|OVERSTREET, JR, K|
Submitted to: Symposium on Biochemistry Of Wetlands
Publication Type: Abstract Only
Publication Acceptance Date: 2/1/1996
Publication Date: N/A
Technical Abstract: Nitrogen is an essential plant nutrient, but in excess concentration can contribute to eutrophication of freshwater and coastal aquatic ecosystems. In the southeast U. S., a major source of nitrogen loading to aquatic ecosystems is soil-laden runoff from agricultural fields. A management practice to reduce soil loss, currently being tested in the Mississippi Delta, is to flood agricultural fields by raising outlet levels at drainage pipes during the fall and winter months. During this period, the fields may be inundated with water for up to four months at a time, in effect creating temporary wetlands. Because of the importance of nitrogen as both a agricultural nutrient and a potential pollutant, we have been examining the effect of managed flooding on the nitrogen cycle in Mississippi Delta agricultural fields. We hypothesize that during the period of flooding, processes that are important in nitrogen cycling in natural wetlands will develop in these temporary wetlands. Using soil cores from a soybean field, we have been examining the effect of seasonal flooding on soil nitrogen concentrations, nitrogen speciation, and rates of denitrification. The results of these studies will assist in evaluation of the effect of managed flooding on the magnitude and mechanisms of nitrogen export from agricultural fields.