Journal
PLANT AND SOIL
Volume 414, Issue 1-2, Pages 181-198Publisher
SPRINGER
DOI: 10.1007/s11104-016-3110-z
Keywords
NMR relaxometry; Hydrogel swelling; Rheology; Soil microstructure; Soil stability
Categories
Funding
- German Research Foundation, DFG [SCHA 849/5]
Ask authors/readers for more resources
Background and aims Interactions between soil constituents define soil microstructural stability and are enhanced by swellable organic substances (hydrogels) such as extracellular polymeric substances (EPS), root mucilage or synthetic polymers. This study aims to identify the still largely unknown mechanisms behind hydrogel-induced soil microstructural stability. We hypothesized that soil microstructural stability increased with increasing limitation of hydrogel swelling between soil particles. Methods One- and two-dimensional H-1 proton nuclear magnetic resonance relaxometry (H-1-NMR relaxometry) measurements were performed with untreated and polyacrylic-acid (PAA) treated artificial soils at various clay content and PAA concentrations. The results on the water distribution and water mobility in the artificial soils were related to their microstructural stability as measured by rheology. Results PAA treatment significantly increased soil microstructural stability up to five times, especially at high clay content. Soil microstructural stability increased with decreasing rotational mobility of water in the PAA-treated artificial. At the two highest PAA concentrations, the microstructural stability was the highest, although the mobility of water molecules was not further restricted. Conclusion In artificial soils, the viscosity of hydrogel structures between mineral particles and the additional formation of an external network by polymer-clay interactions such as polyvalent cation bridging seem to promote microstructural stability.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available