Projekt SOIL-H-Relax: Quellung von interpartikulären Mikrogelen im Boden
Final Report Abstract
In this project phase, 1H-NMR relaxometry was combined for the first time with soil structural stability testing methods in order to understand the contribution of interparticulate hydrogel to soilwater interactions and soil structural stability. The results showed that interparticulate hydrogels significantly contribute to soil structural stability and soil-water interactions by changing the water mobility in the soil matrix together with the strength and quality of particle-particle interactions. In wet and water-saturated soils, this positive contribution predominantly depends on the viscosity of the interparticulate hydrogel and various polymer-clay interactions as function of soil solution composition, soil textural properties and external factors in terms of moisture dynamics and agricultural management practices. On the one hand, the higher the hydrogel viscosity between the soil particles the more stable becomes the soil structure in water-saturated and unsaturated soil. On the other hand, in the context of soil structural development and soil aggregation, the importance of the mutual interactions between swollen hydrogel structures and clay particles becomes evident. Here, interparticulate hydrogel can reduce the dispersive and plastic shearing effects of swollen clay particles by restricting their swelling and by their additionally bridging via polyvalent cations over large scales. These findings are especially important for the understanding of soil structural development and for taking appropriate and sustainable management measures to maintain the sustainability of natural and cultivated soil. The mechanistic model developed in this thesis depicts all essential processes affecting soil structural stability and shall serve as a basis for understanding the contribution of interparticulate hydrogel and SOM to soil structural stability.
Publications
- 2014. Soil-Water Interactions. Simpson, Myrna J., Simpson, Andre J. NMR Spectroscopy: A Versatile Tool for Environmental Research. Chichester, UK: John Wiley Sons, Ltd. 291-303
Schaumann, Gabriele Ellen, Bertmer, Marko
(See online at https://doi.org/10.1002/9780470034590.emrstm1343) - 2015. Characterization of wet aggregate stability of soils by 1H-NMR relaxometry. Magnetic Resonance in Chemistry. 53, 694-703
Buchmann, Christian, Meyer, Maximilian, Schaumann, Gabriele Ellen
(See online at https://doi.org/10.1002/mrc.4147) - 2015. Intrinsic and model polymer hydrogel-induced soil structural stability of a silty sand soil as affected by soil moisture dynamics. Soil and Tillage Research. 154 22-33
Buchmann, Christian, Bentz, Jonas, Schaumann, Gabriele Ellen
(See online at https://doi.org/10.1016/j.still.2015.06.014) - 2016. Effect of water entrapment by a hydrogel on the microstructural stability of artificial soils with various clay content. Plant and Soil. 414 (2): 181-198
Buchmann, Christian, Schaumann, Gabriele Ellen
(See online at https://doi.org/10.1007/s11104-016-3110-z) - 2017. Biohydrogel induced soil-water interactions: how to untangle the gel effect? A review. Journal of Plant Nutrition and Soil Science. 180 (2): 121-141
Brax, Mathilde, Buchmann, Christian, Schaumann, Gabriele Ellen
(See online at https://doi.org/10.1002/jpln.201600453) - 2018. Determination of quantitative pore-size distribution of soils with 1H NMR relaxometry. European Journal of Soil Science. 69 (3): 393-406
Meyer, Maximilian, Buchmann, Christian, Schaumann, Gabriele Ellen
(See online at https://doi.org/10.1111/ejss.12548) - 2018. The contribution of various organic matter fractions to soil-water interactions and structural stability of an agriculturally cultivated soil. Journal of Plant Nutrition and Soil Science. 181 (4): 586-599
Buchmann, Christian, Schaumann, Gabriele Ellen
(See online at https://doi.org/10.1002/jpln.201700437)
