Nitrogen and carbon flow from rock to water: Regulation through soil biogeochemical processes, Mokelumne River watershed, California, and Grand Valley, Colorado
Journal of Geophysical Research F: Earth Surface
Links
- More information: Publisher Index Page (via DOI)
- Open Access Version: Publisher Index Page
- Download citation as: RIS | Dublin Core
Abstract
Soil denitrification is an ecologically important nitrogen removal mechanism that releases to the atmosphere the greenhouse gas N2O, an intermediate product from the reduction of NO3- to N 2. In this study we evaluate the relationship between soil carbon and denitrification potential in watersheds with bedrock acting as a nonpoint source of nitrogen, testing the hypothesis that nitrate leaching to stream water is in part regulated by denitrification. Two sites, one in a Mediterranean climate and the other in an arid climate, were investigated to understand the interplay between carbon and denitrification potential. Both sites included carbonaceous bedrock with relatively high nitrogen concentrations (> 1,000 mg N kg-1) and had low background nitrogen concentrations in surface and groundwater. There was a net accumulation of carbon and nitrogen in soil relative to the corresponding bedrock, with the exception of carbonaceous shale from the arid site. There the concentration of carbon in the soil (15,620 mg C kg-1) was less than the shale parent (22,460 mg C kg-1), consistent with the bedrock being a source of soil carbon. Rates of denitrification potential (0.5-83 ??g N kg-1 hr-1) derived from laboratory incubations appeared to be related to the ratio of dissolved organic carbon and nitrate extracted from soils. These data indicate that microbial processes such as denitrification can help maintain background nitrogen concentrations to tens of ??M N in relatively undisturbed ecosystems when nitrogen inputs from weathering bedrock are accompanied by sufficient organic carbon concentrations to promote microbial nitrogen transformations.
Suggested Citation
Holloway, J., and Smith, R.L., 2005, Nitrogen and carbon flow from rock to water: Regulation through soil biogeochemical processes, Mokelumne River watershed, California, and Grand Valley, Colorado: Journal of Geophysical Research F: Earth Surface, v. 110, no. 1, F01010, https://doi.org/10.1029/2004JF000124.
| Publication type | Article |
|---|---|
| Publication Subtype | Journal Article |
| Title | Nitrogen and carbon flow from rock to water: Regulation through soil biogeochemical processes, Mokelumne River watershed, California, and Grand Valley, Colorado |
| Series title | Journal of Geophysical Research F: Earth Surface |
| DOI | 10.1029/2004JF000124 |
| Volume | 110 |
| Issue | 1 |
| Publication Date | February 22, 2005 |
| Year Published | 2005 |
| Language | English |
| Publisher | AGU |
| Contributing office(s) | Toxic Substances Hydrology Program |
| Description | F01010 |