We've all heard of the phrase, "Salt of the earth", going back to biblical times. Living in a desert, though, perhaps the phrase isn't entirely benign. Originally meant as praise, the arid-land twist could well turn it into opprobrium. After all, in our irrigation-based agricultural economy, salt is about the last thing that we want—but we get it, wanted or not.
Most of our river water originates in clear, bubbling mountain streams.
As the waters flow southward toward our desert, they dissolve and carry salts. At the
same time, evaporation into the hot, desert air reduces the volume of the water,
increasing the salt concentration. Finally reaching the fields along the Rio Grande,
the now somewhat salty irrigation water spreads out, some evaporating, some sinking
into the soil. In times of limited supply, the soil water lurks below, salt building up
until plentiful water flushes it below the root zone—or until the land lies
wasted. If continual drought is in the cards, we may well join ancient Babylon, done in
by the salt of the earth.
Listen to the Audio (mp3 format) as recorded by KTEP, Public Radio for the Southwest.
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.