Thursday, October 30, 2014

Who Should Pay to Fix the World's Salt-Damaged Soils?

Farms outside Baghdad as seen from a U.S. Army Blackhawk helicopter. Much of Iraq's soil has a high salt content because of flooding and poor drainage. (Credit: Jim Gordon/U.S. Army Corps of Engineers/Flickr) Click to enlarge.
Imagine losing about 5,000 acres, or 15 average-sized farms in Iowa, every day.  That's how much productive farmland has succumbed to salt damage in the last 20 or so years, according to a paper published Tuesday by a group of international researchers.  And, they say, all that degraded land is costing farmers $27.3 billion a year.

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.

That means "the farmers in salt-affected areas bear most of the cost of lost crop production," says Manzoor Qadir, lead scientist of the Water and Human Development Program at United Nations University and one of the authors of the paper, which appears in the UN Sustainable Development journal Natural Resources Forum.  But the consequences accumulate all the way up the chain to other businesses that use those agricultural products.
The good news is we can stop, and in many cases, reverse it.  According to Jack Watson, professor of soil physics at Pennsylvania State University, "salt doesn't disappear through any kind of biological or chemical means."  But the top layer of dirt can be flushed with extra water, pushing the salt down below the roots of the plants.
The pulp and paper, transportation, packaging, clothing, and even the travel industry should be digging deeper into their pockets.  Why?  Because the pulp and paper industry or clothing are directly affected by cotton production while transportation and packaging businesses are missing millions of shipments from areas that are producing less because of salt damage, like the Indus Basin in Pakistan or the Aral Sea Basin in Central Asia. 

The private sector, says Qadir, can afford to buy the technology and cover the labor costs that would help.  That might be a desalination plant, soil additives like gypsum that help absorb salt or land levelers to maintain the soil surface.  It could even be as simple as helping farmers plant salt-tolerant crops like licorice.

Read More at Who Should Pay to Fix the World's Salt-Damaged Soils?

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