Climate-Friendly Farming Strategies Can Improve the Land and Generate Income for Farmers
A prairie strip filled with flowers and wild rye grass between soybean fields on Tim Smith's farm near Eagle Grove, Iowa, reduces greenhouse gases and stores carbon in the soil. The Washington Post / Getty Images
By Lisa Schulte Moore
Agriculture has not been a central part of U.S. climate policy in the past, even though climate change is altering weather patterns that farmers rely on. Now, however, President Biden has directed the U.S. Department of Agriculture (USDA) to develop a climate-smart agriculture and forestry strategy.
As a scientist focusing on agricultural land use and adviser to several farm organizations, I have the privilege of working alongside farmers who have figured out how to do just that. I am enthusiastic about farmer-led solutions to climate change. What does this look like?
USDA is committed to working with farmers and landowners to make climate smart practices work for you in a market-oriented way — a way that creates new streams of income, a cleaner energy future and a biobased manufacturing revolution. #EarthDay pic.twitter.com/PWHg9jGtYr— Secretary Tom Vilsack (@SecVilsack) April 22, 2021
Restore Strips of Native Plants Around Farm Fields
Plants remove carbon from the atmosphere as they grow, and soil can soak up carbon and store it. These abilities are key to climate solutions that crop farmers can readily deploy today.
Seeding narrow strips of land within and around crop fields with native plants is an effective and affordable way to make farming more climate-friendly. Iowa State University’s STRIPS Project has shown that this technique reduces erosion and nutrient loss from soil and supports birds and insects.
Prairie strips can reduce emissions of nitrous oxide, a greenhouse gas 298 times more potent than carbon dioxide. Nitrous oxide emissions vary widely across agricultural landscapes and over time, but the largest contributions are associated with poorly drained croplands.
Nitrous oxide forms under anaerobic conditions – environments without oxygen, such as low-lying wet areas of farm fields, where it is produced by soil microbes. The easiest way to keep it from forming is to avoid fertilizing these areas, which amounts to feeding the microbes.
Prairie strips help reduce nitrous oxide emissions by soaking up nitrogen fertilizer that runs off of adjacent cropland. They also can store carbon in soil in two ways: by trapping sediment moving down slopes, and by removing carbon dioxide from the atmosphere through photosynthesis and storing this carbon in plant roots and soil.
Turn Soggy Spots Into Wetlands
Since nitrous oxide emissions come mainly from wet zones, letting these areas remain as wetlands is another climate-smart strategy. Soggy areas tend to yield poorly in most years, and farmers rarely recoup their investment in cropping them. However, wetlands can be troublesome to farm around, which is why many farmers try to drain and farm through them.
But healthy wetlands also provide benefits: They sequester carbon, store and filter water and provide crucial habitat for mammals, birds, frogs and other organisms. The Agriculture Department’s new Climate-Smart Practice Incentive will support wetland restoration on agricultural lands.
Another USDA initiative, the Farmable Wetland Program, pays farmers to take previously farmed wetlands and buffer areas out of production for 10 or more years. Enrollment is currently capped at 1 million acres. A climate-smart agricultural policy could expand the program by removing the acreage cap and boosting incentive payments.
A prairie wetland in Minnesota, formerly part of a crop field (left) and restored to provide habitat for water birds (right). Shawn Papon/USFWS, CC BY
Promote Perennial Crops, Especially Grasses
All crops are not equal when it comes to mitigating climate change and conserving the environment. Perennials – including various types of grasses, shrubs and trees – provide more ecological benefits than annual crops like corn, wheat and soybeans. But they receive less government support.
Just like annual garden plants, annual crops must be replanted every year. Perennial crops live for multiple seasons, so raising them requires fewer climate-warming inputs, such as fertilizer and fuel to power tractors. These crops develop deep roots that soak up water in soggy spots and help stabilize soil on sloping land.
Many fruits, vegetables and forage crops are perennials. Examples include apples, alfalfa, grapes and asparagus. Researchers are working to develop perennial versions of grains, legumes and oilseeds such as sunflowers.
There are many opportunities to expand cultivation of perennial crops. Grasses and forbs – flowering plants with stems and leaves, such as bee balm – are less expensive to establish and grow than woody crops like willow, and offer farmers more management flexibility.
I direct a transdisciplinary team called C-CHANGE, funded by USDA, that is working with farmers to create and expand market-based value chains for perennial grasses. We are helping farmers plant mixtures of native perennial grasses and forbs to build soil health where it has been eroded and protect environmentally sensitive areas.
The grasses can ultimately be harvested and processed in biodigesters – devices that break down organic materials to produce energy – along with manure or food waste. This cycle will yield electricity or biomethane from renewable sources that can displace fossil-based energy sources on or off of farms. It also will produce liquid and solid materials that can be used as organic fertilizers, along with other valuable products.
Replacing fertilizer made from synthetic nitrogen is important for the climate because making it consumes enormous quantities of natural gas and releases methane into the atmosphere. Methane is another powerful greenhouse gas, 25 times more potent than carbon dioxide.
Biodigestion is widely used in Europe but underdeveloped in the U.S. We expect that the value chain we’re creating will embed it in a larger cycle that creates a market for protective perennial crops, reduces fossil fuel use and returns carbon to the soil.
The Agriculture Department’s Rural Energy for America Program provides grants and loans that can be used to support biodigester construction on farms. Expanding this program, which currently is funded at million yearly through 2022, and making biodigesters a priority, is another climate-friendly opportunity.
When I think of climate-smart agriculture, I picture farmlands with lots of perennial vegetation smartly integrated as prairie strips, wetlands and crops. Federal policies and programs that can make such landscapes a reality are already in place. With concerted efforts and investments, they could be expanded to achieve a pace and scale that will help address climate change.
Lisa Schulte Moore is a professor of Natural Resource Ecology and Management at Iowa State University.
Disclosure statement: Lisa Schulte Moore has received funding from the U.S. Department of Agriculture, Bia-Echo Foundation, Foundation for Food and Agriculture Research, Walton Family Foundation, McKnight Foundation, Iowa State University, Leopold Center for Sustainable Agriculture, USDA Forest Service, National Science Foundation, US Fish and Wildlife Service, 11th Hour Project, Bayer Crop Science, The Nature Conservancy, Syngenta, Iowa Soybean Association, Iowa Agriculture Water Alliance, DuPont-Pioneer, Renewable Energy Group, Iowa Department of Natural Resources, Iowa Ornithological Union, and Iowa Native Plant Society. She is on the boards of the Great Lakes Bioenergy Research Center, Practical Farmers of Iowa, Iowa Chapter of The Nature Conservancy, and Iowa Wildlife Federation, and advises Iowa Smart Agriculture.
Reposted with permission from The Conversation.