@gollum,
Id suggest you watch Ken Burns two prt documentary on the dust bowl. **** can happen in waves and, while one didn't cause the other, the dust bowl did affect the lives of about 3/4 million emigrees who lost their livelihoods due to the dust storms.
Ag practices that didn't consider erosion were the direct cause of the dust bowl, (that partnered with a brief and severe mini-desertification of the plains between 1933 and 37). During the mid to late 20's , soaring ag prices enabled farmers to invest in more mechanized "sod busting" practices which destroyed the subsoil zones and these practices removed the deep rooted grasses and turned the soils into loess deposits. Over the years, the main areas affected had lost as much as 75% of their topsoils and these are still not returned to original tilth. (For that reason newer practices rely heavily upon cover crops and deep rooted ryes and tall grasses, and also the use of No Till farming had been almost universal in the plains until the last 10 years(some return to deep tilling has been done and its a touchy condition with the recent droughts out there).
The dust bowl certainly didn't help reduce the unemployment but, absent its occurrence, we may have seen another few additional percents toward full employment during the Depression.