+/- 20% Of Planet's Cropland Facing Salination Threat; Overirrigation, Global Warming, Overuse Main Drivers Of Trend
The extent of the worlds land affected by excess salt is set to increase rapidly with potentially devastating impacts on food production, research has found. About 1.4bn hectares (3.4bn acres), amounting to 10% of global land, is affected by salinity, with a further 1bn hectares classed as at risk, a report from the UN Food and Agriculture Organization has found.
This is already having a serious impact on agriculture, as globally about a tenth of irrigated cropland and a similar proportion of rain-fed cropland is afflicted by excess salt. The potential losses to crop yields are as high as 70% in some cases. Some of the worlds largest and most populous countries are particularly badly hit, including China and the US, Russia, Australia and Argentina. The central Asian region is also a hotspot, with Afghanistan, Kazakhstan, and Uzbekistan badly affected, while Iran and Sudan also rank among the countries suffering the worst effects. These 10 countries account for 70% of salt-affected soils globally.
Climate breakdown and poor agricultural practices are to blame, the FAOs scientists found, in the first major assessment of the issue in 50 years. As temperatures rise, the extent of salt-affected soils is likely to increase to between a quarter and a third of all land by the end of this century, if current trends are not arrested.
While some salts are needed for crops, excess salinity reduces soil fertility. Too much salt absorbs water, making less available for uptake by plants. The salt also changes the physical structure of soil, causing it to clump together, and makes it more vulnerable to erosion. Water scarcity, poor drainage, and overexploitation of the soil are key factors behind the increase in salinity. Sea level rises will exacerbate this, with the incursion of saltwater into coastal areas.
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https://www.theguardian.com/environment/2024/dec/11/global-food-production-at-increased-risk-from-excess-salt-in-soil-un-report-warns