Introduced in the early 1900s, synthetic fertilizers and crucially, the Haber-Bosch process, have revolutionised the way the global population is fed. An estimated 48% of crops today are grown with synthetic fertilizer, however, it cannot be ignored that its production and use is responsible for around 5% of annual greenhouse gas emissions. Clearly, a critical challenge for the fertilizer industry is the reduction of its carbon footprint, yet with the world’s population estimated to grow by 20% by 2050, it is also crucial for global food security to be maintained.
New research published in the journal Nature Food, by experts Yunhu Gao and André Cabrera Serrenho from the University of Cambridge, has examined the entire lifecycle of both synthetic and organic fertilizers.1 The study reports that surprisingly, the highest proportion of emissions are generated after fertilizer is spread on fields, as opposed to during the production process. The research represents the first instance in which fertilizer emissions have ever been tracked from production through to deployment; Serrenho notes that until now, very little has been known about the volume of chemicals produced across the world, or the emissions and waste generated by them. These new insights therefore present an unmissable opportunity for the industry to delve further into the potential solutions to help mitigate its carbon footprint.
The mitigation strategies presented in the new study involve a combination of measures; decarbonisation of the production process, improvement of fertilizer efficiency, and the use of a mix of fertilizer types, are among those discussed in the paper, inviting the sector to replace one of the biggest emitters, urea, with ammonium nitrate. Worldwide, Gao and Serrenho estimate that the latter alone could reduce around 20 – 30% of emissions.
The efficiency of fertilizers is unfortunately not a new concern for farmers, nor is it an easy fix. Much of the nitrogen in the fertilizer we use is lost through leaching,denitrification and volatilisation. Researchers at Agriculture Victoria, for example, recorded losses of up to 85% of nitrogen in the high rainfall zone of south-western Victoria, Australia, despite large amounts of nitrogen fertilizer being applied at the sowing stage.2 At present, the amount of in-crop mineralisation occurring in soil can only be estimated, making it almost impossible for farmers to predict how much fertilizer to use. Yet, the industry is seeing new innovations that could begin to alleviate these issues. Rapid soil tests are currently under development, which will accurately assess potential nitrogen mineralisation rates prior to sowing. Such innovations could put the industry on track to improve the efficiency of fertilizers, and as a result, use less product in order to reduce emissions.
By taking up the mitigation strategies outlined in their research, Gao and Serrenho deduce that the industry’s emissions could be reduced by 80% by 2050. Serrenho himself said, “there are no perfect solutions,” and certainly, the industry must continue to evolve and develop in order to reduce its carbon footprint, however the new information uncovered in the study represents a step in the right direction.
The agenda at CRU’s Nitrogen + Syngas conference this year is similarly focused on energy efficiency and low-emission technologies for ammonia and hydrogen production, as well as innovations in sustainability and?decarbonisation. The conference will also showcase the latest technologies, processes, and materials and equipment developments that are driving operational efficiency, sustainability, and reliability for nitrogen and syngas producers, so make sure to stop by the event in sunny Barcelona, and don’t forget to pick up a copy of World Fertilizer magazine while you’re there.
- GAO, Y., SERRENHO, A.C. (2023) Greenhouse gas emissions from nitrogen fertilisers could be reduced by up to one-fifth of current levels by 2050 with combined interventions, Nature Food,?doi:10.1038/s43016-023-00698-w
- www.agriculture.vic.gov.au/climate-and-weather/understanding-carbon-and-emissions/nitrogen-fertilisers-improving-efficiency-and-saving-money
