Fixing Nitrogen

About this episode

<p>Today, 3.5 billion people are alive because of a single chemical process. The Haber-Bosch process takes nitrogen from the air and makes ammonia, from which synthetic fertilizers allow farmers to feed our massive population. Ammonia is a source of highly reactive nitrogen, suitable not just for fertilizer, but also as an ingredient in bomb making and thousands of other applications. </p><p>We make around 100 million tonnes of ammonia annually - and spread most of it on our fields. But this is a very inefficient way to use what amounts to 1-2% of the planet's energy needs. Only around 20% of fertilizer made ends up in our food. </p><p>Professor Andrea Sella explores some of the alternative ways we might make fertilizer. Vegetables such as peas and beans, allow certain cells in their roots to become infected by a specific type of bacteria. In return, these bacteria provide them with their own fertilizer. Could we infect the plants we want to grow for food – such as cereals – in a similar way to cut down the climatic and environmental impact of Haber-Bosch?</p>