A 30% cut in fertiliser use in China would not threaten food security
17 February 2010
A study published in Science shows that over-use of ammonium-based fertilisers in China has caused soil acidification that is 100 times greater than that associated with acid rain. This has implications for the protection of ecosystems and their biodiversity and has led to a significant rise in emissions of the harmful greenhouse gases, carbon dioxide and nitrous oxide. In addition, large amounts of nitrogen are released as ammonia which further contributes to acid rain. Scientists from Rothamsted Research, an institute of BBSRC, are collaborating with Chinese researchers to achieve optimal crop yields with reduced fertiliser inputs and to prevent environmental damage.
In an effort to meet the food demands of a growing population, China has relied upon the use of chemical fertilisers to increase crop yields. Around 30% of the global production and use of nitrogen (N) fertiliser occurs in China and this has led to cropland soils becoming significantly more acid.
Rothamsted Research scientist and co-author, Professor Keith Goulding said "Nitrogen is known to be the key nutrient controlling crop yields in most parts of the world but inputs, whether as fertilisers, manures or fixation by legumes, must match crop needs. If not, the excess is likely to be lost to air and water. Our research shows the long-term and sometimes unsuspected effects that such losses can have. It would take 3-4 tonnes of chalk for every hectare of land, every year to prevent this and ten times as much in the very intensive glasshouse production systems used in China".
China and the UK are committed to achieving a low carbon economy and reducing the harmful impacts of agriculture on the environment, but this has to be balanced against achieving food security for an increasing global population. There is widespread proof that the use of nitrogen fertilisers could be cut by 30%, with no loss to crop production. To this end Prof. Goulding and Prof. David Powlson of Rothamsted Research are collaborating with their Chinese colleagues to promote improved nitrogen management. This collaboration led to the production of the first Chinese National Fertilizer Recommendations by the China Agricultural University in Beijing. These are based on the Defra-backed recommendations used by British growers, commonly referred to as 'RB209'.
Professor Powlson said "The impact of N fertiliser over-use on greenhouse gas emissions is often overlooked. It arises through the carbon dioxide, emitted when manufacturing fertiliser, and nitrous oxide, a powerful greenhouse gas, emitted when N fertiliser is applied to soil. Our work with Chinese collaborators shows that reductions in N use of 30% and, in some cases, much more are possible without any threat to China's food security, and would make a significant contribution to reducing total greenhouse gas emissions from China. Avoiding N fertiliser over-use is a "multiple win": farmers save money, there is less water pollution, smaller greenhouse gas emissions, and a smaller acidification burden on soil and water".
Professor Goulding added "China has to feed its growing population, but is becoming more and more aware of the impact of its push for productivity. We are delighted to be able to contribute to Chinese efforts to produce food whilst reducing inputs and protecting its environment".
Notes to editors
The research was published in the February 11 edition of Science Express and will be published in the February 19 issue of Science as "Significant Acidification in Major Chinese Croplands" by J.H Gou, X.J. Liu, Y. Zhang, J.L. Shen, W.X. Han, W.F. Zhang, P.Christe, K. Goulding, P. Vitousek, F.S. Zhang. This work was supported by the National Basic Research Program of China (2009CB118600 & 2005CB422206) and the Innovative Group Grant from NSFC (30821003) and the Special Fund for Agricultural Profession (200803030).
Professor Keith Goulding is a visiting Professor at the China Agricultural University in Beijing and is collaborating with Defra to update the UK's fertilizer recommendations.
Professor David Powlson is a Lawes Trust Senior fellow and working on 2 UK-China projects "Improved Nutrient Management in Agriculture- a Key Contribution to the Low Carbon Economy" which is funded by the Foreign and Commonwealth Office and by China's Ministry of Agriculture. The other is "Improving livelihoods on Shaanxi farms by reduced non-point N pollution through improved nutrient management" funded by DFID.
For further information, please contact Professor Keith Goulding - tel: 01582 763133 ext 2627, email@example.com
About Rothamsted Research
Rothamsted Research is centred in Harpenden Hertfordshire and is the largest agricultural research institute in the country. The mission of Rothamsted Research is to be recognised internationally as a primary source of first-class scientific research and new knowledge that addresses stakeholder requirements for innovative policies, products and practices to enhance the economic, environmental and societal value of agricultural land. The Applied Crop Science department is based at Broom's Barn, Higham, Bury St. Edmunds. North Wyke Research is located near Okehampton in Devon. See external contact below or visit: http://www.rothamsted.ac.uk
BBSRC is the UK funding agency for research in the life sciences. Sponsored by Government, BBSRC annually invests around £450M in a wide range of research that makes a significant contribution to the quality of life in the UK and beyond and supports a number of important industrial stakeholders, including the agriculture, food, chemical, healthcare and pharmaceutical sectors.
BBSRC provides institute strategic research grants to the following:
- The Babraham Institute
- Institute for Animal Health
- Institute for Biological, Environmental and Rural Studies (Aberystwyth University)
- Institute of Food Research
- John Innes Centre
- The Genome Analysis Centre
- The Roslin Institute (University of Edinburgh)
- Rothamsted Research
The Institutes conduct long-term, mission-oriented research using specialist facilities. They have strong interactions with industry, Government departments and other end-users of their research.
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