Science, Vol. 340
April 12, 2013
Latin America (LA) has many social indicators similar to those of highly developed economies but most frequently falls midway between least developed countries and industrialized regions. To move forward, LA must address uncontrolled urbanization, agricultural production, social inequity, and destruction of natural resources. We discuss these interrelated challenges in terms of human impact on the nitrogen (N) cycle. Human activity has caused unprecedented changes to the global N cycle; in the past century; total global fixation of reactive N (Nr) has at least doubled. Excess Nr leaked into the environment negatively affects soils, atmosphere, and water resources in temperate zones. In addition to N excess from human impact, mining of natural soil N creates N deficits in some regions.