Drivers of ammonia volatilization in Mediterranean climate cropping systems.

Ammonia (NH) volatilization is the major source of nitrogen (N) loss resulting from the application of synthetic and organic N fertilizers to croplands. It is well known that in Mediterranean cropping systems, there is a relationship between the intrinsic characteristics of the climate and nitrous oxide (NO) emissions, but whether the same relation exists for NH emissions remains uncertain. Here, we estimated the impact of edaphoclimatic conditions (including meteorological conditions after N fertilization), crop management factors, and the measurement technique on both the cumulative emissions and the NH emission factor (EF) in Mediterranean climate zones, drawing on a database of 234 field treatments.