Two years of drought in Oklahoma and Texas and a mounting toll of farm bankruptcies across the farm belt revived memories of the great dust bowl of the 1930’s, immortalised by John Steinbeck's 1939 epic novel The Grapes of Wrath.

In the dry heat of West Texas, mayors issued official proclamations asking the citizens to go to church and pray for rain. Old farmers recalled the hard years of the 1930’s, when the topsoil blew away so thickly that it blotted out the sun, and the roads disappeared under drifts of dirt. In the vast swath of Plains states that make up the US heartland, from the Texas scrub in the south through the old dust bowl of Oklahoma and Kansas, drought once again stalked the land.