Cattlemen let their teeming herds graze the uncultivated land to a barren waste. Next came the droughts. The eroding soil, the barren land, and the blowing winds brought on the great dust bowl of the 1930’s that destroyed vast areas of farmland across five states of Midwestern America. The dust blew in clouds thousands of feet in the air, from horizon to horizon. It came through the cracks around the doors and windows. It piled in high drifts in the streets and fields, covering sheds, tractors, and farm equipment.

Millions of acres of farmland were destroyed by soil erosion. Precious topsoil, just one inch (2.5 cm) of which experts say can take several hundred years to build, was now, in a matter of a few months, gone with the water and the wind.

Increasing Losses of Topsoil

In America alone, the loss of soil is today an even greater crisis. “Of our current 421 million acres [170 million ha] of productive farmlands,” writes the National Wildlife magazine of February/​March 1985, “97 million acres [39 million ha] are eroding at more than twice the ‘tolerance’ level​—the level at which soil can be replaced naturally. Another 89 million acres [36 million ha] are eroding at one to two times that tolerance level. In all, nearly 40 percent of our farmlands are losing soil. In Iowa, some topsoils that were once a foot [30 cm] deep today are only six inches [15 cm]. One tenth of the rich wheat-growing Palouse region of eastern Washington has lost all of its topsoil. In parts of northern Missouri, half the topsoil is gone, and the land is still eroding at some five times the rate of replacement.”

Not all soil erosion is caused by blowing winds as was the case in the dust-bowl era and as is the case in much of Africa today. In the United States particularly, most of the erosion comes from rain runoff. According to the U.S. Department of Agriculture, reports for the year 1977 show that an estimated 6.4 billion tons of topsoil were washed away from farmlands, ranges, forests, and construction sites. The greatest portion of this topsoil loss was speeded up by human activities. “Off-road vehicles have in a few years scoured more soil off parts of California than nature will replace in 1,000 years,” said one authority.

Indeed, the farmers realized a bumper crop of grain production and with it came a greater farm income. But, alas, offsetting the handsome profits were the lamentations that went up from the same farmers when they realized that their farms were eroding away, by many tons to the acre. Published reports say that the United States is now losing topsoil at the rate of six billion tons a year.