3rd UF Water Institute Symposium Abstract

Submitter's Name Jing Hu
Session Name Posters - Nutrient Dynamics and Enrichment Impacts in Aquatic Ecosystems 1
Category Nutrient dynamics and enrichment impacts in aquatic ecosystems
Poster Number 32
Author(s) Jing  Hu,  Univerisity of Florida (Presenting Author)
  Kanika Inglett,  Unversity of Florida
  Clark Mark, University of Florida
  Ramesh Reddy, University of Florida
  Hydrological and Biogeochemical Controls on the Nitrous Oxide (N2O) Production and Consumption in Subtropical Isolated Wetlands
  Wetlands are potential sources of greenhouse gases including nitrous oxide (N2O). N2O emissions are highly regulated by the wetland hydroperiod and water-table fluctuations. To reduce N2O emissions and to develop mitigation strategies, it is important to understand the effect of hydrology and biogeochemical factors on production and consumption of N2O in soils. The objective of this study was to quantify the potential soil N2O production and consumption rates within soil profile. Laboratory incubation experiments were carried out using soils from an isolated wetland located in agricultural watershed in the Okeechobee Drainage Basin. Soil samples were collected at four depths (0-10cm, 10-30cm, 30-50cm, and 50-70cm) from three areas with different hydroperiods. Soil physical and chemical properties and microbial biomass were performed on soil subsamples. Potential rates of N2O production from nitrification (PN2O-nit), and denitrification (PN2O-den) and consumption (PN2O-con) were determined for all soil samples. The results indicated higher N2O potential production rate in soils from location with higher water table. Most of the N2O production (~70%) and consumption (~80%) in soils occurred in the upper layer (0-10cm) and N2O was mainly produced by denitrification. Furthermore, microbial biomass and nitrate content were two critical factors that controlled N2O production and consumption along the soil profile.