Organic carbon availability limiting microbial denitrification in the deep vadose zone

Biodegradation in the Vadose Zone

Denitrification and availability of carbon and nitrogen in a well-drained pasture soil amended with particulate organic carbon.

A well-drained soil in N-fertilized dairy pasture was amended with particulate organic carbon (POC), either sawdust or coarse woody mulch, and sampled every 4 wk for a year to test the hypothesis that the addition of POC would increase denitrification activity by increasing the number of microsites where denitrification occurred. Overall mean denitrifying enzyme activity (DEA), on a gravimetric...

Is Available Carbon Limiting Microbial Respiration in the Rhizosphere?

It is widely known that the carbon availability in the rhizosphere is much higher than in the bulk soil. However, studies have failed to show whether microbial respiration in the rhizosphere is carbon-limited. Precise and timely measurements are lacking. We measured carbon availability index (basal respiration divided by substrate-induced respiration), and water soluble carbon in soils sampled ...

Deep Vadose Zone Characterization at the Hanford Site: Accomplishments from the Last Ten Years

The overall goal of the Tank Farm Vadose Zone Project, led by CH2M HILL Hanford Group, Inc., is to define risks from past and future single-shell tank farm activities at Hanford. To meet this goal, CH2M HILL Hanford Group, Inc. tasked scientists from Pacific Northwest National Laboratory (PNNL) to perform detailed analyses on vadose zone sediments collected within/adjacent to the twelve single-...

Availability of phosphate and labile organic carbon

Biogeosciences Discussions is the access reviewed discussion forum of Biogeosciences Availability of phosphate for phytoplankton and bacteria and of labile organic carbon for bacteria at different pCO2 levels in a mesocosm study T. Tanaka, T. F. Thingstad, T. Løvdal, H.-P. Grossart, A. Larsen, K. G. Schulz, and U. Riebesell Marine Microbiology Res. Group (MMRG), Dept. of Biology, Univ. Bergen, ...