I just finished the Worst Hard Time by Timothy Egan, published back in 2006, about the Dust Bowl.
On several levels, I had a deep connection to the themes in the book. I can recall stories from both my mother's and father's mothers (my grandmothers) about growing up in the dust bowl era in and around the regions Egan discusses in his book. As a child I can remember going with my dad to a nearby shelter-belt (which I presume was part of Roosevelt's plan to avert the dust bowl, at least according to Egan) to chop wood for our fireplace.
Egan repetitively makes the argument (with a tedium that bored me at times) that the the great plains should have never been plowed. It should, in his assessment, have been left in natural grasses. The dust bowl itself, in Egan's account, was a result of man's hubris that nature could be tamed.
Egan's account paints both a cynical and overly-optimistic view of government. On the one hand, the government partially caused the great plow up (citing mainly from government reports at the time):
"Mistaken public policies have been largely responsible for the situation," the report proclaimed. Specifically, "a mistaken homesteading policy, the stimulation of war time demands which led to over cropping and over grazing, and encouragement of a system of agriculture which could not be both permanent and prosperous."
...
"The settlers lacked both the knowledge and the incentive necessary to avoid these mistakes. They were misled by those who should have been their natural guides. The Federal homestead policy, which kept land allotments low and the requirement that a portion of each should be plowed, it now seems to have caused immeasurable harm. The Homestead Act of 1862, limiting individual holding to 160 acres, was on the western plains almost an obligatory act of poverty."
On the other hand, Egan suggests the government-man Hugh Bennett's plans of contour plowing and grass-reseeding along with Roosevelt's plan of shelter-belts and farm price support policies saved the day.
I'm not so sure. It is tough to separate compelling journalistic story from data-driven explanations. My own sense coming into the book is that much of the land I grew up around, which falls within the area Egan draws around the dust bowl era, is as plowed up as it ever has been. The data would seem to support that too. I dug up USDA data on the number of acres planted to wheat in Cimarron Co, OK (which is where Boise City is located - one of the spots featured in Egan's book).
While there was indeed a big plow-up just prior to the dust bowl (which occurred in the 1930s), we can see that we've had just as much land in wheat production in the late 1940s and almost as much in the late 1970s. To the extent that the same is true in other regions and with other crops, it doesn't seem that replanting back to grass is THE explanation (although it might have played some role on more erodible lands in other areas).
A better question.
In the past several years, we've had severe droughts in the great plains similar to the one in the 1930's. Why no repeat of the dust bowl?
Egan asks a similar question, and he points mainly to the aforementioned government policies. He also gives the impression in the end that big corporate agribusinesses have taken over this land (which is largely false; there are fewer farmers today and those farmers are indeed bigger, but they are family farms; moreover his statements on this topic are somewhat ironic given the aforementioned quote that larger farm sizes were needed to avoid poverty). As indicated in the graph above, I don't think the full answer can be that the land has reverted back to idyllic native grasses.
My sense is that it is mainly a result of two factors: better farming technologies/practices and irrigation. To be fair, Egan points to these as potential answers too. Many of the people who moved out to farm the great plains had no prior farming experience. Its no wonder they adopted some practices that were doomed for failure (I'm sure I'd have done the same thing; I'd hate to think what would happen if I were forced to try to make a living at farming today!) Knowledge and experience matter. And sometimes it takes really bad consequences to teach us to do things differently.
On the issue of irrigation, there was an interesting paper (earlier ungated version here) that recently appeared in the American Economic Journal: Applied Economics by Richard Hornbeck and Pinar Keskin. They write:
Agriculture on the American Plains has been constrained historically by water scarcity. Post-WWII technologies enabled farmers over the Ogallala aquifer to extract groundwater for large-scale irrigation. Comparing counties over the Ogallala with nearby similar counties, groundwater access increased agricultural land values and initially reduced the impact of droughts. Over time, land use adjusted toward water intensive crops and drought sensitivity increased. Viewed differently, farmers in nearby water-scarce areas maintained lower value drought-resistant practices that fully mitigate naturally higher drought sensitivity. The evolving impact of the Ogallala illustrates the importance of water for agricultural production, but also the large scope for agricultural adaptation to groundwater and drought.
Ultimately, we may never know the ultimate causes and consequences of the dust bowl. It seemed to arise from a unique combination of an adverse turn in weather/climate, poor farming practices, poor economic conditions (the Dust bowl and the Great Depression occurred at the same time - how's that for bad luck!), unscrupulous land salesmen, and bad government policies. The consequences, it seems, were long lasting.
Hornbeck has another 2012 paper (earlier ungated version) specifically on the dust bowl in the American Economic Review related to how long the impacts of the dust bowl were felt. He wrote:
The 1930s American Dust Bowl imposed substantial agricultural costs in more eroded Plains counties, relative to less-eroded Plains counties. From 1930 to 1940,
more-eroded counties experienced large and permanent relative declines in agricultural land values: the per acre value of farmland declined by 30 percent in high erosion counties and declined by 17 percent in medium-erosion counties, relative to changes in low-erosion counties.
and
The Dust Bowl provides a detailed context in which to examine economic adjustment to a permanent change in environmental conditions. The Great Depression may have slowed adjustment by limiting access to capital or outside employment opportunities. Agricultural adjustment continued to be slow, however, through the 1940s and 1950s. Further research on historical shocks may help understand what conditions facilitate long-run economic adjustment. The experience of the American Dust Bowl highlights that agricultural costs from environmental destruction need not be mitigated mostly by agricultural adjustments, and that economic adjustment may require a substantial relative decline in population.