Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/21/2004
Publication Date: 4/21/2004
Citation: Vlaminck, S., Johnson, J.M., Carpenter, N. Nitrous oxide: Why and how. University Minnesota-Morris Undergraduate Research Symposium. 2004. Abstract p. 27.
Technical Abstract: Nitrous oxide (N2O) is an important trace gas, which contributes to the greenhouse effect and is linked to the depletion of the stratospheric ozone layer. The atmospheric concentration of N2O is about one tenth the concentration of carbon dioxide (CO2), but its radiative force is at least 200 times that of CO2. Agriculture is a major contributor to the recent increase in atmospheric N2O, mainly through nitrogen fertilization. Nitrous oxide production is affected by temperature, water availability, aeration, nitrogen form and concentration. The experimental goal was to test a chamber design and sampling protocols (sample collection time) for collecting field samples of trace gases, including N2O. Chambers and collars were designed using polyvinylchloride. Vented chambers were notched to fit snuggly over the collars (25.6 cm diameter by 7 cm height) and had a volume of 969 cm**3. Gas samples were taken in small field plots that were either 1) not watered and not fertilized, 2) not watered but fertilized, 3) watered only and 4) watered and fertilized. The fertilizer had 3.75% ammonium phosphate, 5.2% nitrate and 11.05% urea nitrogen and was applied at a rate of 1 L of 200 mg N L**-1. After fertilizing, N2O production was monitored by collecting gas every 15 minutes for 90 minutes from the chamber with a 3-mL polypropylene syringe through a stopcock on the chamber. The concentration of N2O was measured by GC-electron capture chromatography. Nitrous oxide flux is calculated by determining the change in concentration over time.