Details
| Original language | English |
|---|---|
| Article number | 109184 |
| Number of pages | 10 |
| Journal | Agriculture, Ecosystems and Environment |
| Volume | 375 |
| Early online date | 30 Jul 2024 |
| Publication status | Published - 1 Nov 2024 |
Abstract
The persistence of carbon (C) in soils strongly depends on its biophysiochemical formation pathways. However, the contributions of physical, chemical and microbial processes to organic C accrual across various landscapes and climates remain unclear. In this study, we employed a combination of physical fractionation and biomarker analysis to investigate soil organic C subjected to microbial anabolism and protected by aggregates and free minerals in typical agricultural lands across a climatic gradient across eastern China. Results showed that the proportion of aggregate-protected C in total C decreased progressively from mid-temperate (62 %) to tropical regions (20 %), while free mineral-associated C increased from 24 % to 58 %. This suggests a shift from aggregate protection as the primary pathway for soil organic C formation in cooler climates to a mineralogical association in warmer climates. Compared to free minerals, the stronger C acquisition in aggregates was characterized by greater occluded mineral-associated C probably due to the enriched reactive minerals and cations. However, less microbial-derived C detected in aggregates than in free minerlas (especially in warmer climates) because of spatial isolation. The enhanced soil organic C preservation in paddy fields compared to adjacent uplands was attributed to the strengthened microaggregate formation and increased C sequestration capacity of free minerals induced by long-term flooding conditions. To enhance C storage in agricultural soils, it is crucial to adopt strategies such as improving aggregation, strengthening microbial anabolism in cooler regions, and incorporating calcium-enriched inorganic amendments in warmer climates.
Keywords
- Aggregate-protected C, Agricultural lands, Microbial residues, Mineral-associated C
ASJC Scopus subject areas
- Environmental Science(all)
- Ecology
- Agricultural and Biological Sciences(all)
- Animal Science and Zoology
- Agricultural and Biological Sciences(all)
- Agronomy and Crop Science
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In: Agriculture, Ecosystems and Environment, Vol. 375, 109184, 01.11.2024.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Shifts in organic carbon protection mechanism in agricultural soils across climatic gradients
AU - Ma, Chong
AU - Xia, Yinhang
AU - Rui, Yichao
AU - Gao, Wei
AU - Duan, Xun
AU - Qiao, Hang
AU - He, Xunyang
AU - Hu, Yajun
AU - Huang, Daoyou
AU - Wu, Jinshui
AU - Su, Yirong
AU - Guggenberger, Georg
AU - Chen, Xiangbi
N1 - Publisher Copyright: © 2024 Elsevier B.V.
PY - 2024/11/1
Y1 - 2024/11/1
N2 - The persistence of carbon (C) in soils strongly depends on its biophysiochemical formation pathways. However, the contributions of physical, chemical and microbial processes to organic C accrual across various landscapes and climates remain unclear. In this study, we employed a combination of physical fractionation and biomarker analysis to investigate soil organic C subjected to microbial anabolism and protected by aggregates and free minerals in typical agricultural lands across a climatic gradient across eastern China. Results showed that the proportion of aggregate-protected C in total C decreased progressively from mid-temperate (62 %) to tropical regions (20 %), while free mineral-associated C increased from 24 % to 58 %. This suggests a shift from aggregate protection as the primary pathway for soil organic C formation in cooler climates to a mineralogical association in warmer climates. Compared to free minerals, the stronger C acquisition in aggregates was characterized by greater occluded mineral-associated C probably due to the enriched reactive minerals and cations. However, less microbial-derived C detected in aggregates than in free minerlas (especially in warmer climates) because of spatial isolation. The enhanced soil organic C preservation in paddy fields compared to adjacent uplands was attributed to the strengthened microaggregate formation and increased C sequestration capacity of free minerals induced by long-term flooding conditions. To enhance C storage in agricultural soils, it is crucial to adopt strategies such as improving aggregation, strengthening microbial anabolism in cooler regions, and incorporating calcium-enriched inorganic amendments in warmer climates.
AB - The persistence of carbon (C) in soils strongly depends on its biophysiochemical formation pathways. However, the contributions of physical, chemical and microbial processes to organic C accrual across various landscapes and climates remain unclear. In this study, we employed a combination of physical fractionation and biomarker analysis to investigate soil organic C subjected to microbial anabolism and protected by aggregates and free minerals in typical agricultural lands across a climatic gradient across eastern China. Results showed that the proportion of aggregate-protected C in total C decreased progressively from mid-temperate (62 %) to tropical regions (20 %), while free mineral-associated C increased from 24 % to 58 %. This suggests a shift from aggregate protection as the primary pathway for soil organic C formation in cooler climates to a mineralogical association in warmer climates. Compared to free minerals, the stronger C acquisition in aggregates was characterized by greater occluded mineral-associated C probably due to the enriched reactive minerals and cations. However, less microbial-derived C detected in aggregates than in free minerlas (especially in warmer climates) because of spatial isolation. The enhanced soil organic C preservation in paddy fields compared to adjacent uplands was attributed to the strengthened microaggregate formation and increased C sequestration capacity of free minerals induced by long-term flooding conditions. To enhance C storage in agricultural soils, it is crucial to adopt strategies such as improving aggregation, strengthening microbial anabolism in cooler regions, and incorporating calcium-enriched inorganic amendments in warmer climates.
KW - Aggregate-protected C
KW - Agricultural lands
KW - Microbial residues
KW - Mineral-associated C
UR - http://www.scopus.com/inward/record.url?scp=85199759607&partnerID=8YFLogxK
U2 - 10.1016/j.agee.2024.109184
DO - 10.1016/j.agee.2024.109184
M3 - Article
AN - SCOPUS:85199759607
VL - 375
JO - Agriculture, Ecosystems and Environment
JF - Agriculture, Ecosystems and Environment
SN - 0167-8809
M1 - 109184
ER -