Reducing the environmental impacts of fertiliser use

Scientists have demonstrated how improvements in nitrogen fertiliser manufacture and their application could help reduce China's agricultural greenhouse gas emissions by around 60%, by 2030, compared to the current business as usual approach. This emissions reduction represents a 2 to 6% reduction in China's overall greenhouse gas emissions and therefore could be significant in the global battle on climate change.

In a paper published in the Proceedings of the National Academy of Sciences of the USA, the team from Rothamsted Research and China Agricultural University, working alongside other scientific colleagues in the UK and China, have quantified the total GHG emissions associated with nitrogen (N) fertiliser manufacture and use in China. They then examined several scenarios for reducing over-use and mis-use of N fertiliser, and for changing manufacturing processes, and calculated the decreases in greenhouse (GHG) emissions that could be achieved.

In this study, funded by the UK Foreign and Commonwealth Office and linked closely with projects funded by the Chinese Ministry of Agriculture, the UK-China team concluded that a combination of technical innovations in manufacturing and changes in agricultural management could result in annual GHG emissions being reduced to of 204 teragrams of carbon dioxide equivalents (Tg CO2-eq) instead of the projected 542 Tg CO2-eq by 2030*.

The UK leader of the project, Professor David Powlson said "China is the world's biggest manufacturer and user of N fertiliser accounting for around 30% of global manufacture. A large use of N fertilizer is necessary for the nation to feed its 1.3 bn inhabitants. However, there is scope for using N far more efficiently: there is now clear evidence of widespread over-use and inefficient use of N fertiliser in China. For example there is evidence of 30 - 60% over-use in some regions"

This project came under the China-UK Sustainable Agriculture Innovation Network, SAIN (www.sainonline.org) that specifically supports research that has relevance to agricultural and environmental policies.

The paper is available at:  www.pnas.org/content/early/2013/05/08/1210447110 (10.1073/pnas.1210447110).