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Updated: Jul 2, 2026
09:19
Utilizing Soil Density Fractionation to Separate Distinct Soil Carbon Pools
Published on: December 16, 2022
Macroaggregates dominate colloidal phosphorus sequestration in Ultisol paddies: Evidence from size-fractionation
Jiamin Zhang1, Zhuoling Liu1, Yanling Wang1
1School of Ecology and Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing, China.
Journal of Environmental Quality
|July 1, 2026
Summary
Soil macroaggregates (MAC) are key for sequestering colloidal phosphorus (Pcoll), outperforming microaggregates (MIC). Enhancing MAC through soil management can improve phosphorus cycling and reduce losses in agricultural systems.
Area of Science:
- Soil Science
- Environmental Chemistry
- Agricultural Science
Background:
- Soil aggregates are crucial for colloidal phosphorus (Pcoll) dynamics, impacting nutrient cycling and P loss.
- Understanding Pcoll mechanisms within macroaggregates (MAC) and microaggregates (MIC) is vital, especially in Ultisols.
- Current knowledge on Pcoll distribution and behavior across aggregate fractions is limited.
Purpose of the Study:
- To investigate Pcoll release, content, and colloidal properties across aggregate fractions (MAC vs. MIC) in Ultisols.
- To determine how slope position, soil depth, and cultivation history influence Pcoll dynamics.
- To elucidate the role of MAC and MIC in colloidal phosphorus sequestration and mobility.
Main Methods:
- Systematic analysis of Pcoll release via water-dispersible colloids (Crq).
- Quantification of Pcoll content and assessment of colloidal surface morphology using scanning electron microscopy.
- Evaluation of colloidal stability and mobility through dynamic dispersion experiments.
Main Results:
- Pcoll and Crq concentrations significantly increased with soil depth.
- Macroaggregates (MAC) consistently showed higher Pcoll retention than microaggregates (MIC).
- Distinct colloidal structures were observed: MAC with loosely bound particles, MIC with compact layers; MAC demonstrated greater Pcoll immobilization capacity.
Conclusions:
- Macroaggregates (MAC) play a dominant role in colloidal phosphorus (Pcoll) sequestration.
- Soil depth and aggregation influence Pcoll distribution and mobility.
- Management strategies like organic amendments and reduced tillage can enhance MAC, promoting sustainable phosphorus management in agricultural systems.
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