With Sustainable Practices, New York Dairy Farms Achieve Lower Emissions

A number of New York dairy farms achieve low greenhouse gas emissions due to sustainable management practices like growing a high proportion of their own feed and making the most of manure, according to new research. The findings establish the first regional baseline for dairy farm emissions using data from real farms.

In the study, published March 3 in the Journal of Dairy Science, researchers collected data from 36 medium to large dairy farms in New York state from the 2022 calendar year. They found that emission intensities were lower per gallon of milk than national estimates and among the lowest reported across continents. Those lower emissions were due mainly to farmers growing their own high-quality feed and using manure rather than outside fertilizers and manure treatment systems to reduce methane.

"The key finding was that New York dairy farms produce a lot of feed on the farm, and that's a huge advantage for them," said first author Olivia Godber, research associate with the Cornell Nutrient Management Spear Program in the College of Agriculture and Life Sciences (CALS).

"They're doing a really good job of producing high quality crops with minimal inputs, and because those crops make good quality feeds, that is helping them get high milk yields which also lowers their emissions. This emphasis on good crop production is really helping in all the other aspects."

Senior author Quirine Ketterings, director of the Nutrient Management Spear Program and professor of nutrient management in agricultural systems (CALS), said the lower footprint—and the research to calculate it—is the result of the farmers' commitment to improving their emissions.

"What is pretty unique with this dataset is the fact that these farms are all willing to participate," Ketterings said. "There's a shared interest in learning, in knowing, an interest in figuring out the next steps."

Previous research about emissions from dairy farms was largely extrapolated from limited farm information or "representative" farms that may fail to capture important features of a farm, or diversity between farms. The study is the first to collect and analyze data that capture "whole farm" emissions from New York farms, which includes feed production, animal feeding, manure management and energy use.

Similar to other studies, the researchers found that methane from the cow directly was the biggest contributor to emissions, accounting for 45%, with feed production at 25%. Manure management practices accounted for 20% and had the widest variability between farms. Fuel, energy and transport made up the remaining 10%. Changes in manure management—incorporating strategies that capture methane, for example—offered the greatest opportunity for lowering emissions on some farms.

The participating farms ranged in size from around 300 to more than 6,000 cows, predominantly Holsteins; in 2022 the farms contributed 12% of the total milk produced in New York, which is the fifth largest milk-producing state. With data provided by farmers, researchers used the Cool Farm Tool, a global assessment tool developed by The Cool Farm Alliance, to calculate emissions. They then delivered individualized reports and analyses of emissions to the farmers.

The data could help farmers make decisions about the financial and environmental implications of incorporating practices that further reduce emissions. In addition to lowering the carbon footprint, sustainable practices can be associated with higher productivity and may give the farms greater access to incentives and new markets.

"If they take on a new practice on the farm, it's often not just to bring down their emissions—it's also going to increase crop yields, milk yields, reduce the amount of money they're spending on fertilizer," Godber said. "Many aim to be sustainable dairy farms, but they may also see a commercial advantage."

The reports also provided an estimate of emissions if farmers had not implemented regenerative or sustainable practices.

"Farms wanted to know their footprint. The co-ops and the supply chains were asking, but no one had the answer," Godber said. "So, we wanted to find out where farms are but also take a step back and look at where farms have come from, what their opportunities are in the future. Is it possible for dairy farms to reach net zero? We need a starting point to understand that."