Air pollution legislations have controlled sulphur levels: Study

摘要

Air pollution legislation to control fossil fuel emissions and the associated acid rain has worked - perhaps leading to the need for sulphur fertilizers for crop production. A University of Illinois study drawing from over 20 years of data shows that sulphur levels in Midwest watersheds and rivers have steadily declined, so much so that farmers may need to consider applying sulphur in the not too distant future.