Peer-Reviewed Journal Details
Mandatory Fields
Barrett, M,Khalil, MI,Jahangir, MMR,Lee, C,Cardenas, LM,Collins, G,Richards, KG,O'Flaherty, V
2016
April
Environmental Science And Pollution Research
Carbon amendment and soil depth affect the distribution and abundance of denitrifiers in agricultural soils
Published
WOS: 12 ()
Optional Fields
Denitrification nirK nirS nosZ Subsoil N2O/N-2 emissions REAL-TIME PCR MICROBIAL COMMUNITY STRUCTURE NITROUS-OXIDE PRODUCTION REDUCTASE GENES NIRK NOSZ GENES ENVIRONMENTAL-SAMPLES INCUBATION TECHNIQUE FOREST ECOSYSTEMS ENZYME-ACTIVITY ORGANIC-CARBON
23
7899
7910
The nitrite reductase (nirS and nirK) and nitrous oxide reductase-encoding (nosZ) genes of denitrifying populations present in an agricultural grassland soil were quantified using real-time polymerase chain reaction (PCR) assays. Samples from three separate pedological depths at the chosen site were investigated: horizon A (0-10 cm), horizon B (45-55 cm), and horizon C (120-130 cm). The effect of carbon addition (treatment 1, control; treatment 2, glucose-C; treatment 3, dissolved organic carbon (DOC)) on denitrifier gene abundance and N2O and N-2 fluxes was determined. In general, denitrifier abundance correlated well with flux measurements; nirS was positively correlated with N2O, and nosZ was positively correlated with N-2 (P < 0.03). Denitrifier gene copy concentrations per gram of soil (GCC) varied in response to carbon type amendment (P < 0.01). Denitrifier GCCs were high (ca. 10(7)) and the bac:nirK, bac:nirS, bac:nir (T) , and bac:nosZ ratios were low (ca. 10(-1)/10) in horizon A in all three respective treatments. Glucose-C amendment favored partial denitrification, resulting in higher nir abundance and higher N2O fluxes compared to the control. DOC amendment, by contrast, resulted in relatively higher nosZ abundance and N-2 emissions, thus favoring complete denitrification. We also noted soil depth directly affected bacterial, archaeal, and denitrifier abundance, possibly due to changes in soil carbon availability with depth.
10.1007/s11356-015-6030-1
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