Details
| Original language | English |
|---|---|
| Pages (from-to) | 31-54 |
| Number of pages | 24 |
| Journal | Biogeochemistry |
| Volume | 143 |
| Issue number | 1 |
| Early online date | 8 Feb 2019 |
| Publication status | Published - 15 Mar 2019 |
Abstract
Submerged rice cultivation is characterized by redox fluctuations and results in the formation of paddy soils, often accompanied by soil organic carbon (SOC) accumulation. The impact of redox fluctuations and the underlying soil type on the fate of organic carbon (OC) in paddy soils are unknown. Hence, we mimicked paddy soil development in the laboratory by exposing two soil types with contrasting mineral assemblages (Alisol and Andosol) to eight anoxic–oxic cycles over 1 year. Soils regularly received 13 C-labeled rice straw. As control we used a second set of samples without straw addition as well as samples under static oxic conditions with and without straw. Headspaces were analyzed for carbon dioxide and methane as well as their δ 13 C signatures, whereas soil solutions were analyzed for redox potential, pH, dissolved iron, and dissolved organic carbon (DOC and DO 13 C). At the end of the experiment, when eight redox cycles were completed, mineral-associated organic matter (MOM) was isolated by density fractionation and characterized for δ 13 C, non-cellulosic carbohydrates, and lignin-derived phenols. Moreover, changes in the soil’s microbial community structure were measured. For both soil types, headspace data confirmed less respiration in straw-amended soils with redox fluctuation than in those under static oxic conditions. The δ 13 C data revealed that, irrespective of soil type, straw carbon allocation into MOM was larger in soils with redox fluctuation than in those with static oxic conditions. A net increase in MOM after the one-year incubation, however, was only observed in the respective Andosol, probably due to abundant reactive minerals capable of OC uptake. In the Alisol, straw OC most likely exchanged initial MOM. A potential for lignin accumulation in the MOM of soils incubated with straw and redox fluctuation was observed for both soil types. Lignin and carbohydrates suggest a plant origin of MOM formed under redox fluctuation. The initially similar bacterial community composition of the Alisol and Andosol changed differently under redox fluctuation. The stronger change in the Alisol indicates less protective microbial habitats. In summary, the overall turnover of straw OC in soils under redox fluctuation seems to be independent of soil type, while net accumulation of SOC as well as the evolution of the bacterial community structure may in part depend on soil type, suggesting an impact of the soil’s mineral composition.
Keywords
- Microbial community, Mineral-associated organic matter, Mineralization, Paddy soils, Redox fluctuation, Soil organic matter formation
ASJC Scopus subject areas
- Environmental Science(all)
- Environmental Chemistry
- Environmental Science(all)
- Water Science and Technology
- Earth and Planetary Sciences(all)
- Earth-Surface Processes
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In: Biogeochemistry, Vol. 143, No. 1, 15.03.2019, p. 31-54.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Tracing organic carbon and microbial community structure in mineralogically different soils exposed to redox fluctuations
AU - Winkler, Pauline
AU - Kaiser, Klaus
AU - Jahn, Reinhold
AU - Mikutta, Robert
AU - Fiedler, Sabine
AU - Cerli, Chiara
AU - Kölbl, Angelika
AU - Schulz, Stefanie
AU - Jankowska, Martha
AU - Schloter, Michael
AU - Müller-Niggemann, Cornelia
AU - Schwark, Lorenz
AU - Woche, Susanne K.
AU - Kümmel, Steffen
AU - Utami, Sri R.
AU - Kalbitz, Karsten
N1 - Funding information: The study was funded by Deutsche Forschungsgemeinschaft—DFG within the research unit FOR995 Biogeochemistry of Paddy Soil Evolution (Grants FI 803/8-1; JA 523/16-1; KA 1737/10-1; SCHL 446/7-1; SCHW 554/20-1,2; KO 1035/35-1,2) initiated by Ingrid Kögel-Knabner. The authors declare that there are no conflicts of interest. We gratefully acknowledge the support of Jorin Schoorl, Susanne Horka, Alexandra Boritzki, Christine Krenkewitz, Gudrun von Koch, Simal Dhimal, Heike Maennicke, Marianne Benesch, Bruno Glaser, Gisle Vestergaard, Gabi Albert, and Madina Burkitbayeva during laboratory work and data analyses.
PY - 2019/3/15
Y1 - 2019/3/15
N2 - Submerged rice cultivation is characterized by redox fluctuations and results in the formation of paddy soils, often accompanied by soil organic carbon (SOC) accumulation. The impact of redox fluctuations and the underlying soil type on the fate of organic carbon (OC) in paddy soils are unknown. Hence, we mimicked paddy soil development in the laboratory by exposing two soil types with contrasting mineral assemblages (Alisol and Andosol) to eight anoxic–oxic cycles over 1 year. Soils regularly received 13 C-labeled rice straw. As control we used a second set of samples without straw addition as well as samples under static oxic conditions with and without straw. Headspaces were analyzed for carbon dioxide and methane as well as their δ 13 C signatures, whereas soil solutions were analyzed for redox potential, pH, dissolved iron, and dissolved organic carbon (DOC and DO 13 C). At the end of the experiment, when eight redox cycles were completed, mineral-associated organic matter (MOM) was isolated by density fractionation and characterized for δ 13 C, non-cellulosic carbohydrates, and lignin-derived phenols. Moreover, changes in the soil’s microbial community structure were measured. For both soil types, headspace data confirmed less respiration in straw-amended soils with redox fluctuation than in those under static oxic conditions. The δ 13 C data revealed that, irrespective of soil type, straw carbon allocation into MOM was larger in soils with redox fluctuation than in those with static oxic conditions. A net increase in MOM after the one-year incubation, however, was only observed in the respective Andosol, probably due to abundant reactive minerals capable of OC uptake. In the Alisol, straw OC most likely exchanged initial MOM. A potential for lignin accumulation in the MOM of soils incubated with straw and redox fluctuation was observed for both soil types. Lignin and carbohydrates suggest a plant origin of MOM formed under redox fluctuation. The initially similar bacterial community composition of the Alisol and Andosol changed differently under redox fluctuation. The stronger change in the Alisol indicates less protective microbial habitats. In summary, the overall turnover of straw OC in soils under redox fluctuation seems to be independent of soil type, while net accumulation of SOC as well as the evolution of the bacterial community structure may in part depend on soil type, suggesting an impact of the soil’s mineral composition.
AB - Submerged rice cultivation is characterized by redox fluctuations and results in the formation of paddy soils, often accompanied by soil organic carbon (SOC) accumulation. The impact of redox fluctuations and the underlying soil type on the fate of organic carbon (OC) in paddy soils are unknown. Hence, we mimicked paddy soil development in the laboratory by exposing two soil types with contrasting mineral assemblages (Alisol and Andosol) to eight anoxic–oxic cycles over 1 year. Soils regularly received 13 C-labeled rice straw. As control we used a second set of samples without straw addition as well as samples under static oxic conditions with and without straw. Headspaces were analyzed for carbon dioxide and methane as well as their δ 13 C signatures, whereas soil solutions were analyzed for redox potential, pH, dissolved iron, and dissolved organic carbon (DOC and DO 13 C). At the end of the experiment, when eight redox cycles were completed, mineral-associated organic matter (MOM) was isolated by density fractionation and characterized for δ 13 C, non-cellulosic carbohydrates, and lignin-derived phenols. Moreover, changes in the soil’s microbial community structure were measured. For both soil types, headspace data confirmed less respiration in straw-amended soils with redox fluctuation than in those under static oxic conditions. The δ 13 C data revealed that, irrespective of soil type, straw carbon allocation into MOM was larger in soils with redox fluctuation than in those with static oxic conditions. A net increase in MOM after the one-year incubation, however, was only observed in the respective Andosol, probably due to abundant reactive minerals capable of OC uptake. In the Alisol, straw OC most likely exchanged initial MOM. A potential for lignin accumulation in the MOM of soils incubated with straw and redox fluctuation was observed for both soil types. Lignin and carbohydrates suggest a plant origin of MOM formed under redox fluctuation. The initially similar bacterial community composition of the Alisol and Andosol changed differently under redox fluctuation. The stronger change in the Alisol indicates less protective microbial habitats. In summary, the overall turnover of straw OC in soils under redox fluctuation seems to be independent of soil type, while net accumulation of SOC as well as the evolution of the bacterial community structure may in part depend on soil type, suggesting an impact of the soil’s mineral composition.
KW - Microbial community
KW - Mineral-associated organic matter
KW - Mineralization
KW - Paddy soils
KW - Redox fluctuation
KW - Soil organic matter formation
UR - http://www.scopus.com/inward/record.url?scp=85061336465&partnerID=8YFLogxK
U2 - 10.1007/s10533-019-00548-7
DO - 10.1007/s10533-019-00548-7
M3 - Article
AN - SCOPUS:85061336465
VL - 143
SP - 31
EP - 54
JO - Biogeochemistry
JF - Biogeochemistry
SN - 0168-2563
IS - 1
ER -