Solving the nitrogen problem in food production

Abstract

Nitrogen is an essential element for life, being a key elemental ingredient of proteins, DNA and RNA.  While nitrogen is a common element, it generally exists as molecular dinitrogen in the atmosphere and most organisms are unable to use this form of nitrogen. Reactive forms of nitrogen that can be utilised in cellular metabolism are much rarer and this is often a limiting factor in plant growth. As a result modern agricultural practices involve extensive use of nitrogen fertilisers to promote crop productivity. Excessive use of nitrogen in developed nations has led to extensive nitrogen pollution, particularly in aquatic systems such as rivers, lakes and seas. In contrast farmers in developing nations cannot afford nitrogen fertilisers and their crop productivity suffers as a result.  Hence, breaking agricultural dependence on nitrogen fertilisers would reduce pollution in the developed world and could raise crop yields in the developing world.

 Some species of plants have evolved the capability to associate with nitrogen-fixing bacteria, essentially making the large supply of atmospheric dinitrogen available for plant growth. Unfortunately our major crop plants, wheat, rice, maize etc. are unable to form this nitrogen-fixing symbiosis. Research over the last few decades have defined the genetic components present in plants that allows the association with nitrogen-fixing bacteria and this positions us to start the process of engineering nitrogen-fixing cereal crops. 

Host: Professor Bob White