By Ryan C. Christiansen
As you drive by on highways you see them between farmers’ fields: uprooted trees and bushes, bare limbs akimbo and bleaching in the sun, all piled up in a straight line.
If you weren’t from around here, you might wonder why the farmers didn’t get rid of those trees a long time ago. You might not even realize that they’d been planted there deliberately in the first place and for a good reason.
Very few people alive today will remember The Dirty Thirties, also called The Dust Bowl of the 1930s, when dust storms damaged the prairies of the United States. Decades of farming without heed to soil conservation practices and a severe drought led the soil to dry up, turn to dust, and blow away in dark clouds dubbed “black blizzards,” forcing hundreds of thousands of prairie dwellers to leave their homes. In response, President Franklin D. Roosevelt issued an executive order in 1935 that windbreaks should be planted in the Great Plains states of North Dakota, South Dakota, Kansas, Oklahoma, and Texas. During the next seven years, the U.S. Forest Service, the Works Progress Administration, and the Civilian Conservation Corps worked together with farmers to complete the Prairie States Forestry Project. They planted more than 18,000 miles of windbreaks. These “shelterbelts” not only protected fields from the wind, but also created microclimates where soil moisture, air temperature, soil temperature, and relative humidity increased, producing higher yields for farmers.
Shelterbelts from the last century have depleted, however, and instead of restoring them, farmers are removing them to use the acreage for crops instead of wind protection. “If you drive across the state of North Dakota, you can see big piles of trees where farmers are taking them out. It’s not something we like to see,” said Brian Johnston, CEO for the North Dakota Association of Soil Conservation Districts, which owns and operates the Lincoln-Oakes Nursery in Bismarck and Oakes, N.D. The nursery started during the original Shelterbelt Project of the 1930s and continues to provide trees to soil conservation projects throughout North Dakota. “It’s our purpose for being,” Johnston said of the nursery, “but it’s definitely decreasing.”
So, as farmers begin to dismantle the old shelterbelts, might we see a new dust bowl on the prairie? Why in the world are farmers getting rid of windbreaks instead of restoring them or planting more?
The answer is complicated, of course, but one of the main factors is the widespread adoption of no-till farming, which involves growing crops without disturbing soil through tillage. Farmers now leave behind more water and more organic matter than they used to, which decreases soil erosion and reduces labor, machinery, fuel, and irrigation costs. Farmers also experience higher yields when they practice no-till.
“Where no-till is used, it makes a huge difference in the amount of wind erosion that takes place and the amount of soil that is picked up by the wind,” said Eric Anderson, an area resource conservationist for the USDA’s Natural Resources Conservation Service in Thief River Falls, Minn. “Thirty years ago,” he said, “everyone was using the moldboard plough, but that’s a thing of the past. Agriculture has made great strides to reduce tillage, but there are still some improvements to be made.” Anderson said in the Red River Valley, where the soil tends to warm up more slowly in spring, farmers might prefer to use the strip-till soil conservation practice over no-till. With strip-till, a farmer disturbs only several inches of soil in each seed row, exposing that soil to the sun. “You need to have a certain amount of exposed soil to get it warmed up and to get the crop growing,” Anderson said. “Strip-till will allow for that.”
With no-till and strip-till, windbreaks might not be as necessary as they once were, but shelterbelts offer benefits that go beyond soil conservation. Windbreaks can protect crops from wind-related damage, which can lead to further injury from pests and disease. Shelterbelts also protect humans by containing airborne dust, agricultural chemicals, and odors to the fields.
And even when the wind isn’t blowing, windbreaks enhance habitat for wildlife, especially double-row windbreaks, Anderson said, because they can be used by hunters and wildlife species alike as they travel the lanes or for cover.
Through the NRCS, the USDA offers financial and technical assistance to landowners for restoring windbreaks or putting in new shelterbelts. However, the benefits that windbreaks provide and the incentives available to keep them in place may not be enough. The temptation to remove shelterbelts and to replace them with row crop acreage is growing.
For one thing, windbreaks get in the way. Today’s farming equipment is much bigger than it used to be and with today’s implements, you can plant and fertilize more rows in one pass. “It’s more of an inconvenience now to have to work around a tree row than it used to be,” Anderson said. “As you travel down a field, if you have a windbreak, you might not be able to line up next to it and make a full pass; it goofs up your efficiency. Not having windbreaks makes for a more efficient operation, because it lowers the total cost for fuel and fertilizer. Double applications cost you money.”
Another reason farmers are removing windbreaks is because cropland is becoming too valuable to keep it in trees. “I can say conservatively that we’ve seen land values triple throughout much of the Red River Valley,” Anderson said. And commodity prices are up, too. “Fifteen to 20 feet on either side of the shelter belt is where the root system sucks nutrients out of the soil,” Johnston said. “It becomes a question of dollars-per-acre.”
Even so, some farmers do continue to restore or put in new shelter belts. “There are still a lot of benefits to having windbreaks,” Johnston said, “wildlife being the main reason.” And soil erosion continues to be a general concern. “There are still areas out there where windbreaks are a very good option,” Anderson said. “We need to find a way to take advantage of what trees have to offer.”
Photo courtesy of the Historical and Cultural Society of Clay County