By Jacqueline Comito
Editor’s note: This is the fourth of five op-ed articles about various nutrient reduction methods outlined in the Iowa Nutrient Reduction Strategy, approved earlier this year. To read other articles in this series, visit the Iowa Learning Farms website: www.extension.iastate.edu/ilf/content/ilf-opinion-articles
The Iowa Nutrient Reduction Strategy advocates using multiple tools to improve Iowa’s water quality. Previous articles in this series have highlighted wetlands and cover crops — two important and highly beneficial tools for improving water quality and maintaining healthy Iowa farmland.
For producers looking for a comparatively easy conservation tool to implement or a tool to complement existing practices, buffers are attractive options.
Over the last few years, many producers have decided against planting buffers or even have converted existing buffers to row crops to take advantage of high grain prices. While the desire to maximize profits by planting valuable grain on all available land is understandable, the long-term economic and environmental benefits of employing conservation practices such as buffers likely will outweigh the short-term gains from high grain prices. Instead of viewing land productivity solely in terms of revenue, producers should consider land productivity as the sum of many functional benefits that buffers provide for one low cost.
Buffers are strips of permanent vegetation strategically placed in and around row crops. These buffer strips act as sponges during rain events, slowing down water flow and capturing sediment, nutrients and other pollutants. Like Iowa’s native prairie, the grasses used in buffer strips have deep roots that hold soil in place, and stiff stems that slow the flow of runoff water, helping water infiltrate down into the soil. As the water is slowed, the grass buffer strip captures sediment, nutrients and other pollutants.
According to the NRS, buffers can reduce nitrate loads by 91 percent and phosphorus loads by 58 percent. Because they are edge-of-field techniques, the NRS notes buffers do not directly affect row crop yields.
Like many of the tools proposed in the NRS, buffers are not only exceptionally effective at reducing nutrient loads and improving water quality, but they provide many additional environmental and economic benefits. Even small buffers can produce a number of multifunctional benefits disproportional to the amount of land used. As a result, even small land use changes by farmers can make a big difference.
As one of the most economical conservation best-management practices, buffers are quite a bargain for farmers. They require minimal land conversion and, after establishment, require little maintenance. According to Iowa State University researchers, it costs between $24 and $35 per year to convert one-tenth of every row crop acre from annual crop to prairie. While these costs may be higher when factoring in lost row-crop revenue, Conservation Reserve Program contracts often reduce buffer establishment costs by more than 80 percent. Therefore, farmers may only pay $3 to $5 annually for each row crop acre including a prairie buffer.
Buffers provide a number of environmental benefits. In addition to improving water quality, buffers also provide food and habitat for a number of beneficial animal species. These species include natural predators for crop pests, pollinators, songbirds and game animals. The Carroll Daily Times Herald recently reported pheasant hunters’ favorite hunting areas are being converted to row crops from CRP buffers.
Perennial buffer plants also can have agricultural uses. Farmers can use grassy buffer zones for livestock grazing or harvest grasses for hay. Additionally, perennial grasses and short rotation woody crops can be harvested for biomass feed stock. Initiatives such as the University of Iowa’s Biomass Partnership Project and similar industry projects that involve co-firing biomass with coal indicate that there is a growing market for perennial energy biomass sources in Iowa.
There’s no better place to start in farmland conservation than using buffers.
l Jacqueline Comito, an anthropologist and professor at Iowa State University, is the program manager for Iowa Learning Farms, a partnership among the Iowa Department of Agriculture and Land Stewardship, Iowa State University Extension and Outreach, Leopold Center for Sustainable Agriculture, Iowa Natural Resources Conservation Service, and Iowa Department of Natural Resources in cooperation with Conservation Districts of Iowa, the Iowa Farm Bureau and the Iowa Water Center. Comments: firstname.lastname@example.org