Hurricane-loaded soil: effects on nitric oxide emissions from soil

Area of Science:

• Environmental Science
• Soil Science
• Atmospheric Chemistry

Background:

• Hurricane Floyd caused extensive flooding in North Carolina's Neuse River basin in September 1999.
• Flooding damaged hog lagoons and wastewater treatment plants, releasing untreated waste into the river basin.
• This resulted in increased concentrations of nitrogen, phosphorus, and total solids in the affected soils.

Purpose of the Study:

• To investigate the impact of hurricane-induced flooding on nitric oxide (NO) flux from soils.
• To quantify the difference in NO emissions between flooded and non-flooded soils.
• To assess the implications of increased NO flux on air quality and nitrogen conservation.

Main Methods:

• Laboratory experiments were conducted on soil samples from three sites in the Neuse River basin.
• Soils were collected from areas that experienced varying intensities of flooding from Hurricane Floyd.
• Nitric oxide (NO) flux was measured from both flooded and non-flooded soil samples.

Main Results:

• Soils subjected to hurricane flooding exhibited significantly higher nitric oxide (NO) emissions.
• NO fluxes from flooded soils were found to be more than 30 times greater than those from non-flooded soils.
• Measured NO fluxes ranged from 0.1 to 102.5 ng N/(m2 s) for flooded soils.

Conclusions:

• Hurricane-induced soil flooding substantially increases nitric oxide (NO) emissions.
• Elevated NO flux from soils can negatively impact lower troposphere ozone levels.
• Minimizing NO flux is crucial for protecting air quality and conserving nitrogen fertilizers.