A team of scientists from the University of Aberdeen have discovered how ammonia in fertilisers is converted to nitrate, which is then washed out of soils before reaching the intended crops. The team hopes their research will lead to improved efficiency in fertiliser use and a reduction in pollution.

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Although organisms that oxidise ammonia were discovered in 1890, efforts to cultivate strains of the microbe were only successful at higher (alkaline) and neutral pH, and not in acidic conditions.

However, soil microbiologists at the University of Aberdeen have successfully identified the microorganism which oxidises ammonia in acidic conditions; these conditions account for 50 per cent of the world’s agricultural soils. The team claim the discovery will demystify the process of fertiliser loss in acidic soils.

The research team has been awarded a £0.5 million, 3.5-year research grant by the Natural Environment Research Council to investigate the highly unusual physiology of the new organism and find out more about its potential role in the loss of ammonia-based fertilisers and nitrous oxide gas emissions from soil.

The scientists responsible for the discovery said their work may contribute to addressing problems of food security and could make fertiliser use more efficient. Over the next fifty years scientists have predicted that, due to the requirements of a rising world population, the use of fertilisers could double.

Currently, the most used macronutrients in agricultural fertilisers are relatively inefficient; according to Martin Lane of Field Science Ltd, nitrogen is around 50 per cent efficient, phosphorus is 10 per cent efficient and potassium is 40 per cent efficient when used without triggers such as seaweed to aid nutrient uptake.

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