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

The nitric oxide (NO) flux from eastern North Carolina soils subjected to flooding from hurricanes were studied in laboratory experiments. Three sites along the Neuse River basin in eastern North Carolina that sustained different intensities of flooding in September 1999 from Hurricane Floyd were examined. Hurricane Floyd impacted the Neuse River basin by inducing flooding that damaged and disabled hog (Sus scrofa) lagoons and municipal wastewater treatment plants. Between approximately 53 and 325 million liters (14 and 86 million gallons) of untreated hog waste and between approximately 5.7 and 34.4 billion liters (1.5 and 9.1 billion gallons) of untreated municipal wastewater are projected to have entered the Neuse River basin, increasing the concentrations of nitrogen (N), phosphorus (P), and total solids. Phosphorus and total solids are projected to have increased 3.2 and 199.2 mg/L, respectively. Total N was projected to have increased by 9.8 mg/L, which is posited to have increased the NO flux from flooded soils for months after the hurricane. Nitric oxide emissions from soil can adversely affect ozone levels in the lower troposphere. Minimization of NO flux from soil is advantageous, protecting air quality as well as conserving valued nitrogen fertilizers. Hurricane-loaded soils were found to produce more than 30 times greater NO emissions than nonflooded soils with NO fluxes ranging from 0.1 to 102.5 ng N/(m2 s).