Carbon amendment and soil depth affect the distribution and abundance of denitrifiers in agricultural soils

Barrett, M., Khalil, M.I., Jahangir, M.M.R., Lee, C., Cardenas, L.M., Collins, G., Richards, K.G. and O’Flaherty, V. (2016) Carbon amendment and soil depth affect the distribution and abundance of denitrifiers in agricultural soils. Environmental Science and Pollution Research, 23(8), pp. 7899-7910. (doi:10.1007/s11356-015-6030-1) (PMID:26762934)

Full text not currently available from Enlighten.

Abstract

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 N2 fluxes was determined. In general, denitrifier abundance correlated well with flux measurements; nirS was positively correlated with N2O, and nosZ was positively correlated with N2 (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. 107) 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 N2emissions, 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.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Collins, Dr Gavin
Authors: Barrett, M., Khalil, M.I., Jahangir, M.M.R., Lee, C., Cardenas, L.M., Collins, G., Richards, K.G., and O’Flaherty, V.
College/School:College of Science and Engineering > School of Engineering
Journal Name:Environmental Science and Pollution Research
Publisher:Springer-Verlag
ISSN:0944-1344
ISSN (Online):1614-7499
Published Online:14 January 2016

University Staff: Request a correction | Enlighten Editors: Update this record