Git Along Little Microbes
(A version of this article was published in the Stockman Grass Farmer, June, 2011)
Beef cattle belch out tons of methane. Some studies claim cows account for 18 percent of all greenhouse gas emissions. And it turns out that grass-fed cows belch more than their grain-fed cousins, a fact that gladdens the hearts of feedlot owners seeking a patch of moral high ground on which to plant a green flag.
Now along comes Bill McKibben to snatch the flag back for the grass-feeders. (“The Only Way to Have a Cow,” by Bill McKibben, Orion Magazine, March/April 2010.) How is it, he asks, that vast herds of wild ruminants never burped the skies full of methane in days of old? The answer, he claims, is methane-eating soil microbes: “Healthy soils sequester more of the gas in a day than cows supported by the same area will emit in a year.” The wild herds helped create healthy soils by massing together, chomping everything in sight, fertilizing the place and quickly moving on, pursued by wolves.
Pasture-based cow herds perform the same soil-building trick when they are crowded together and moved quickly, so the recovering grass can do its carbon sequestering, burst-of-growth thing. Old West trail bosses called it, “Head ‘em up and move ‘em out.” New-fangled ranchers call it “mob grazing.” Bovines on feedlots may belch less, but they also recycle less. Their mountains of manure and lakes of urine emit more methane and nitrogen into the air and waterways. Grass-feeders’ waste is quickly transformed into brunch for bacteria.
The soil created by this process is rich in microbial life: 4000 pounds of tiny, carbon-building, methane-eating bacteria per acre as opposed to only 400 pounds per acre in poor soils depleted by plowing and cropping and chemical fertilizers. Keeping the bugs well fed is as important as grazing the cows. Those of us who raise grass-fed beef, it turns out, need to be microbe ranchers.
The problem is that grass-fed beef take up more space and are more expensive to raise. Here the feedlot folks try to recapture the flag by claiming that they, not the grass-feeders, are the only ones who can efficiently supply a rapidly growing world population hungry for a taste of the meaty good life we enjoy.
Some environmentalists echo this view: “There are just too many people to feed, and, unfortunately, population is growing exponentially,” says Stewart David in his blog response to McKibben. “Where, exactly, is all of this ‘free range?’ How much of the planet would need to be deforested to make room for mass grazing? Do the math.”
The math, it turns out, isn’t so daunting. First it’s important to realize that feedlot beef already spend most of their lives on grass. It’s only the last three to six months before slaughter that they’re crowded together and stuffed full of corn. So the idea of fattening them on grass for 120 more days isn’t as outlandishly demanding of new pasture as it might seem.
Second, according to USDA, U.S. forest land has actually increased by some 17 million acres from 1987 to 2002. Twenty percent of forest land is also grazed—some 134 million acres—and when properly done, grazing helps keep the forest more biologically healthy and diverse. Some 62 million acres of crop lands are also grazed during part of the year. Take a drive across Kansas in the fall to see cattle munching on corn stubble.
Acres devoted solely to grazing have dwindled over the past 50 years, mostly because 297 million acres have been set aside for parks and wilderness. If anything is endangered, it’s grasslands, not forests. Even so, there are currently 783 million grazing acres available in the U.S. That comes to 8 acres per beef animal, not enough in the dry southwest but much more than needed in the great plains and south.
Third, mob grazing makes the grass grow faster. Some grass-feeders claim that for the price of some electric fencing, you can in effect nearly double the size of your ranch, forage wise. So if a wholesale shift from feedlot to grass-fed beef is unlikely, a sizeable shift could be easily accomplished without the need for more pasture land.
Possible, but is it likely? Although the economic math seems to point the other way, four trends may change the profit calculation. First, there is growing consumer demand for healthy food. When Cargill buys out Meyers Natural Beef, you know something’s afoot. Second is the increasing cost of grain-fed beef due to ethanol demand and more expensive fossil fuel inputs. Third is a shift toward greater corporate responsibility. At a 2010 “Global Conference on Sustainable Beef” convened by the World Wildlife Fund and MacDonalds, feedlot owners listened nervously as a dozen or so food behemoths pledged to make their beef supply chains more environmentally friendly.
Finally there are a growing number “ecosystem services” markets in many parts of the country that channel extra funds to ranchers who protect the water supply and capture greenhouse gases. Happily, such practices also increase grass yields and ranch profits.
So it’s a good time for us ranchers to saddle up and ride the range with our squinty-eyed gaze resolutely on the ground. Git along, little microbes.