on climate-smart practices has happened on larger farms, says Jayne Sebright, executive director of the Center for Dairy Excellence, a CARAT partner.

In addition to testing which climate-smart practices have the biggest impact, the CARAT initiative aimed to create new market opportunities for climate-smart practices that work well, through carbon markets or higher prices for climate-smart milk.

Exactly how much Mason stands to gain with his new manure spreading tool isn’t yet clear.

“A lot of it depends on what the Penn State guys find out with how much nitrous oxide this is actually saving,” he says. “The bigger that number, the more likely that I might be able to get something out of it.”

Every Farm Is Different

The most important sources of greenhouse gases on dairies are nitrous oxide emissions from fertilized fields, methane emissions from manure storage, and methane released with cow burps.

Estimating the amount of nitrous oxide and methane released from any individual dairy typically involves plugging data on cow numbers, manure storage, feed types and other farming practices into models that predict emissions.

Those models are only as good as the data that went into them, “and they’re really rudimentary in many ways,” says Joseph McFadden, a dairy cattle biologist at Cornell University, who was not involved with CARAT.

Part of the challenge is that these models are often built using data collected by researchers in controlled experimental settings. But environmental conditions and farming practices on dairies are highly variable.

McFadden, for example, studies feed additives given to cows in respiration chambers that measure the precise amount of methane emitted from the cows’ rumens.

These studies are important because they demonstrate how well practices reduce emissions.

But they can only provide estimates for how these technologies will work on actual farms. Many variables, from diet to cow breed, could affect performance.

“Everybody does things a little bit differently,” says McFadden. “And so it becomes really important to understand emissions on individual farms, and then look at how particular practices are going to be best suited for that particular farm.”

Measurements on Real Farms

CARAT researchers will visit Mason’s fields before and after manure treatments to take greenhouse gas measurements with sensors placed directly on the ground.

Mason will only use the 360 Rain on a portion of his property. On the rest, he’ll inject manure into fields just as he’s been doing for years. The CARAT team will then test whether the new approach reduces emissions more than his standard practice — and by how much.

“One of the big components of making this work as a climate commodity is knowing exactly how much greenhouse gases are reduced by a given practice,” says Penn State biological systems engineer Armen Kemanian, who led CARAT.

Kemanian had planned to use greenhouse gas sensors to closely monitor emissions on about a dozen Pennsylvania dairies over the next few years.

His team could then compare how well climate-smart practices work relative to business-as-usual approaches.

Sensors in barns, for example, could measure emissions when a farmer is using a particular feed additive and also after the farmer stops using that additive.

Where practical for the dairy, a farmer could apply a climate-smart practice on half of the fields one year, and then flip treatments to only apply it on the other half the next year.

Some farms would have also received permanent sensors mounted on 10-foot poles to collect greenhouse gas data 10 times per second and then send data back to the CARAT team every 20 minutes for two years.

These longer-term measurements would allow the researchers to study how well climate-smart practices perform as environmental variables like rainfall and temperature fluctuate over time.

Ultimately, they’d hoped to use the data from these sensors to improve their existing models of greenhouse gas production. The models would then help to better predict emissions on the more than 60 Pennsylvania dairies that had joined the CARAT program.

CARAT participant Brett Reinford of Reinford Farms in Mifflintown, Pennsylvania, is eager for more concrete data on his climate-smart practices.

“Without data, you’re not going to monetize the carbon side of things,” says Reinford. “We’re trying to be forward thinking, and I think there’s a huge opportunity in the carbon market once it settles down and quits becoming the Wild West.”

CARAT was not the only group planning to take greenhouse gas measurements on actual farms. Cornell’s Pro-Dairy team, for example, regularly measures emissions from manure produced by commercial herds, says McFadden.

But the existing data is still “very limited,” says McFadden, adding that efforts like CARAT could “help us provide better estimates for individual farms.”

Research Behind Climate-Smart

There’s reason to expect that the 360 Rain will reduce Mason’s greenhouse gas emissions, Kemanian says.

Currently, Mason injects manure into his fields, a practice that minimizes odor, limits nutrient runoff, and decreases the amount of nitrogen that is lost from the manure in the form of the gas ammonia.

The trouble, explains Kemanian, is that manure injection also creates nutrient-dense bands that can trigger microbes to proliferate. As these microbes feed, they suck the oxygen out of the soil, creating the low-oxygen conditions ideal for nitrate to convert to nitrous oxide.

With Mason’s new strategy, he’ll apply manure more regularly, but in smaller amounts, and while the crops are growing.

“Ideally, we are synchronizing the moment the crop will take the nitrogen with the moment we supply it,” Kemanian says. “We hope that’s a big advantage.”

As far as Kemanian knows, researchers have never directly tested whether spreading manure with the 360 Rain results in lower greenhouse gas production than manure injection.

But the CARAT program had also included a wide range of climate-smart projects that are proven to draw down emissions, even if the exact extent on actual farms isn’t always clear.

Reinford, for example, had planned to use CARAT funds to install 4,000 feet of piping that would carry liquid manure to a recently dug covered lagoon that will hold up to 8 million gallons of manure.

But with CARAT funding canceled, the pipes now sit in piles above ground.

“We have a bunch of pipe with no funding to pay for it and bury it. So we are not sure what to do yet,” Reinford says.

Reinford will still use his new covered lagoon, but he may have to transport the manure by truck rather than pipe — an expense he expects will cost him an additional $25,000 to $30,000 annually.

Currently, the farm’s liquid manure sits in a much smaller open lagoon. Even after passing through an anaerobic digester and liquid-solid separator, the liquid manure still contains nutrients that can feed methane-producing microbes.

Reinford expects that covering and flaring the new lagoon will significantly reduce the dairy’s greenhouse gas production. He’s planning to use a gas meter to track the methane he burns off in hopes of monetizing that reduction in the carbon market.

The additional manure storage space will also allow Reinford to more carefully time his manure applications — a benefit to the environment and his bottom line.

“We always had to spread manure when the pit was full,” Reinford says. “Now we’ll be able to give the crops the nutrients they need when they need it, not because we have to get it out in the fields. That’s going to be a huge savings for us from a fertilizer standpoint.”

Several CARAT participants had also expressed interest in using the feed additive 3-NOP, sold under the trade name Bovaer, Kemanian says.

Bovaer received Food and Drug Administration approval for use in dairy cattle in 2024. This synthetic compound blocks an enzyme in the cow’s rumen that’s required for the final stage of methane production.

Penn State researchers have been conducting studies on 3-NOP over the past decade. Their findings suggest this feed additive generally reduces the methane emitted by microbes in dairy cows’ rumens by about 30% without affecting milk production.

But Penn State researchers and others are still studying how variables like diet and length of application may affect results. Some studies suggest that 3-NOP gradually becomes a bit less effective with continued use over a cow’s lactation period.

“I suspect that the reduction will go back up to 30% (in the next lactation) and then slowly come back down,” McFadden says. “We don’t know the answer to that question.”

Overall, the data suggest that 3-NOP reduces methane emissions in university studies, Kemanian says. He hopes to see how it operates in the field.

Farmers Take the Lead

Kemanian believes that once dairy farmers have more data on where their greenhouse gas emissions are coming from, they’ll take the lead on developing the most innovative solutions.

Mason, he says, is an excellent example. It hadn’t occurred to Kemanian that the 360 Rain might help reduce nitrous oxide emissions until Mason presented the idea to the CARAT team.

“I always thought that that should be one of the goals of the project — to trigger that creativity,” Kemanian says.

Mason agrees that dairy farmers will develop practices that reduce greenhouse gas emissions, but not necessarily because they are aiming for climate-smart. Many of these practices that benefit the environment simply make farms more efficient, and dairy farmers are always working to improve efficiency, he says.

With his new manure spreading tool, Mason expects to spend less on fertilizer because more of the nitrogen in his manure will reach his crops in a form that the corn can efficiently take up.

“I don’t want to pay to put (nitrogen) in the air,” he says. “Who is that helping? Absolutely no one. Just the guy that’s selling me the nitrogen.”