Nitrogen in Grain Production Systems

Nitrogen comprises 78% of the earth’s atmosphere, and is vital to life as a component of the amino acids that make up proteins. The nitrogen cycle – or nitrogen web – describes the movement of nitrogen from the atmosphere, to plants and other living organisms, and back to the atmosphere. The industrial fixation of atmospheric nitrogen to make nitrogenous fertilizers to support high-productivity plant agriculture is essential to support the large and growing world population. Such industrial fixation uses the Haber-Bosch process, with catalysis, high temperature, and high pressure, and is therefore very demanding in terms of energy inputs. Rhizobial nitrogen fixation allows roots of leguminous plants to fix their own nitrogen. Nitrogen, as protein, most accessible for human food, is deposited in storage reserves in the grain.