Faces, Places, and Excursions Along the Nitrogen Trail.

Commercial nitrogen (N) fertilizers have significantly contributed to higher crop yields and thereby helped support the dietary needs of millions of people. A little over a century ago, Haber and Bosch invented a procedure to produce anhydrous ammonia from N in the atmosphere. It wasn’t until the late 1940s that the output of the technology was directed to producing are variety of N fertilizers that were widely promoted for agricultural crops. By the mid-1960s, soil scientists began cautioning producers about the perils of over-application of N fertilizers and the potential for contamination of surface and ground water. This warning and occurrence of alarming concentrations of nitrate in groundwater and hypoxic conditions in lakes and oceans fostered a variety of research activities that included: isotopic N studies to characterize the fate of N fertilizers applied to soil; studies of volatile N losses; many fertilizer N rate, placement, source, and timing experiments; model development efforts to help optimize N management; remote sensing to characterize spatial variability; implement development and instrumentation for site-specific management and related geo-spatial data collection and analysis;  development of products to reduce N losses and increase nitrogen use efficiency; and a fledgling effort to integrate technologies so as to optimize profitability while addressing environmental concerns. Scientists have every right to be proud of their contribution to the nitrogen trail and the fine legacy they have left to future generations.