Details
| Originalsprache | Englisch |
|---|---|
| Seiten (von - bis) | 14133-14145 |
| Seitenumfang | 13 |
| Fachzeitschrift | Environmental Science and Technology |
| Jahrgang | 56 |
| Ausgabenummer | 19 |
| Frühes Online-Datum | 15 Sept. 2022 |
| Publikationsstatus | Veröffentlicht - 4 Okt. 2022 |
Abstract
Colloidal organo-mineral associations contribute to soil organic matter (OM) preservation and mainly occur in two forms: (i) as water-dispersible colloids that are potentially mobile (free colloids) and (ii) as building units of soil microaggregates that are occluded inside them (occluded colloids). However, the way in which these two colloidal forms differ in terms of textural characteristics and chemical composition, together with the nature of their associated OM, remains unknown. To fill these knowledge gaps, free and occluded fine colloids <220 nm were isolated from arable soils with comparable organic carbon (Corg) but different clay contents. Free colloids were dispersed in water suspensions during wet-sieving, while occluded colloids were released from water-stable aggregates by sonication. The asymmetric flow field-flow fractionation analysis on the free and occluded colloids suggested that most of the 0.6-220 nm fine colloidal Corgwas present in size fractions that showed high abundances of Si, Al, and Fe. The pyrolysis-field ionization mass spectrometry revealed that the free colloids were relatively rich in less decomposed plant-derived OM (i.e., lipids, suberin, and free fatty acids), whereas the occluded colloids generally contained more decomposed and microbial-derived OM (i.e., carbohydrates and amides). In addition, a higher thermal stability of OM in occluded colloids pointed to a higher resistance to further degradation and mineralization of OM in occluded colloids than that in free colloids. This study provides new insights into the characteristics of subsized fractions of fine colloidal organo-mineral associations in soils and explores the impacts of free versus occluded colloidal forms on the composition and stability of colloid-associated OM.
ASJC Scopus Sachgebiete
- Chemie (insg.)
- Umweltwissenschaften (insg.)
- Umweltchemie
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in: Environmental Science and Technology, Jahrgang 56, Nr. 19, 04.10.2022, S. 14133-14145.
Publikation: Beitrag in Fachzeitschrift › Artikel › Forschung › Peer-Review
}
TY - JOUR
T1 - Implications of Free and Occluded Fine Colloids for Organic Matter Preservation in Arable Soils
AU - Tang, Ni
AU - Siebers, Nina
AU - Leinweber, Peter
AU - Eckhardt, Kai Uwe
AU - Dultz, Stefan
AU - Nischwitz, Volker
AU - Klumpp, Erwin
N1 - Funding Information: This work is associated with the MAD Soil project (MAD Soil - Microaggregates: Formation and turnover of the structural building blocks of soils), which is funded by the DFG (Deutsche Forschungsgemeinschaft, Research Unit 2179). N.T. would like to thank the China Scholarship Council (No. 201806190224) for supporting her studies at Forschungszentrum Jülich and RWTH Aachen University. The C and N determination by Jennifer Pelikan, ZEA-3, Forschungszentrum Jülich, and the ICP-OES measurements by Sabrina Tückhardt, ZEA-3, Forschungszentrum Jülich are gratefully acknowledged.
PY - 2022/10/4
Y1 - 2022/10/4
N2 - Colloidal organo-mineral associations contribute to soil organic matter (OM) preservation and mainly occur in two forms: (i) as water-dispersible colloids that are potentially mobile (free colloids) and (ii) as building units of soil microaggregates that are occluded inside them (occluded colloids). However, the way in which these two colloidal forms differ in terms of textural characteristics and chemical composition, together with the nature of their associated OM, remains unknown. To fill these knowledge gaps, free and occluded fine colloids <220 nm were isolated from arable soils with comparable organic carbon (Corg) but different clay contents. Free colloids were dispersed in water suspensions during wet-sieving, while occluded colloids were released from water-stable aggregates by sonication. The asymmetric flow field-flow fractionation analysis on the free and occluded colloids suggested that most of the 0.6-220 nm fine colloidal Corgwas present in size fractions that showed high abundances of Si, Al, and Fe. The pyrolysis-field ionization mass spectrometry revealed that the free colloids were relatively rich in less decomposed plant-derived OM (i.e., lipids, suberin, and free fatty acids), whereas the occluded colloids generally contained more decomposed and microbial-derived OM (i.e., carbohydrates and amides). In addition, a higher thermal stability of OM in occluded colloids pointed to a higher resistance to further degradation and mineralization of OM in occluded colloids than that in free colloids. This study provides new insights into the characteristics of subsized fractions of fine colloidal organo-mineral associations in soils and explores the impacts of free versus occluded colloidal forms on the composition and stability of colloid-associated OM.
AB - Colloidal organo-mineral associations contribute to soil organic matter (OM) preservation and mainly occur in two forms: (i) as water-dispersible colloids that are potentially mobile (free colloids) and (ii) as building units of soil microaggregates that are occluded inside them (occluded colloids). However, the way in which these two colloidal forms differ in terms of textural characteristics and chemical composition, together with the nature of their associated OM, remains unknown. To fill these knowledge gaps, free and occluded fine colloids <220 nm were isolated from arable soils with comparable organic carbon (Corg) but different clay contents. Free colloids were dispersed in water suspensions during wet-sieving, while occluded colloids were released from water-stable aggregates by sonication. The asymmetric flow field-flow fractionation analysis on the free and occluded colloids suggested that most of the 0.6-220 nm fine colloidal Corgwas present in size fractions that showed high abundances of Si, Al, and Fe. The pyrolysis-field ionization mass spectrometry revealed that the free colloids were relatively rich in less decomposed plant-derived OM (i.e., lipids, suberin, and free fatty acids), whereas the occluded colloids generally contained more decomposed and microbial-derived OM (i.e., carbohydrates and amides). In addition, a higher thermal stability of OM in occluded colloids pointed to a higher resistance to further degradation and mineralization of OM in occluded colloids than that in free colloids. This study provides new insights into the characteristics of subsized fractions of fine colloidal organo-mineral associations in soils and explores the impacts of free versus occluded colloidal forms on the composition and stability of colloid-associated OM.
KW - asymmetric flow field-flow fractionation
KW - colloidal organo-mineral associations
KW - mass spectrometry
KW - organic matter composition
KW - organic matter stability
KW - soil microaggregates
UR - http://www.scopus.com/inward/record.url?scp=85138788493&partnerID=8YFLogxK
U2 - 10.1021/acs.est.2c01973
DO - 10.1021/acs.est.2c01973
M3 - Article
C2 - 36108131
AN - SCOPUS:85138788493
VL - 56
SP - 14133
EP - 14145
JO - Environmental Science and Technology
JF - Environmental Science and Technology
SN - 0013-936X
IS - 19
ER -