In this epic dry year, we’ve heard a lot of “worst since the Dust Bowl” comparisons. I’ve been arguing that it’s a bogus comparison – one horribly dry year against a decadal scale phenomenon. But there’s a second reason, nicely captured by Kevin Welch today in the Amarillo Globe-News:
Farming practices imported from the Midwest contributed to the woes of the ’30s. Plows turned sod over, breaking it into fine particles. Mechanization turned small operations into farms covering square miles, Baumhardt said.
When it got dry and windy, the dust flew.
Some approaches developed by scientists involve not plowing under all crop residue after harvest, avoiding making the soil smooth or not plowing at all.
“Clods don’t blow,” Baumhardt said. “Wheat residue does essentially what tree rows do. It prevents the wind from getting the energy to move soil.”
The impact is less dust. Further, moisture is conserved because the soil isn’t disturbed as much so evaporation slows.
The Dust Bowl was part climate, part the result of farming practice. Farming practice was fixed.
“Fixed” seems overly bold.
Steve –
Benjamin Cook, who did some nice modeling work with Richard Seager on the effect of the dust itself and the modified farming practices between the ’30s and ’50s droughts, explained the fix and its effect in reducing dust in the comments here:
https://www.inkstain.net/fleck/?p=5579
“Worst since dustbowl” is meaningless to me, given the drought history and prehistory of the region, going back 1000 years.
“Fix” seems to me to imply something like a solution. Certainly the situation now is much better than during the dust bowl, but is it anywhere close to sustainable?
Taking Oklahoma as an example, I found this comment on an official state website:
“Conserving the soil is not an easy job. In 1982 wind and rain eroded over 113 million tons of soil in Oklahoma. Much of that soil ended up in our streams, rivers, and lakes. In 1997 the amount of soil lost in Oklahoma was 68 million tons. This reduction in soil loss is a direct result of conservation practices being implemented by many Oklahomans. Through education efforts, all Oklahomans can learn to appreciate and conserve our precious soil.”
So just dividing that 1997 number into OK’s area, we get a loss of 1,000 tons per square mile per year. That sounds like a lot.
It would have been nice to find a listing of annual soil erosion by state or even some more up-to-date figures for OK, but I couldn’t locate one.
See also this PNAS paper asserting that even the “fixed” sort of tillage practices can’t be anything close to sustainable. The author recommends no-till farming as something that can at least come close.
I’m sure things are better in wetter places, but this recent well-publicized report (article) on the state of soil erosion in Iowa (not a Dust Bowl state) seems to indicate a problem even there.
I live in Shawnee Oklahoma and my yard is turning to dust. No plowing needed. There is no moisture in the soil and any pressure at all and it disintegrates. This is bad, the next wind storm is going to be a dust storm. My grass is dead; there are no bugs; and few birds. Due to economic times I was going to buy some cattle, but my land cannot even support one goat. The worst avg temp during the dust bowl was 103.5 in JUL 1936, well it’s 112.5 right now.