Rene Geurts, a molecular biologist in Wageningen, is working on a more than 100-year-old question: can we get plants other than clover to coexist with bacteria that fix nitrogen from the air? This would be a solution to the global fertiliser problem.

Like all other life on Earth, plants need nitrogen, including for their proteins and DNA regulation. Although our atmosphere is 78% nitrogen gas (N2), this form of nitrogen is not useful to most organisms. It takes a lot of energy to break the triple bond between two nitrogen atoms. Most plants therefore use ammonia or nitrate to meet their nitrogen needs.