Journal article

Publication year: 2008

Pages: 285-291

Journal: European Journal of Soil Science

Volume number: 59

Issue number: 2

ISSN: 1351-0754

eISSN: 1365-2389

DOI Link: https://doi.org/10.1111/j.1365-2389.2007.00995.x

Publisher: Wiley

Abstract: 
The contribution of bacteria and fungi to NH4+ and organic N (N-org) oxidation was determined in a grassland soil (pH 6.3) by using the general bacterial inhibitor streptomycin or the fungal inhibitor cycloheximide in a laboratory incubation study at 20 degrees C. Each inhibitor was applied at a rate of 3 mg g(-1) oven-dry soil. The size and enrichment of the mineral N pools from differentially ((NH4NO3)-N-15 and (NH4NO3)-N-15) and doubly labelled ((NH4NO3)-N-15-N-15) NH4NO3 were measured at 3, 6, 12, 24, 48, 72, 96 and 120 hours after N addition. Labelled N was applied to each treatment, to supply NH4+-N and NO3--N at 3.15 mu mol N g(-1) oven-dry soil. The N treatments were enriched to 60 atom % excess in N-15 and acetate was added at 100 mu mol C g(-1) oven-dry soil, to provide a readily available carbon source. The oxidation rates of NH4+ and N-org were analysed separately for each inhibitor treatment with a N-15 tracing model. In the absence of inhibitors, the rates of NH4+ oxidation and organic N oxidation were 0.0045 mu mol N g(-1) hour(-1) and 0.0023 mu mol N g(-1) hour(-1), respectively. Streptomycin had no effect on nitrification but cycloheximide inhibited the oxidation of NH4+ by 89% and the oxidation of organic N by more than 30%. The current study provides evidence to suggest that nitrification in grassland soil is carried out by fungi and that they can simultaneously oxidize NH4+ and organic N.

Harvard Citation style: Laughlin, R., Stevens, R., Müller, C. and Watson, C. (2008) Evidence that fungi can oxidize NH4+ to NO3- in a grassland soil, European Journal of Soil Science, 59(2), pp. 285-291. https://doi.org/10.1111/j.1365-2389.2007.00995.x

APA Citation style: Laughlin, R., Stevens, R., Müller, C., & Watson, C. (2008). Evidence that fungi can oxidize NH4+ to NO3- in a grassland soil. European Journal of Soil Science. 59(2), 285-291. https://doi.org/10.1111/j.1365-2389.2007.00995.x