Imagine once healthy farmland rich with the signs of life reduced to a barren wasteland. Even as you walk across it, a strange white crust crunches under your feet, reminding you of the root of the problem: salt. A team of international experts has now found that salt poisoning costs the world an additional 2,000 hectares of agricultural soil every day, and while some of this is natural, a large part can be blamed on irrigation.
Salt is naturally present in most soil already. However, if left to accumulate with the help of irrigation, increasingly high levels of salt can cut crop yields by 15 to 70 percent, and eventually render entire swaths of farmland unusable.
Now, a new agriculture assessment from the United Nations has found that salt poisoning is affecting more than a fifth of the world's irrigated soil, and is leading to a gradual loss in productive farmland.
The study, Economics of Salt-induced Land Degradation and Restoration, was based on data compiled in an international effort by researchers from Canada, Jordan, Pakistan, and Sri Lanka. Paying special attention to instances of salt poisoning among irrigated cropland, agricultural and economic experts found that salt poisoning is costing the world a whopping $27.3 billion (USD) in lost crop production. (Scroll to read on...)
"There are other cost implications such as employment losses, increase in human and animal health problems, and treatment costs, infrastructure deterioration (including roads, railways, and buildings), losses on property values of farms with degraded land, and the social cost of farm businesses," the researchers added. "In addition, there could be associated environmental costs as these lands emit more carbon thus contribute to global warming."
With these indirect factors considered, that $27.3 billion is but a drop in the bucket of salt poisoning costs, especially as the world's reliance on irrigation continues to grow. However, a "salt apocalypse" is not upon the world's farmers just yet.
The authors found that bringing salt-damaged farmlands back into use with the help of trusted chemicals such as gypsum could help. Improving the maintenance and quality of irritation systems to cut down deposited salinity is another option.
The study also acknowledges that these solutions are costly and sometimes even impossible. Most regions that employ strictly irrigated farmland do so because of their lack of regular precipitation in the first place, which makes the regular flushing of accumulating salt a difficult task.
However, the authors are quick to add that "salt-affected lands are a valuable resource that cannot be neglected nor easily abandoned."
"To feed the world's anticipated nine billion people by 2050, and with little new productive land available, it's a case of all lands needed on deck," principal author Manzoor Qadir said in a statement. "We can't afford not to restore the productivity of salt-affected lands."