Improving in situ recovery of soil nitrogen using the microdialysis technique

Buckley, Scott, Brackin, Richard, Nasholm, Torgny, Schmidt, Susanne and Jamtgard, Sandra (2017) Improving in situ recovery of soil nitrogen using the microdialysis technique. Soil Biology and Biochemistry, 114 93-103. doi:10.1016/j.soilbio.2017.07.009

Author Buckley, Scott
Brackin, Richard
Nasholm, Torgny
Schmidt, Susanne
Jamtgard, Sandra
Title Improving in situ recovery of soil nitrogen using the microdialysis technique
Formatted title
Improving in situ recovery of soil nitrogen using the microdialysis technique
Journal name Soil Biology and Biochemistry   Check publisher's open access policy
ISSN 0038-0717
Publication date 2017-11-01
Sub-type Article (original research)
DOI 10.1016/j.soilbio.2017.07.009
Open Access Status Not yet assessed
Volume 114
Start page 93
End page 103
Total pages 11
Place of publication Kidlington, Oxford, United Kingdom
Publisher Pergamon Press
Language eng
Formatted abstract
Microdialysis is a technique that can be used to sample fluxes of nitrogen (N) in soils with minimal disturbance. To advance our understanding of the technique and improve N recovery, we compared a common membrane type (10 × 0.5 mm probe length and width, 20 kDa molecular weight cut-off; MWCO) with alternative length and MWCO configurations (30 mm; and 100 kDa MWCO). We hypothesised that the alternative membranes would improve recovery of low molecular weight N via increased surface area and membrane pore size. The test environments, sampled at fixed pump flow rates, were: (i) stirred 100 μM N standard solution containing organic (amino acid) and inorganic (ammonium, nitrate) N; (ii) soil spiked with 100 μM standard N solution; and (iii) in situ boreal forest soil. In general, long membranes recovered more N, but the magnitude of improved recovery varied with test environment. Long membranes recovered more inorganic N regardless of flow rate, except ammonium in stirred solution, where length had no effect at slow flow rates. Long membranes also recovered more organic N from stirred solution regardless of flow rate, and recovered most N at slow flow rates in spiked soil. Longer membranes recovered more amino acids in situ in forest soil, with improved resolution of individual amino acids, but were biased towards soluble, mobile forms. MWCO did not affect N recoveries, indicating that in the test conditions, membrane length had greater control than pore size. We discuss the bottlenecks of microdialysis application in soil research and conclude that optimised membrane configurations will advance its use as a tool for quantifying nutrient fluxes in soils.
Keyword Amino acids
Inorganic N
N flux
Organic nitrogen
Soil nitrogen availability
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
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School of Agriculture and Food Sciences
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Created: Thu, 17 Aug 2017, 11:27:31 EST by Richard Brackin on behalf of Learning and Research Services (UQ Library)