Professor Hong Di, Lincoln University, is a world-leading authority on the molecular biology of nitrogen transformations in biogeochemical systems. He has led pioneering research, scholarship and technology development on ammonia oxidisers in the soil, nitrate leaching and nitrous oxide emissions. His ground-breaking research has significantly improved fundamental understanding of the role of bacteria and archaea in nitrogen cycling. He is recognised internationally for his seminal work and publications on nitrification inhibitors which represents an outstanding contribution to the development of innovative environmental technologies to mitigate nitrate leaching and nitrous oxide emissions. In recognition of his outstanding contribution, Hong Di was made an Officer of the New Zealand Order of Merit in the 2008 Queen’s Birthday Honours for Services to Agricultural Research.