Dairy leaders have a goal of getting the industry to greenhouse-gas neutrality by 2050.

But in New York, programs focused on reducing dairy farms’ environmental footprint are already moving forward, with actual results being produced.

“Your processors, your retailers and, ultimately, your consumers are really driving this,” said Kirsten Workman, nutrient management and environmental sustainability specialist for Cornell Pro-Dairy, at the Northeast Dairy Management Conference in Syracuse, N.Y. “If we’re going to continue to sell dairy products, we need to understand what those environmental footprints are, because there will be other sectors of the dairy industry, and other parts of the food industry, who will be talking about this as well.”

Workman helps lead the Dairy Sustainability Project at Cornell, which is looking to quantify dairy farms’ environmental footprint through the collection of real farm data.

“Why are these tools important? Because you can’t manage without first making measurements,” she said.

One of those tools, the Whole Farm Nutrient Mass Balance tool, had 85 dairy farms participating in 2022. Quirine Ketterings, professor of animal science at Cornell and leader of the Nutrient Management Spear Program, said the concept involves taking a farm and drawing a boundary around it, and looking at what the farm is bringing in — feed, fertilizer, animals and bedding — and what the farm exports — milk, animals, crops and manure.

The 85 farms that had data analyzed by the tool in 2022 represent 21% of the state’s total milk production.

“That number has been growing,” Ketterings said, adding that in 2019, about 13% of the state’s milk was represented. “And it is a good mix of farms and milk production ranges. Our goal is to grow this to more than 50%.”

Some results from 2022:

The tool breaks down farm imports and exports by nutrient value — nitrogen, phosphorus and potassium. Those numbers then get divided by either tillable acres or by hundredweight of milk produced. Ketterings explained why it’s done this way:

“On a per-tillable-acre basis, it gives us a sense of how a farm is recycling the difference between what they bring in and what they export, on a land basis, so it is more of a sustainability indicator,” she said. “On the milk side, it is more of a production efficiency indicator — how much milk is produced from a farm from the amount of nutrients that’s imported.

“This is a very simplistic view of a farm but a very helpful view of a farm,” she added.

Based on work with 102 dairy farms, Ketterings said they came up with nutrient balance goals per-tillable acre and per hundredweight of milk produced.

The tool then produces graphs where a farmer can see their farm’s performance compared to past years and to other farms. The goal is for each farm to stay within the “green box” of nutrient efficiency.

“That green box is the sweet spot,” Ketterings explained. “That is where farms are able to achieve in such a way that they have a lower farm footprint and are efficiently producing milk.”

P is good, N needs work 

Data from 2022 show that farms are meeting the feasible balances for P, averaging 11 pounds an acre on the crop side and 0.07 pound per cwt milk.

On nitrogen, farmers are efficiently producing milk — 0.8 pound per cwt — but the per-acre average of 126 pounds is well above the threshold.

“If we look at the same set of farms but now we distribute them by animal density, farms with lesser animal density met the target rate for N but were actually less efficient in terms of producing milk, on a nitrogen basis. On the flip side, farms with higher animal density were way above on the N per acre but produced milk more efficiently,” Ketterings said.

Per-acre phosphorus balances didn’t change much per farm size, but farms with higher animal densities were more efficient on the milk side.

“They are becoming more efficient, but we simply don’t have the acres to recycle those nutrients. So, we have to look for other ways to address that,” she said.

Measuring carbon footprint

Another tool being used by researchers is the Cool Farm Tool, which calculates total farm emissions and emissions produced from milk production.

Forty-five dairy farms were analyzed in 2022. The tool breaks down emissions by source — like feed, grazing management, enteric emissions, manure, and fuel and energy use — and shows emissions by gas type, like methane, nitrous oxide and carbon dioxide.

Olivia Godber, research associate of animal science at Cornell, said the assessments showed most farms were well under 1 kilogram of carbon dioxide equivalent per kilogram of fat-and protein-corrected milk, but the range was between 0.63 and 2.17 kilograms.

How does this compare to other farms around the region and even nationally? Godber said she is not aware of a regional or national average calculated through the same tool, but other tools like the Food and Agriculture Organization’s Global Livestock Environmental Assessment Model, or GLEAM, for North American dairy show an average of 1.13 kilograms of carbon dioxide equivalent per kilogram of milk.

“We don’t want to just give you a number; we want to show you what progress has been made,” Godber said. “What we found is a farmer says, ‘Well, I’m going to do it,’ and they are already doing some really great practices on the farm. If they weren’t doing those practices, their footprint would be higher than it was. We want to show you that and how you got there.

“We have also developed an opportunity table so they can see what is driving the balance and what can be done, or is being done, to lower the balance. So, you get your number, and then it shows what can be achieved with different things done on the farm, like putting in a separator, going with 100% no-till or cover crops, other things.”

How to participate

Dairy farms that want to participate in the Cornell project will receive their farm nutrient balances and a comparison to all farms in the dataset. Farm identity is confidential.

To participate, farms can download the input sheet and instructions for submission. There is also a confidentiality agreement.

For more information, email Kirsten Workman at [email protected].