Barrientos-Sanhueza Cesar, Cargnino-Cisternas Danny, Díaz-Barrera Alvaro, Cuneo Italo F
Facultad de Ciencias Agronómicas y de los Alimentos, Pontificia Universidad Católica de Valparaíso, Valparaíso 2340025, Chile.
Escuela de Ingeniería Bioquímica, Pontificia Universidad Católica de Valparaíso, Valparaíso 2340025, Chile.
Polymers (Basel). 2022 Feb 25;14(5):922. doi: 10.3390/polym14050922.
Agricultural systems are facing the negative impacts of erosion and water scarcity, directly impacting the hydro-mechanical behavior of soil aggregation. Several technologies have been proposed to reduce hydro-mechanical soil-related problems in agriculture. Biopolymer-based hydrogels have been reported to be a great tool to tackle these problems in soils. In this study, we investigated the hydro-mechanical behavior of different soils media treated with Ca-bacterial alginate hydrogel. We used an unconfined uniaxial compression test, aggregate stability test and hydraulic conductivity measurements to investigate the mechanical and hydraulic behavior of treated soils media. Our results from unconfined uniaxial compression test showed that yield stress (i.e., strength) increased in treated soils with higher kaolinite and water content (i.e., HCM3), compared with untreated coarse quartz sand (i.e., CM1). Furthermore, we found that temperature is an important factor in the gelation capacity of our hydrogel. At room temperature, HCM3 displayed the higher aggregate stability, almost 5.5-fold compared with treated coarse quartz sand (HCM1), while this differential response was not sustained at warm temperature. In general, the addition of different quantities of kaolinite decreased the saturated hydraulic conductivity for all treatments. Finally, bright field microscopy imaging represents the soil media matrix between sand and clay particles with Ca-bacterial alginate hydrogel that modify the hydro-mechanical behavior of different soils media. The results of this study could be helpful for the soil-related problems in agriculture facing the negative effects of climate change.
农业系统正面临着侵蚀和水资源短缺的负面影响，这直接影响了土壤团聚体的水力-力学行为。人们已经提出了几种技术来减少农业中与土壤水力-力学相关的问题。据报道，基于生物聚合物的水凝胶是解决土壤中这些问题的一个很好的工具。在本研究中，我们研究了用钙-细菌藻酸盐水凝胶处理的不同土壤介质的水力-力学行为。我们使用无侧限单轴压缩试验、团聚体稳定性试验和水力传导率测量来研究处理后土壤介质的力学和水力行为。我们无侧限单轴压缩试验的结果表明，与未处理的粗石英砂（即CM1）相比，高岭石含量较高且含水量较高的处理土壤（即HCM3）的屈服应力（即强度）有所增加。此外，我们发现温度是我们水凝胶凝胶化能力的一个重要因素。在室温下，HCM3表现出较高的团聚体稳定性，与处理后的粗石英砂（HCM1）相比几乎高5.5倍，而在温暖温度下这种差异反应并未持续。一般来说，添加不同数量的高岭石会降低所有处理的饱和水力传导率。最后，明场显微镜成像显示了含有钙-细菌藻酸盐水凝胶的砂粒和粘土颗粒之间的土壤介质基质，该水凝胶改变了不同土壤介质的水力-力学行为。本研究结果可能有助于解决农业中面临气候变化负面影响的与土壤相关的问题。
