Scientists help farmers create greener dairies
Sep 10, 2013 at 1:00 PM
Cows stand patiently in a tent-like chamber at a research farm in western Wisconsin, waiting for their breath to be tested. Outside, corrals have been set up with equipment to measure gas wafting from the ground. A nearby corn field contains tools that allow researchers to assess the effects of manure spread as fertilizer.
Scientists based at the University of Wisconsin-Madison have started a slew of studies to determine how dairy farms can reduce their greenhouse gas emissions. They will look at what animals eat, how their waste is handled and the effects on soil, water and air.
Their work is part of a government-sponsored effort to help farmers adapt to more extreme weather and reduce their impact on climate change. The studies also will support a dairy industry effort to make farms more environmentally friendly, profitable and attractive to consumers. The Innovation Center for U.S. Dairy is developing a computer program that will allow farmers to compare water consumption, energy use and greenhouse gas emissions from their farms to the national average and learn how improving their practices could help their bottom line.
"We like to say sustainability makes cents — c-e-n-t-s," said Erin Fitzgerald, the center's senior vice president for sustainability.
Environmentally speaking, the big issue for dairy farms for decades was manure.
Karl Klessig remembers state agents coming to his farm in 2002 and handcuffing him after an unexpected rain washed manure spread several days earlier into nearby Lake Michigan. Klessig was told that if his family didn't immediately till the manure into the ground, tearing up the grass that feeds their cows, he'd soon be in jail.
It was a big loss, but it "jump-started" their environmental awareness, Klessig said. The family welcomed researchers from UW-Madison and UW-Extension onto its property in Cleveland, about 70 miles north of Milwaukee, for tests that had some unexpected results.
For example, the family had been leaving its pastures untilled for up to a decade to allow the grass to build up density, feeding the cows and reducing erosion. But scientists found that also allowed phosphorus to accumulate in the top layer of soil. Klessig said his family has been able to reduce phosphorus by tilling pastures more often and growing corn, which uses phosphorus to grow.
They also learned the farm was losing hundreds of pounds of soil each year through its drainage system and wormholes were allowing manure to run into those pipes. It was nerve-racking to have researchers point out these problems, Klessig said.
"Sometimes you feel like you're on top of the table, and you only have underwear on," he said.
But the scientists also offered solutions, which Klessig said, "made us better farmers."
Studies like the ones done at Klessig's farm helped provide the basis for the computer program being developed by the Innovation Center. The tool will be bolstered by data from a $10 million project led by UW-Madison but including scientists, engineers and scholars from multiple universities.
It is one of four projects funded by the U.S. Department of Agriculture to help farmers in specific regions adapt to climate change while reducing their environmental impact, said Ray Knighton, national program leader for soil and air quality at USDA's National Institute of Food and Agriculture. The other projects involve the beef industry in the southern Great Plains and Southwest, wheat production in the Pacific Northwest and wood production in the Southeast.
The five-year dairy project focuses on a strip of the northern U.S. from New York to Wisconsin. It is climate-specific in part because things like temperature affect the amount of milk cows produce.
At the federally owned research farm in Prairie du Sac, scientists are looking at the impact made by relatively small changes. For example, as cows digest, they essentially burp out methane, a greenhouse gas. So, does changing the animal's diet make its breath less toxic?
They're also exploring possibilities like whether there's a relationship between the amount of milk a cow produces and how much methane it gives off. If so, it might be possible to one day tell farmers that cows with certain genes "will enhance your profits but also enhance the environment," said Mark Powell, the USDA soil scientist leading the team of researchers.
His and others' work will eventually be combined into what's called a life cycle assessment that tallies the environmental impact of the entire industry — from the corn grown to feed cows to trucks that deliver milk to grocers. Farmers and others in the dairy industry can then use that information to assess how their decisions add up.
"Engaging the dairy producers is the most important thing on this project," said lead researcher Matt Ruark, a UW-Madison assistant professor and extension soil scientist. "There is a public demand for milk. But cows don't just produce milk, they also produce manure and methane."
Klessig, whose family owns a cheese-making business along with its dairy farm, said farmers are eager for such information because their success depends on making good choices that they can explain to customers.
"We hear it from our customers at the creamery," he said. "It's not that we're organic or we're not organic. They actually want to understand what we're doing."