Around 100 scientists from China and Britain will gather on Friday to discuss projects aimed at reducing farmers' reliance on nitrogen-based fertilizers, products that can help crops but damage other aspects of the environment.

The work is continuing at the Rothamsted research center in Hertfordshire, north of London.

Ju Xiaotang, a professor at the College of Resources and Environmental Science at China Agricultural University, said: "Nitrogen fertilizer management is crucial for China to ensure healthy and sustainable food supply, while keeping pollution to a minimum.

"China can learn great lessons from the UK's nitrogen management policies and technologies, and we as academics play a big role in helping the Chinese government to support new technology through policies, and help Chinese farmers to use these technologies in practice."

Nitrogen is a chemical that causes severe pollution in China. To tackle the problem, the government has committed to achieve zero growth in the use of polluting chemical fertilizers by 2020.

Two nitrogen research projects that began a year and a half ago that are funded by the Chinese and British governments have just concluded their first phase, which focused on identifying the amount of nitrogen overuse in China and understanding more about the nature of nitrogen.

The first phase identified that 40-50 percent of Chinese farms use too much nitrogen. The second phase, which begins with the latest discussions, will examine specific solutions that can be deployed in China. The third phase will look at trialing these solutions on some of the projects' partner farms in Beijing and Nanjing.

Friday's conference is organized by the China-UK Sustainable Agriculture Innovation Network, which was launched in 2008 by both countries to promote agricultural collaboration.

Lu Yuelai, head of secretariat of the SAIN network, said academics play a key role in devising strategies to help China and other emerging economies ensure food security while managing nitrogen fertilizer use, because some degree of nitrogen use is still needed to ensure an adequate food supply.

In some of China's most intensive farming areas, the use of nitrogen fertilizer is as much as 350 kilograms per hectare. In the UK, the average nitrogen fertilizer application rate is about 140 kilograms per hectare.