China farming soil acidification ‘at least 10 to 100 times greater than acid rain’
By Jeremy Hance, www.mongabay.com
February 11, 2010
A new study in Science shows that farming practices in China are acidifying the nation’s soils and threatening long term productivity at a time when food concerns worldwide have never been higher. The culprit is the increasing use of nitrogen fertilizer. “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 authors explain. … In some select areas “soils are approaching pH values at which potentially toxic metals such as Al and manganese (Mn) could be mobilized,” the authors write, concluding that “overall, anthropogenic acidification driven by [nitrogen] fertilization is at least 10 to 100 times greater than that associated with acid rain.” …
