Brian Merchant flags a study claiming that salt degradation “has caused tens of billions of dollars worth of damage, mars an area of cropland the size of Manhattan every week, and has hit nearly one-fifth of the world’s farmland so far”:
“Salts have damaging effects whether they are in excess amounts in the human body or in agricultural lands,” Manzoor Qadir, the lead author of an eye-opening new study on the subject, published by the United Nations’ Institute for Water, Environment and Health, told me in an email conversation. “If salt degradation goes on unchecked, more and more land will be highly degraded leading to wasteland,” he said. “Restoring such lands will not be economically feasible at all.”
Alison Bruzek provides more details:
Rainfall and irrigation systems designed for lots of drainage usually keep salt from building up in the soil. But as climate patterns shift and more farmers irrigate without sufficient drainage, evaporated salt is crusting on top dirt clumps around the world — especially in places like Central Asia. Normally, soil has anywhere from zero to 175 milligrams of salt per liter. Once that level exceeds 3,500 milligrams per liter, it’s next to impossible to grow anything, including major crops like corn, beans, rice, sugarcane and cotton. …
No one had really studied the economic impacts of salt-damaged land, says Qadir. But now that the UN Food and Agriculture Organization has projected that we need to produce 70 percent more food by 2050, the salinity problem is becoming a much higher priority issue. On the 1-to-10 scale of land sustainability problems, “erosion is an 8 … high-saline soils is a 2 problem,” Chuck Benbrook, research professor at the Center for Sustaining Agriculture and Natural Resources at Washington State University, tells The Salt in an email.
The Dish 