Agricultural producers fertilise their crops to ensure a healthy, abundant and profitable yield that meets the increasing food demand. Nitrogen (N) is the most important fertiliser in crop production, mostly supplied through synthetic N-fertilisers, which are:
• Dependent on fossil fuels and energy-intensive: Fertilisers are produced by petrochemical companies using energy-intensive industrial Haber-Bosch process that depends on fossil fuels (mostly natural gas or coal) to produce ammonia (NH3). Thus, the price of nitrogen is highly dependent on changes in the price of natural gas.
• Pollutant and unsustainable: 70% of the N supplied with synthetic fertilisers is not absorbed by crops, resulting in soil and water pollution. Additionally, the supply chain (production and transport) of N-fertilisers entails a great amount of GHG emissions. Only in Europe, the direct cost derived from this contamination is estimated at €14 B/year.