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Combined Size and Density Fractionation of Soils for Investigations of Organo-Mineral Interactions
Published on: February 15, 2019
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Lithological Controls on Soil Aggregates and Minerals Regulate Microbial Carbon Use Efficiency and Necromass
Peilei Hu1,2,3, Wei Zhang1,2,3, Andrew T Nottingham4,5
1Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China.
Environmental Science & Technology
|November 14, 2024
Summary
Bedrock type impacts soil carbon cycling. Karst soils reduce microbial carbon use efficiency (CUE) but enhance necromass stability, highlighting the need to balance these factors for soil carbon preservation.
Area of Science:
- Soil Science
- Microbial Ecology
- Biogeochemistry
Background:
- Microbial carbon use efficiency (CUE) and necromass stabilization are key to soil carbon formation and persistence.
- Soil aggregates and minerals influence CUE and necromass, but the role of parent material (lithology) is poorly understood.
Purpose of the Study:
- To investigate how bedrock lithology (karst vs. nonkarst) and soil geochemistry affect microbial CUE and necromass stabilization.
- To determine the influence of soil aggregation and mineralogy on these processes across a climatic gradient.
Main Methods:
- Quantified microbial CUE in bulk and crushed aggregates from karst and nonkarst soils.
- Assessed microbial necromass in bulk soils and mineral-associated organic matter.
- Analyzed soil geochemistry, including pH and iron (hydr)oxide content.
Main Results:
- Aggregate crushing increased microbial CUE in both soil types.
- Karst soils exhibited greater macroaggregate stability and lower CUE compared to nonkarst soils.
- Microbial CUE was negatively correlated with iron (hydr)oxides and higher pH in karst soils.
- Karst soils showed enhanced microbial necromass stability via organo-mineral associations.
Conclusions:
- Bedrock lithology significantly mediates the effects of soil aggregates and minerals on microbial CUE and necromass.
- Optimizing soil carbon preservation requires balancing the dual roles of minerals in reducing CUE and increasing necromass stability.
Keywords:
aggregatesiron (hydr)oxideslithologymicrobial life strategiesmicrobial necromassmineral protectionMore Related Videos
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