The Abiotic Nitrogen Cycle

Natural environments on Earth are amenable to a diverse array of chemical reactions that can convert one form of nitrogen into another, often with the participation of additional substances such as minerals, dissolved metals, and organic compounds. These processes collectively define a natural chemical nitrogen cycle, analogous to the familiar biologically driven cycle but even more intricate with respect to the number of pathways by which nitrogen can be transformed and transported across land, air, and water. The fully assembled abiotic nitrogen cycle manifests a landscape rich in opportunities for investigation either with or without parallel attention to biological processes.