TY - JOUR

T1 - Soil texture affects the coupling of litter decomposition and soil organic matter formation

AU - Angst, Gerrit

AU - Pokorný, Jan

AU - Mueller, Carsten W.

AU - Prater, Isabel

AU - Preusser, Sebastian

AU - Kandeler, Ellen

AU - Meador, Travis

AU - Straková, Petra

AU - Hájek, Tomáš

AU - van Buiten, Gerard

AU - Angst, Šárka

N1 - Funding Information: This study was funded by the Czech Ministry of Education, Youth, and Sport (grant numbers: LM2015075 and EF16_013/0001782 – SoWa Ecosystems Research), and the Czech Science Foundation (grant numbers 19-00533Y , 18-24138S , and 19-17139S ). The contribution of Ellen Kandeler and Sebastian Preusser was funded by the Deutsche Forschungsgemeinschaft - DFG ( KA 1590/11-2 ), and the contribution of Petra Straková by the Academy of Finland (project 319262). We thank Kateřina Lapáčková, Hana Turoňová, and Sabine Rudolph for help in the lab, and the editor and reviewers for constructive comments. Publisher Copyright: © 2021 Elsevier Ltd

PY - 2021/8

Y1 - 2021/8

N2 - Incomplete knowledge on the environmental factors linking litter decomposition and the formation of soil organic matter (SOM) hampers the sustainable management of soil as a carbon (C) sink. Here, we explored the effect of soil texture on the fate of C from decomposing litter (Indiangrass; Sorghastrum nutans (L.) Nash) and the concurrent formation of SOM in mineral soils of different textures (sand- and clay-rich) and forest floor material. We quantified the amount of litter C respired, C remaining in the litter, and litter C retained in the soil/forest floor in a 186-day incubation employing stable isotope analyses (13C). We complemented our isotopic approach with the extraction of microbial biomarkers from the litter and soils/forest floor material and spectroscopic studies into the compositional changes of the incubated materials. We found that soil texture affected both the decomposition of litter and the retention of litter-derived C in the soil. The soil rich in clay provided conditions favorable for a more efficient microbial utilization of the litter material (high pH and high C use efficiency) as compared to the sand-rich soil and the forest floor. This resulted in lower amounts of litter C respired as CO2 (25.0%, vs. 55.6 and 56.1% in clay vs. sand and forest floor material, respectively) and higher amounts of litter C retained in the clay-rich soil (12.6% vs. 3.5 and 5.3% in clay vs. sand and forest floor material, respectively). High contents of silt- and clay-sized mineral particles in the clay-rich soil likely resulted in the ability to stabilize litter C in aggregates and organo-mineral associations, perhaps as microbial residues. This ability was low in the sand-rich soil and virtually absent in the forest floor, where the recalcitrance of the litter and native SOM was probably more relevant, and a larger portion of litter C may have been retained in the soil as relatively untransformed plant compounds. We emphasize that litter decomposition, the formation of SOM, and soil texture are tightly linked, such that any differences in soil texture alter litter decomposition and SOM formation patterns for the same litter.

AB - Incomplete knowledge on the environmental factors linking litter decomposition and the formation of soil organic matter (SOM) hampers the sustainable management of soil as a carbon (C) sink. Here, we explored the effect of soil texture on the fate of C from decomposing litter (Indiangrass; Sorghastrum nutans (L.) Nash) and the concurrent formation of SOM in mineral soils of different textures (sand- and clay-rich) and forest floor material. We quantified the amount of litter C respired, C remaining in the litter, and litter C retained in the soil/forest floor in a 186-day incubation employing stable isotope analyses (13C). We complemented our isotopic approach with the extraction of microbial biomarkers from the litter and soils/forest floor material and spectroscopic studies into the compositional changes of the incubated materials. We found that soil texture affected both the decomposition of litter and the retention of litter-derived C in the soil. The soil rich in clay provided conditions favorable for a more efficient microbial utilization of the litter material (high pH and high C use efficiency) as compared to the sand-rich soil and the forest floor. This resulted in lower amounts of litter C respired as CO2 (25.0%, vs. 55.6 and 56.1% in clay vs. sand and forest floor material, respectively) and higher amounts of litter C retained in the clay-rich soil (12.6% vs. 3.5 and 5.3% in clay vs. sand and forest floor material, respectively). High contents of silt- and clay-sized mineral particles in the clay-rich soil likely resulted in the ability to stabilize litter C in aggregates and organo-mineral associations, perhaps as microbial residues. This ability was low in the sand-rich soil and virtually absent in the forest floor, where the recalcitrance of the litter and native SOM was probably more relevant, and a larger portion of litter C may have been retained in the soil as relatively untransformed plant compounds. We emphasize that litter decomposition, the formation of SOM, and soil texture are tightly linked, such that any differences in soil texture alter litter decomposition and SOM formation patterns for the same litter.

KW - C isotope

KW - C NMR

KW - C sequestration

KW - C use efficiency

KW - Heterotrophic respiration

KW - Microbial community

U2 - 10.1016/j.soilbio.2021.108302

DO - 10.1016/j.soilbio.2021.108302

M3 - Journal article

AN - SCOPUS:85107652627

VL - 159

JO - Soil Biology & Biochemistry

JF - Soil Biology & Biochemistry

SN - 0038-0717

M1 - 108302

ER -