A perspective on reactive nitrogen in a global, Asian and Indian context

Abstract

Reactive nitrogen (Nr) includes the inorganic (NH3, NH 4+ , NOx, HNO3, N2O, NO3-) and organic forms (urea, amines, proteins, nucleic acids) that readily participate in various reactions of the global N cycle. Over the last half a century, anthropogenic perturbations of the natural N cycle have led to the increasing accumulation of inorganic Nr in the soil, water and air, intentionally through agriculture and unintentionally through fossil-fuel consumption and other activities, adversely affecting human health, biodiversity, environment and climate change. One of the major emerging challenges of this century will be to ensure adequate availability of Nr inputs for agriculture and other activities, while preventing their unwanted accumulation. This article provides an overall perspective of the emerging issues related to Nr in the global, Asian and Indian contexts.