Professor Deli Chen is an eminent soil scientist and internationally recognised authority on the efficiency of nitrogen fertiliser use and its impact on global food security, the environment and climate change. His novel techniques to measure soil nitrogen transformations have led to increased crop productivity while minimising environmental damage. Professor Chen has developed high efficiency nitrogen fertilisers and formulated strategies to mitigate greenhouse gas emissions from crop and livestock systems. These achievements have transformed agro-environmental sciences and his innovations on nitrogen and agricultural land management have been taken up by industry and governments worldwide.