IAN Seminar Series

More than half of the people in the world are nourished by crops grown with synthetic nitrogen (N) fertilizers.  However, more than a billion people are still undernourished, and global population will increase by 2-3 billion by 2050, which means that demand for N fertilizers is likely to grow.  Unfortunately, unintended adverse environmental and human health consequences of reactive N escaping agricultural fields are occurring as groundwater contamination, eutrophication of freshwater and estuarine ecosystems, atmospheric pollutants related to nitrogen oxides and ammonia gas emissions, and accumulation of the potent greenhouse gas and stratospheric ozone depleting substance, nitrous oxide.   An alternative to increasing fertilizer-N use proportionately to the increase in food demand is to improve nitrogen use efficiency (NUE) in agriculture.  I will present preliminary results from an analysis of trends in NUE from 1961 to 2011 for 129 countries, demonstrating the importance of both crop mix and policy.  In