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Why is nitrogen so important?

Question and Answer | 31-03-2014

Nitrogen forms an essential part of amino acids and nucleic acids, both of which are essential to support of all life. Molecular nitrogen in the atmosphere cannot be used directly, whether by plants or animals, but needs to be converted to other compounds, or ‘fixed’, in order to be used by life. So nitrogen is an essential nutrient for plant growth and therefore very important for food production. In addition to its role in supporting life, many industrially important compounds, such as ammonia, nitric acid, urea and cyanides contain nitrogen.

In the early part of the 19th century, the use of nitrogen from droppings of sea birds (guano) on small islands off the Peruvian coast increased, but the guano deposits were rapidly depleted. For this reason, it is understandable that the English chemist, Sir William Crookes, claimed in a widely published lecture in 1898 that without a new source of nitrogen fertiliser famine would be inevitable within two to three decades.

Crookes then called on all chemists to find way to fix nitrogen chemically from the unlimited reserves in the air. Several attempts were made, and in 1908 Fritz Haber patented his synthesis of ammonia from the elements, nitrogen and hydrogen. The equipment used by Haber was later scaled up to a pilot plant and further to a commercial plant. By 1930, the amount of Haber-Bosch nitrogen was already equal to that from all other sources put together. However, the real increase in nitrogen fertiliser production took place between 1960 and 1970. The use of nitrogen fertilisers has played an essential role in the more than doubling of the global food production (and the world population) in the past 50 years. Of course, industrial nitrogen fixation has also led to large surpluses of nitrogen in agriculture.