About eroded soils: our contemporary deserts
This quote of The Grapes of Wrath (1939) by John Steinbeck refers to the role of mechanisation in this terrible period of dust storms that distressed the United States Great Plains in the 1930s: the “Dust Bowl”.
With the beginning of intensive farming by hopeful migrants in the drylands of the Great Plains, pastures covered by native grasses capable of keeping soils moist were gradually replaced by corn & wheat. Added with extensive deep plowing made possible by tractors, 1930s droughts turned the precious soil of uncovered fallow fields into dust. It was then only a matter of time before wind blew it away in apocalyptic black blizzards that buried houses and caused “Dust Pneumonias” among farmers children, forcing 3.5 million people to migrate.
In less than 50 years, intensive agricultural practices and misunderstanding of ecology led to a desertification process caused by erosion, similar but faster than what The Fertile Crescent soils suffered centuries ago (see our article on carbon).
To prevent erosion and restore the lands, Roosevelt government established the Soil Erosion Service in 1933, that led to New Deal’s government subsidies shared by landowners & laborers. Despite subsidies, farmers failed to switch to other types of activities more suitable for eroded soils, such as growing livestock or appropriate crops. Indeed, credit wasn’t available because of heavy bankruptcy in the Plains during the Great Depression.
In the 1960s during the Green Revolution, land productivity was eventually increased by irrigation, synthetic pesticides & mineral fertilisers in the most unsustainable way, showing that not much was learnt from the Dust Bowl episode.