Abstract
Laboratory studies were conducted to evaluate the relationship between soil water content and microbial response to soil nitrogen (N) in petroleum-contaminated soils. Various levels of N were added to a sand, a sandy loam, and a silt loam. Measurements of the extent of biodegradation in each soil (petroleum loss or CO2 production) indicated that biodegradation was related to soil N expressed as a function of soil water (mg N/kg soil H2O or mg N/l) better than N expressed as a function of soil dry matter (mg N/kg soil). A loamy sand was treated with four levels of N (0, 250, 500, 750 mg N/kg soil) and incubated at three water contents (5.0, 7.5, and 10.0% on a dry soil weight basis). Soil water potential and O2 consumption were best related to N expressed on the basis of soil water. It is concluded that expressing N in units of mg N/kg soil H2O (easily obtained by dividing [mg N/kg dry soil] by [soil moisture content]) can be used to determine fertilization rates for bioremediation processes. On this basis, an optimum N level of approximately 2000 mg N/kg H2O is tentatively identified for the range of soils and conditions tested.
Original language | English (US) |
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Pages (from-to) | 465-480 |
Number of pages | 16 |
Journal | Soil and Sediment Contamination |
Volume | 6 |
Issue number | 5 |
DOIs | |
State | Published - 1997 |
Keywords
- Bioremediation
- Nutrient
- Salinity
- Water potential
ASJC Scopus subject areas
- Pollution
- Soil Science
- Health, Toxicology and Mutagenesis
- Environmental Chemistry