The nitrogen dilemma: can we reduce fertilisers and still feed the world?
By Katie Burton in Geographical on October 15, 2019
"More than any other aspect of the climate crisis, it is the over-production of carbon dioxide that has been demonised – and rightly so. But nitrogen, and its abundant use in commercial fertiliser, also leads to air pollution and climate change.
A team of scientists, led by the University of California, Davis, has come up with a five-step plan to tackle this two-sided problem. Lead author, Benjamin Houlton, explains that only by undertaking a holistic approach and combining solutions can the problem be solved on both levels. ‘While we bring nitrogen efficiencies up and continue to work on that challenge, we also have to bring nitrogen to those communities that don’t have any access to it,’ he says.
The five steps identified involve changing agricultural practices (Houlton points to the use of slow-release fertiliser and other practices which help precisely deliver nutrients in proportion to crop demands), getting fertiliser to the places it’s needed (which Houlton says will require intergovernmental cooperation and policies to incentivise the private sector), reducing nitrogen pollution (restoring flood plains which can absorb nitrogen pollution from fertiliser run-off is key) and finally, both reducing food waste and promoting a change in diet. The latter two are essential because approximately one-quarter of all global food produced is wasted along the supply chain. This means that a large portion of the nitrogen fertiliser applied to crops is ultimately wasted."