New environmental research has found that fertilizer and pesticide applications have replaced fossil fuels as the largest human source of sulfur in the environment.
According to researchers, sulfur amounts have soared up to 10 times higher than the peak sulfur load identified in the second half of the 20th century, during the days of acid rain.
“Sulfur in agriculture is used in many different forms, and we haven't studied broadly how those different forms react in the soil,” said Eve-Lyn Hinckley, lead author of the study, assistant professor of environmental studies and fellow at the Institute of Arctic and Alpine Research at the University of Colorado Boulder. “No one has looked comprehensively at the environmental and human health consequences of these [agricultural] additions.”
Sulfur is a naturally occurring element and an essential plant nutrient that assists with the return of nitrogen. It is mined to produce fertilizers and pesticides. It is also highly reactive and undergoes chemical transformations that affect the wellness of ecosystems and pose a danger to wildlife and humans.
In the past, coal-fired power plants were the largest origin of reactive sulfur, creating acid rain and contributing to the decline of aquatic and forest ecosystems in the U.S. and Europe.
Historically, sulfur has been applied to agricultural lands, in the form of both a fertilizer and pesticide, to boost the production and health of crops.