Ammonia emissions from two fertilized wheat fields

摘要

The NH(sub 3) emissions from two winter wheat fields have been measured with a new variant of the gradient technique. Wind speed weighted, weekly average NH(sub 3) concentrations and the average wind speed were determined using passive samplers. One of the fields received an optimum amount of nitrogen fertilization and the second field 60% of the optimum. The measurements started on June 11th and ended on the day of harvesting (Aug 3rd, 1992). The measurements clearly show that the NH(sub 3) emissions equal the NH(sub 3) deposition from the atmosphere, and that the two fluxes are very small and negligible compared to the nitrogen content of the crop. An explanation to this may be that the summer was unusually warm and dry. No loss of nitrogen could be detected from the weekly crop analyses. 6 refs, 8 figs, 2 tabs