When it comes to making the ag landscape healthier, how much is enough?
One day in 2007, a farmer walked into Paul Wymar’s office in Montevideo, Minn., not far from where the Chippewa River drains into the Minnesota River. He had a question for Wymar, who at the time was a scientist for the Chippewa River Watershed Project: how much of the land in the single biggest tributary of the Minnesota basin would need to be converted from annual row crops like corn, soybeans and sugar beets to a year-round ground cover regime before water quality would improve significantly?
The answer was 10 percent. After poring over a dozen years worth of water monitoring data, Wymar was able to show that in the parts of the Chippewa River watershed where at least 34 percent of the land was covered in plants year-round, water quality was good enough to meet state standards for clarity and chemical contamination. As it turns out, on average 24 percent of the 1.3 million-acre watershed is covered in grass, hay, trees and other perennials, so adding another 10 percent overall would do the trick (extensive watershed modeling done in 2014 verified that figure).
A simple answer, but one that means little unless another very important question is dealt with: which 10 percent? The answer to that lies in an area of farmland conservation that works to identify which parts of a watershed would benefit the most from, for example, having more deep-rooted perennial grasses growing in place of annual row crops. Called “targeted” or “precision” conservation, it relies on combining high-tech satellite imagery with low-tech kitchen table conversations to identify those spots that provide the most ecological bang for the buck. Such a strategy is being utilized in the Chippewa River watershed today by the Land Stewardship Project and various other partners. If it’s successful, it could serve as a model for providing farmers and other local residents the information and tools needed to protect water quality in a manner that is economically viable.
Punching Above its Weight
A study published in the February 2015 issue of the Journal of the American Water Resources Association outlined the limitations of traditional farmland conservation strategies, which, through such agencies as the USDA’s Natural Resources Conservation Service, often consist of getting practices applied to as many acres as possible, regardless of the ultimate impact. The study looked at conservation practices in Minnesota, Wisconsin, Iowa, Illinois and other states that make up the Upper Mississippi River-Ohio River Basin—the traditional Corn Belt—and found that applying water-friendly techniques such as cover cropping and reduced fertilizer applications across the entire region won’t do enough to reach water quality goals.
But by targeting areas that are particularly vulnerable to runoff with a mix of intense conservation techniques—everything from utilizing wood chip bioreactors near tile drainage lines to restoring wetlands—nitrogen runoff in the Upper Mississippi-Ohio River Basin could be reduced by 45 percent. That percentage is the threshold the Environmental Protection Agency has set for reducing the size of the “dead zone,” an area in the Gulf of Mexico that’s about the size of Connecticut and Rhode Island combined. Nitrogen fertilizer and other nutrients escaping Midwestern farm fields are supercharging algal growth in the dead zone, sparking a chain reaction that reduces oxygen levels to the point where virtually no marine life can survive. That 45 percent reduction could be attained by converting as little as 1 percent of the basin’s cropland to land uses that filter and hold nutrients, concluded the study.
Such results could have a major impact on agricultural conservation policy. Over the years, conservation programs have been used to disperse payments to farmers and other landowners without actually looking at the actual impacts on the land, says Matt Liebman, an Iowa State University agronomist who occupies the Wallace Chair for Sustainable Agriculture.
“We often pay for practices rather than outcomes,” he says. “It’s not the best use of society’s dollars. It’s clear that random acts of conservation are a waste of money.”
Despite decades of spreading conservation dollars across wide expanses of the landscape in the Midwest, the Gulf dead zone continues growing and nutrient pollution overall gets worse. The Minnesota Pollution Control Agency has found that nitrogen contamination is so bad in the southern half of the Gopher State that 27 percent of lakes and rivers are too polluted to be used for drinking water. Over 50,000 water samples and 35 years of monitoring data show that 70 percent of that nitrogen contamination in Minnesota is coming from crop fields.
That’s why conservationists are increasingly looking at targeted conservation. Liebman knows personally how effective it can be to utilize a well-placed practice that has an outsized positive impact on the landscape. On a recent summer day he stood next to a strip of native prairie on the side of a hill otherwise planted to soybeans in central Iowa. The prairie “strips” were established at points in the sloping field where runoff was at its most intense, and thus was doing the most environmental damage. What he and other researchers have found is that planting a row-cropped field to just 10 percent of native prairie can reduce by as much as 90 to 95 percent the soil and fertilizer runoff that escapes the field.
Those results, which far exceeded expectations, have prompted over two-dozen farmers around Iowa to plant their own prairie strips. And now that the innovation has left the test plot, farmers are putting their own creative spin on making the strips more effective, as well as economically viable. For example, one farmer in southwestern Iowa is grazing cattle on the prairie strips, providing cheap forage for his operation while reducing runoff.
Liebman sees prairie strips as one of many targeted innovations that can help farms keep water cleaner while providing wildlife habitat and other ecosystem services such as carbon sequestration. Grassed buffers along waterways, controlled drainage systems that allow water to percolate down into the soil profile gradually, and reconstructed wetlands are just some of the innovations now available.
“We have a portfolio of conservation practices,” says Liebman.
But he cautions that while it’s easy to get excited about such practices, they are only effective if they are targeted at environmental hotspots and become integrated into agricultural operations. That requires working with the land, and farmers, on an intense, local basis, something the Chippewa 10% Project is doing.
Not an Rx
Since it was launched in 2010, the goal of the Chippewa 10% Project has been to dovetail ecological health with the economic and practical needs of farmers and other landowners in the watershed. An initiative of the Chippewa River Watershed Project and the Land Stewardship Project, which are working with various other groups and agencies, Chippewa 10% is a model for making sure conservation practices produce real benefits. Such an approach is needed to grapple with one of the most vexing non-point water pollution issues out there: how to reduce the amount of nitrogen fertilizer leaving farm fields, causing problems all the way to the Gulf’s dead zone.
Corn has a voracious appetite for nitrogen, and keeping this nutrient from becoming a pollutant is particularly tricky because of its ability to leach through the soil profile and find its way into water via often mysterious, unseen avenues. Traditional conservation efforts such as terraced hillsides, which have been effective at reducing soil erosion, don’t always work when it comes to nitrogen runoff.
To get a handle on nitrogen pollution, as well as erosion and other water quality problems, the Chippewa 10% Project is utilizing some of the most sophisticated land and water mapping technology available. Geographical information systems (GIS) use satellite data and a remote sensing technique that combines radar and light, called LiDAR, to provide a 3-D map of watersheds, showing everything from drainage patterns in fields and where excessive water runoff is most likely to occur, to where certain conservation practices and structures would produce the most benefit.
“Sometimes thinking about the whole watershed may be too big,” says Steve Ewest, a GIS specialist with LSP. “We’re trying to bring this information to the field level. It’s ground-truthing.”
As he says this, he flashes through a series of colorful watershed maps from the Chippewa that show things like the “stream power index,” which measures the erosive power of overland flow related to such factors as slope and how drainage from upstream feeds into the system. Using data gathered from projects that study the effectiveness of different conservation practices, Ewest can plug in how various land uses—cover cropping, grazing, diverse rotations—could impact those patterns positively. On this particular day, he’s preparing these graphics for an upcoming meeting with a group of cover-cropping farmers in the watershed to get feedback on what kinds of maps would be the most useful for them when making planting decisions.
“We’re trying to get away from prescriptive conservation practices and more toward helping farmers see options,” says Ewest.
That’s an important point when it comes to applying targeted conservation in the field: to be effective, it has to take into consideration the human element of a watershed. The authors of the February 2015 Journal of the American Water Resources Association paper utilized highly sophisticated watershed modeling science to reach their conclusions. But it’s telling that the paper also points out that farms are connected by water and nutrient flows, and not all pieces of land are created equal when it comes to the impact they can have on those flows. As a result, “cooperative conservation” between landowners in a watershed is key. “The watershed approach is critically dependent on successfully engaging landowners and local communities in decisions about the future of the place they call home,” wrote the scientists.
Robin Moore, who coordinates the 10% Project, says that in the Chippewa watershed sophisticated watershed maps are helpful in figuring out where to focus efforts, but in order to develop the most effective targets possible, people must be integrated into the implementation of “3D visualizations” and “stream power indexes.” Targeting a highly erosive field with a rotational grazing system or no-till cropping may work on paper, but what if the landowner doesn’t have livestock or conservation tillage equipment?
That’s why over the past few years Moore and LSP organizer Andy Marcum have made numerous cold calls to landowners, agencies and natural resource experts in the Chippewa watershed, searching for issues they can work together on, as well as deciphering some of the major challenges to adopting innovative practices. Through follow-up interviews and outreach, they have found, for example, that cattle farmers in the upper reaches of the watershed are finding it hard to get access to enough grazing, while farmers in the lower reaches, where row crops dominate, find wet, cold soils get in the way of utilizing practices such as no-till cropping.
As a result, Moore and Marcum have developed farmer networks focused on cover cropping, grazing, soil-health monitoring and fertilizer management. One network engages women landowners, an increasingly important rural group. Field days and networking have helped farmers gain access to cost-share funds to establish, for example, cover cropping and grazing systems.
“You have to put your resources into talking to everybody about what needs to be done,” says Moore. “Without that you can’t create a target to hit in the first place.”
Brian DeVore is the editor of the Land Stewardship Letter.