China's Fertilizer Fetish Making Soils More Acidic - Up to 100 Times Worse Than Acid Rain
photo: Simply Lori Ann
Brian recently told us about how China's water pollution problems are probably twice as bad as official government statistics show. Part of that is due to agricultural run-off from excessive fertilizer use. But water isn't the only thing being polluted by too much fertilizer. Mongabay highlights a new article in Science which details who China's soils are acidifying because of bad agricultural practices:
Chinese agriculture has intensified greatly since the early 1980s on a limited land area with large inputs of chemical fertilizers and other resources," the authors note, pointing out that nitrogen fertilizer consumption in China reached 32.6 million tons in 2007, an increase of 191 percent over 1981 levels.
The rates of [nitrogen] applied in some regions are extraordinarily high as compared with those of North America and Europe. These have degraded soils and environmental quality in the North China Plain and in the Taihu Lake region in south China.
The scientists examined pH levels of soils going back to the 1980s and found that on average pH has declined by 0.13 from then until the 2000-2008 period. In areas where cash crops predominated average pH dropped by 0.30. Overall, the authors says, "anthropogenic acidification driven by [nitrogen] fertilization is at least 10 to 100 times great than that from acid rain."