I’ve come accross two ideas as to what caused the dust bowl. Which is correct, or are they both? Murray Rothbard states in For A New Liberty on p. 312:
Another unhappy consequence of the American government’s failure to allow private property in a resource was the destruction of the Western grasslands in the late nineteenth century. Every viewer of “Western” movies is familiar with the mystique of the “open range” and the often violent “wars” among cattlemen, sheepmen, and farmers over parcels of ranch land. The “open range” was the failure of the federal government to apply the policy of homesteading to the changed conditions of the drier climate west of the Mississippi.
In the East, the 160 acres granted free to homesteading farmers on government land constituted a viable technological unit for farming in a wetter climate. But in the dry climate of the West, no successful cattle or sheep ranch could be organized on a mere 160 acres. But the federal government refused to expand the 160-acre unit to allow the “homesteading” of larger cattle ranches. Hence, the “open range,” on which private cattle and sheep owners were able to roam unchecked on government-owned pasture land. But this meant that no one owned the pasture, the land itself; it was therefore to the economic advantage of every cattle or sheep owner to graze the land and use up the grass as quickly as possible, otherwise the grass would be grazed by some other sheep or cattle owner.
The result of this tragically shortsighted refusal to allow private property in grazing land itself was an overgrazing of the land, the ruining of the grassland by grazing too early in the season, and the failure of anyone to restore or replant the grass—anyone who bothered to restore the grass would have had to look on helplessly while someone else grazed his cattle or sheep. Hence the overgrazing of the West, and the onset of the “dust bowl.” Hence also the illegal attempts by numerous cattle men, farmers, and sheepmen to take the law into their own hands and fence off the land into private property—and the range wars that often followed.
Yet Doug French states (http://www.lewrockwell.com/french/french84.html):
The First World War then set off a series of events that would lead to disaster. The dry-land farmers had enjoyed prosperity, working the land and growing wheat with the benefit of new machinery that made them wondrously productive. Then the Turkish navy kept Russian wheat from making its way to Europe and the federal government told farmers to produce more wheat to win the war. And produce they did; from 1917 to 1919, the number of acres put into wheat production increased 70 percent. And why not: the government guaranteed a price of $2 per bushel.
But when the war ended, the price collapsed and there was no one to buy the mountains of grain left rotting in the sun. The debts incurred to buy equipment and property still had to be paid, so farmers continued to plow up the grassland in hopes that the price of wheat would rebound. By 1931, 33 million acres in the Great Plains had been plowed. But farmers could only sell the wheat for half what it cost to produce the golden grain, if they could find buyers at all. And then the winds came.
The black blizzards began in earnest in 1932 and would continue through the end of the decade. These storms would carry enough static electricity that people would avoid shaking hands because the shock would flatten a person. With no rain and temperatures exceeding more than 110 degrees for days on end, more and more bugs appeared. Grasshoppers swarmed over fields; centipedes by the bucketful infested houses, along with Black Widow spiders and Tarantulas. Rabbits multiplied while the people choked from the dust.