Greener Roadsides

Dust Bowl Lessons
quick fixes can have long term consequences

Bonnie L. Harper-Lore

The drought of the 1930's or "Dust Bowl" was the ecological equivalent of the collapse of the stock market, and its reverberations were felt across the country. As "Black Thursday" came to connote financial disaster, so the phrase the "dirty thirties" described the distress of the land, in particular the fragility of the topsoil. (Phoebe) As the blowing topsoils of the West landed on the steps of the Capitol in the East, the New Deal administration reacted in three ways:

1. Prohibited further homesteading by dedicating remaining land to controlled grazing,
2. Pulled out of production 11.3 million substandard acres, and
3. Began planting a transcontinental wind break.

The consequences of 65 years of grazing on public lands are well known. I suspect many of the 11.3 substandard acres were moved into production as irrigation technology improved. But a transcontinental windbreak....what were they thinking!

Prairie States Forestry Project

Black locust was widley planted during the dust bowl

They used the best information they had at the time; BUT planting a windbreak from Canada to Mexico that would keep soils blowing from the west in the West, seems ludicrous still.

Let's examine the border to border wind break idea. Instead of determining the causes of this remarkable erosion event, we attempted a band-aid solution of a symptom of poor farming practices. It was doomed from the start. The Prairie States Forestry Project included farmstead windbreaks, public land block plantings, and farm strip plantings. Although the plantings were considered a grand example of applied ecology; the plantings were oriented east-west rather than north-south. The plantings included many non-native species with seed imported far from other countries. The 1935 prototype included Chinese elm, Russian olive and caragana. All of these are now known weed problems. In addition, black locust became the most widely planted tree seed, moving it far from its original range in the Appalachian Mountains. Demand for black locust was so great its seed was imported from abroad! Subsequently, a seed industry developed in the Northwest that could handle orders of 100,000 pounds of black locust seeds. . We did the best we could with the information of the time; but did not forsee the consequences.

There were also positive consequences. Although the Forestry Project did not stop the loss of topsoil, shelterbelts did supply shade, beauty, less dust, and protection from cold. Shelterbelts around farmsteads continue to be used in this way. Although the windbreak itself did not stop soil loss, this report became the basis for silviculture in the Great Plains. The Project has been cited as "a remarkable example of applied ecology."

The demand for seeds and tree cuttings for this project generated businesses and jobs. Technology advances in propagation, refrigeration of stock, and field equipment improved. In the summer of 1934, many CCC camps were assigned to the Soil Conservation Service to carry out the work. But by 1936 Congress refused to continue the project's funding. For more details of this project note the references below.

(U.S. Forest Service, 1935)

Introduction of Kudzu....a "problem solver" from another land

Kudzu, planted as a problem solver, became a bigger problem.

Meanwhile in the southeast, between 1935 and 1941, some 73 million seedlings of Kudzu, an introduced Japanese vine, were planted to curb soil erosion on millions of acres of farm land. Before this massive planting, farmers had called it the porch vine because of the quick shade it was able to provide. That knowledge of the vine's potential impacts were not considered. With growth rates up to a foot per day, Kudzu has swallowed telephone poles, abandoned houses, trees and gullies. Just as the plains' shelterbelt was ineffective, the kudzu's performance was far too successful. Neither black locust-dominated shelterbelts or kudzu erosion control plantings have lessened erosion across the country. The solution still lies in thoughtful farm practices. Because of increased economic pressures on farmers, there is increased pressure to put more erosion-susceptible lands into production.

To this day, Kudzu persists throughout the southeast as its most invasive plant species. In the thirties we could not predict the consequences of a rapidly-growing, exotic vine. Science is now able to predict invasiveness. We also have learned from our past mistakes. Looking for problem-solving plants on our own continent has become ecologically smart. Unfortunately soil erosion continues to be a huge problem and we still do not address the causes well enough to prevent soil loss. Erosion controlling vegetation is only part of the solution. No-till farming is another. We have much to learn in the trend towards conservation farming begun in the 50's.

If another drought occurs, we will need to be aware of and use our best science thoughtfully. For once the winds become dusty, the people will call for solutions. Let's be sure we do not repeat the quick fixes used in the dirty thirties. (Cutler)

Curtis Prairie Restoration Project.....planting native grasses and forbs.

The Dust Bowl era, with its inarguable message of environmental devastation, had persuaded the Roosevelt administration of the urgency of land rehabilitation. (Stephanie Mills, 1995.) Consequently, after the drought one of Roosevelt's CCC camps was enlisted to work on one of the first examples of rehabilitation or restoration at the University of Wisconsin's Arboretum. With the help of the CCC, Ted Sperry, and Aldo Leopold, the John Curtis prairie was begun in 1934. Many of the lessons learned from this experiment apply to roadside revegetation efforts today.

Because the Curtis Prairie Restoration, believed to be the oldest in the world, is on University land, this project is likely the most closely monitored. What has been learned during the past decades is the most importance of:

1. weed removal during site preparation - to this day the weed species like sweet clover that were on the former agricultural site continue to persist. Elimination of invasive weeds during site preparation appears to be critical to success in the long run.
2. planting diversity - Unless a project is surrounded by a quality natural area (the Curtis Prairie is surrounded by an suburban environment), the only species you will find years later, are the ones you planted. Therefore, it is important to plant as much diversity as is available and that you can afford at the time. Adding diversity years later, has not been shown to be successful.
3. vegetation management - the Curtis Prairie is as successful as it is, because of continued maintenace. Management of existing weeds through pulling, cutting, spraying and burning have provided opportunities for learning, as well as one of the most successful prairie plantings done so far. Roadside plantings will need spot treatments to ward off noxious weeds.

Weaver Research Project

Prairie dropseed survives long term with a complex network of surface roots.

It was no accident that John Weaver was monitoring the prairies during the drought years. For forty years, he and his students monitored "that portion of the prairie that has 'resisted civilization' longest". What he learned during the dust bowl years has lessons for us today.

"Precipitation had been somewhat deficient and drought periods occurred in 1931 and 1933 when moisture was not available to the roots of plants in the surface foot of soil. This however, had little effect upon the (prairie) vegetation. Then came the summer of 1934 when drought was the greatest ever recorded in true prairie. This offered an exceptional opportunity to study the response of the native plants to extremely adverse water relations." (J.E.Weaver, 1954)

"No rain fell; clouds were rare.....The light was intense: the dust-filled, yellow, western sky in evening portended another day of drought. The hot southerly winds blew as from a desert drought that had bleached the green hilltops to patches of brown alternating with white, now crept down the slopes. The persistence of the grasses and forbs was remarkable. Only after days of wilting and rolling or folding of the leaves, weeks of battling the intense heat, high winds, and low humidities under the cloudless skies, did life finally retreat undergound to wait the advent of rain." By this point the fields of wheat, clover and corn were long gone. Weaver continued to examine 30 prairies in Iowa, Nebraska, and Kansas throughout the drought.

During the first year of drought more bare soils were exposed and the open spaces were filled by both introduced and native plant species. The invasive plants that increased under these conditions included: peppergrass, horseweed, and hairy chess. Some native forbs also acted as opportunists. Many-flowered aster, daisy fleabane, sleepy catchfly and Venus' looking-glass, wild onion, dogtooth violet, Carolina anemone, smooth goldenrod, sage, and yarrow outnumbered the grasses in many locations. Of the native grasses, Western wheatgrass was the greatest increaser. Buffalo grass and blue grama took advantage of the dieback of taller plants. The above-ground prairie looked different. But the below-surface system held on.

After seven years of drought, the dust storms finally stopped blowing. The Kentucky bluegrass found throughout the native pastures before the drought, had with rare exception, entirely disappeared west of the Missouri River. Little bluestem, buffalograss, June grass, along with tall dropseeed decreased in abundance. Side-oats grama, considered highly drought-resistant, survived the best of the native grasses. Plains muhly, a western drought-resistant grass, migrated eastward. Switchgrass, nodding wild-rye, and cordgrass held on in wet places, but were replaced by big bluestem and western wheatgrass in areas that dried. The landscape had noticably changed.

The forbs or wildflowers decreased sporadically. Deep rooted plants like prairie rose, leadplant, blazing star and false boneset held out the best. By 1940 most species of forbs had decreased greatly.

And why? Did they not go dormant or into survival mode? What was happening underground?

Infiltration of water was part of the problem. Increased bare soils led to less infiltration. Soil under native prairie grasses absorbed water more rapidly than soil covered by western wheatgrass. With less available water the prairie had been replaced by more xeric prairie plants.

The overall appearance of the tall grass prairie had changed to a mixed-grass prairie with shorter xeric plants replacing some tall species. Dormancy saved the diversity of the grassland. It took two to three years for the prairie to repair its cover. The bared soils were repopulated and recovered.

This stable prairie endured the disturbance caused by drought like it had done through other catastrophes of fire, flood and frost, just as it was adapted to do.

These drought tolerant plants have application to harsh roadside conditions. They are the low-growing, herbaceous, perennial ground cover that prevent soil erosion, accommodate wildlife, add seasonal variety, outcompete invasive weeds, and survive drought, floods, and more. Although most of the prairie ecosystem was historically located west of Ohio, every State has native grasslands in their natural heritage, and meadow remnants within their boundaries. Learn from these stable, drought-tolerant, cold hardy, self-reliant plant communities and especially protect any remnants that still exist on rights-of-way.

They will be useful to you over time and climate change.