Organic matter contributions to nitrous oxide emissions following nitrate addition are not proportional to substrate-induced soil carbon priming.

Autor: Li Y; Department of Soil and Physical Sciences, PO Box 85084, Lincoln University, Lincoln 7647, New Zealand; Manaaki Whenua - Landcare Research, PO Box 69040, Lincoln 7640, New Zealand. Electronic address: yuanli@lzu.edu.cn., Moinet GYK; Manaaki Whenua - Landcare Research, PO Box 69040, Lincoln 7640, New Zealand., Clough TJ; Department of Soil and Physical Sciences, PO Box 85084, Lincoln University, Lincoln 7647, New Zealand., Whitehead D; Manaaki Whenua - Landcare Research, PO Box 69040, Lincoln 7640, New Zealand.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2022 Dec 10; Vol. 851 (Pt 2), pp. 158274. Date of Electronic Publication: 2022 Aug 27.
DOI: 10.1016/j.scitotenv.2022.158274
Abstrakt: The addition of carbon (C) substrate often modifies the rate of soil organic matter (SOM) decomposition. This is known as the priming effect. Nitrous oxide (N 2 O) emissions from soil are also linked to C substrate dynamics; however, the relationship between the priming effect and N 2 O emissions from soil is not understood. This study aimed to investigate the effects of C and N substrate addition on the linkages between SOM priming and N 2 O emissions. We applied 13 C-labelled substrates (acetate, butyrate, glucose; 80 μg C g -1 ), with water as a control, and 15 N-labelled N (300 μg N g -1 soil, potassium nitrate) to three different soils, and, after 3 days, we measured the effects on the priming of SOM and sources of N 2 O emission. Carbon substrate addition increased both CO 2 - and SOM-derived N 2 O emissions in the presence of exogenous N. Emissions of CO 2 and N 2 O from soils with added glucose (mean ± standard deviation, 0.73 ± 0.13 μmol m -2 s -1 and 21.4 ± 12.1 mg N m -2 h -1 ) were higher (p < 0.05) than those from soils treated with acetate (0.64 ± 0.11 μmol m -2 s -1 and 10.9 ± 6.5 mg N m -2 h -1 ) or butyrate (0.61 ± 0.11 μmol m -2 s -1 and 11.0 ± 6.6 mg N m -2 h -1 ), respectively. Acetate addition induced a stronger (p < 0.05) priming effect on soil C (0.07 ± 0.09 μmol C m -2 s -1 ) than that for glucose (0.02 ± 0.10 μmol C m -2 s -1 ), while butyrate addition resulted in negative priming (-0.09 ± 0.05 μmol C m -2 s -1 ). SOM-derived N 2 O emissions were relatively low from soils with butyrate addition (1.4 ± 1.5 mg N m -2 h -1 ) compared with acetate (2.9 ± 2.3 mg N m -2 h -1 ) or glucose (9.2 ± 4.5 mg N m -2 h -1 ). There was no clear relationship between the priming effect and SOM-derived N 2 O emissions. The observed priming effect related to the potential electron donor supply of the C substrates was not observed. There is a need to further examine the role of soil priming in relation to soil N 2 O emissions.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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Databáze: MEDLINE
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