Of cows and climate: CALS researchers leading effort to make dairy farms ‘greener’
On a subzero February day, Mark Powell stops his vehicle on the road a few miles outside Prairie du Sac. He’s been explaining that cows actually enjoy the polar weather—and as if to prove it, a frisky group in the barnyard across the road turns toward us and rushes the fence.
As a USDA soil scientist and CALS professor of soil science, Powell is focused on the ground beneath their hooves. A few years ago he led a survey of manure handling on Wisconsin dairy farms. He and his colleagues knew how much cows left behind—about 17 gallons a day—but had only educated guesses about the ultimate environmental impact of barnyard design. In open yards like this, says Powell, they found that 40 to 60 percent of the manure ends up uncollected. “It just stays there,” he says. In the decade since his survey, the manure challenge has only grown, both in Wisconsin and nationwide. Water quality has been the major concern, but air quality and climate change are gaining.
A few minutes later we turn into the 2,006-acre U.S. Dairy Forage Research Center farm, and the talking points all turn to plumbing. There’s an experimental field fitted to track how well nutrients from manure bond to the soil. Parallel to one barn are nine small yards with different surfaces, each monitored to measure gasses emitted and what washes out with the rainwater.
The manure pit is frozen over, but circumnavigating the complex—shared by CALS and the U.S. Department of Agriculture—we arrive at the southern terminus of the barns. Uncharacteristic ventilation ducts adorn the walls and roofline. Inside are four unique stalls that can contain up to four cows each. The manure trough is lined with trays so that each cow’s waste can be set aside for further experiments. When the cows return from the milking parlor, airtight curtains will drop, isolating each chamber.
And in a nearby room, sensors sample the air leaving each stall, recording the release of moisture, carbon dioxide, ammonia, nitrous oxide and methane. This data is at the heart of a $10 million, five-year USDA grant to examine climate change and dairying in the Great Lakes region.
In 2009, the dairy industry became the first major segment in the U.S. economy to volunteer a significant cut in its greenhouse gas production, vowing to eliminate 25 percent by 2020. Now in its second year, the project brings together industry, four USDA labs, dozens of researchers from eight universities, and even Milwaukee’s Vincent High School. Funded through the USDA’s Coordinated Agricultural Projects program, the working nickname is Dairy CAP—pronounced as if it were one word.
To hit that target requires a deliberate look ahead. “What is the climate going to look like in the future?” asks Matt Ruark, a CALS/UW-Extension professor of soil science and leader of the Dairy CAP endeavor. “What is the dairy industry going to look like 10, 20, 50 years from now? And are those two in conflict with each other?”
Sustainable dairying is the ultimate goal, and Molly Jahn, a CALS professor of genetics and agronomy, gives the dairy industry high marks for targeting greenhouse gases. “One thing we know, if you look back over the last 50 years, is that the conditions under which we are dairying are becoming more extreme,” explains Jahn, a co-leader on the grant. “Dairying has many benefits to landscapes. As the industry continues to grow, we want to continue to innovate with respect to productivity and quality—and in harmony with our natural resource base.”
Dairy CAP will provide not only academic results, but also tools and management practices. “We intend to provide dairy farmers with the resources to make sure they are managing their operations for maximum short-term benefit and for long-term success and resilience,” Jahn says.
Please continue reading this story, originally published in Summer 2014, on the Grow magazine website.