To shake or not to shake : Silicone tube approach for incubation studies on CH 4 oxidation in submerged soils
(2019) In Science of the Total Environment 657. p.893-901- Abstract
Incubation experiments are the most common approach to measure methane (CH 4 ) oxidation potential in soils from various ecosystems and land-use practices. However, the commonly used headspace CH 4 injection into microcosms and the shaking of the soil slurry during incubation fully removes CH 4 (soil-born) and O 2 (air-born) gradients common in situ, and may also induce various errors and disturbances. As an alternative, we propose CH ... (More)
Incubation experiments are the most common approach to measure methane (CH 4 ) oxidation potential in soils from various ecosystems and land-use practices. However, the commonly used headspace CH 4 injection into microcosms and the shaking of the soil slurry during incubation fully removes CH 4 (soil-born) and O 2 (air-born) gradients common in situ, and may also induce various errors and disturbances. As an alternative, we propose CH 4 input into microcosm soils via a silicone tube located within the slurry. We hypothesized that (i) poor CH 4 diffusion in slurry will be compensated by direct CH 4 delivery into the slurry via a silicone tube and, consequently, (ii) shaking of microcosms can be substituted with the soil silicone tube CH 4 injection. During a 29-day submerged paddy soil incubation, the highest net CH 4 oxidation rate was 1.6 μg C g −1 dry soil h −1 , measured between the 3rd and 7th day after injecting 13 CH 4 into the slurry via a silicone tube without shaking. This rate was 1.5–2.5 times faster than the respective CH 4 oxidation after headspace injection without shaking (1st hypothesis supported). As expected, shaking accelerated CH 4 oxidation regardless of injection methods by 3.2–3.7 times (most intensively on days 3–7) compared to headspace injection without shaking. Nonetheless, the rates were similar between silicone tube injection without shaking and headspace injection with shaking. This supports the hypothesized potential of silicone tubes to substitute the common shaking method (2nd hypothesis). Furthermore, shaking increased the incorporation of 13 C from CH 4 into soil organic matter and microbial biomass by 1.8–2.7 times compared with CH 4 injection into tubes and the static control without tubes. This reflects an overestimation of CH 4 oxidation due to shaking. We conclude that direct soil CH 4 injection via silicone tubes is advantageous in incubation experiments because gas concentration gradients are maintained and thereby more realistically reflect natural soil conditions.
(Less)
- author
- Fan, Lichao ; Shahbaz, Muhammad LU ; Ge, Tida ; Wu, Jinshui ; Kuzyakov, Yakov and Dorodnikov, Maxim
- publishing date
- 2019-03-20
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- C-CH, Methane oxidation, Paddy soil, Shaking, Silicone tube, Slurry
- in
- Science of the Total Environment
- volume
- 657
- pages
- 893 - 901
- publisher
- Elsevier
- external identifiers
-
- scopus:85058220476
- pmid:30677954
- ISSN
- 0048-9697
- DOI
- 10.1016/j.scitotenv.2018.12.090
- language
- English
- LU publication?
- no
- id
- 51f2c4f9-74d5-49b8-a9c6-ab150207918d
- date added to LUP
- 2019-10-23 12:44:04
- date last changed
- 2024-04-16 22:14:34
@article{51f2c4f9-74d5-49b8-a9c6-ab150207918d,
abstract = {{<p> Incubation experiments are the most common approach to measure methane (CH <sub>4</sub> ) oxidation potential in soils from various ecosystems and land-use practices. However, the commonly used headspace CH <sub>4</sub> injection into microcosms and the shaking of the soil slurry during incubation fully removes CH <sub>4</sub> (soil-born) and O <sub>2</sub> (air-born) gradients common in situ, and may also induce various errors and disturbances. As an alternative, we propose CH <sub>4</sub> input into microcosm soils via a silicone tube located within the slurry. We hypothesized that (i) poor CH <sub>4</sub> diffusion in slurry will be compensated by direct CH <sub>4</sub> delivery into the slurry via a silicone tube and, consequently, (ii) shaking of microcosms can be substituted with the soil silicone tube CH <sub>4</sub> injection. During a 29-day submerged paddy soil incubation, the highest net CH <sub>4</sub> oxidation rate was 1.6 μg C g <sup>−1</sup> dry soil h <sup>−1</sup> , measured between the 3rd and 7th day after injecting <sup>13</sup> CH <sub>4</sub> into the slurry via a silicone tube without shaking. This rate was 1.5–2.5 times faster than the respective CH <sub>4</sub> oxidation after headspace injection without shaking (1st hypothesis supported). As expected, shaking accelerated CH <sub>4</sub> oxidation regardless of injection methods by 3.2–3.7 times (most intensively on days 3–7) compared to headspace injection without shaking. Nonetheless, the rates were similar between silicone tube injection without shaking and headspace injection with shaking. This supports the hypothesized potential of silicone tubes to substitute the common shaking method (2nd hypothesis). Furthermore, shaking increased the incorporation of <sup>13</sup> C from CH <sub>4</sub> into soil organic matter and microbial biomass by 1.8–2.7 times compared with CH <sub>4</sub> injection into tubes and the static control without tubes. This reflects an overestimation of CH <sub>4</sub> oxidation due to shaking. We conclude that direct soil CH <sub>4</sub> injection via silicone tubes is advantageous in incubation experiments because gas concentration gradients are maintained and thereby more realistically reflect natural soil conditions. </p>}},
author = {{Fan, Lichao and Shahbaz, Muhammad and Ge, Tida and Wu, Jinshui and Kuzyakov, Yakov and Dorodnikov, Maxim}},
issn = {{0048-9697}},
keywords = {{C-CH; Methane oxidation; Paddy soil; Shaking; Silicone tube; Slurry}},
language = {{eng}},
month = {{03}},
pages = {{893--901}},
publisher = {{Elsevier}},
series = {{Science of the Total Environment}},
title = {{To shake or not to shake : Silicone tube approach for incubation studies on CH
<sub>4</sub>
oxidation in submerged soils}},
url = {{http://dx.doi.org/10.1016/j.scitotenv.2018.12.090}},
doi = {{10.1016/j.scitotenv.2018.12.090}},
volume = {{657}},
year = {{2019}},
}