RII Track-4: NSF: Bio-inspired Solutions to Prevent Soil Erosion in Farmland and Scouring in Fluvial Regions

在美国许多地区，土壤侵蚀已经影响了土地的肥力、农业生产力和作物健康，而气候变化预计会使这一问题恶化。传统上，软弱的土壤用水泥或石灰来稳定；然而，这些措施并不环保，可能不适用于所有类型的土壤，例如富含硫酸盐的土壤。因此，利用生物膜对土壤进行生物稳定可以持续地解决这些问题。生物膜是包裹在保护层中的自然存在的微生物群落。经生物膜处理的土壤有望将土壤颗粒结合在一起，增强强度，减少土壤侵蚀和冲刷。在本研究中，用牙生物膜和硫酸盐还原菌（SRB）等生物膜处理有问题的土壤，以提高其强度。这些新型生物膜首次尝试提高土壤特性。生物膜中较高的有机含量将提高土壤肥力和农业生产力，允许土壤中的碳储存，这有助于应对气候变化。牙科生物膜和SRB在其他领域也有很大的潜力，如开发抗旱作物、自愈混凝土、减轻海岸沙丘迁移、增强边坡稳定性、野火后再造林等。这项研究基础设施改善轨道4 EPSCoR研究研究员（RII轨道4）项目将为南达科他州立大学的一名助理教授提供奖学金，并为一名研究生提供培训。这项工作将与亚利桑那州立大学的研究人员合作进行。该项目的目的是调查利用牙生物膜和SRB增强土壤强度的可行性，从而减轻土壤侵蚀和冲刷，提高农业生产力和堤防和桥梁等民用基础设施的复原力。这个项目的灵感来源于观察，牙菌斑或生物膜一旦硬化，就需要专门的工具将它们从牙齿上移除。如果这样的过程可以复制，利用牙齿生物膜将土壤颗粒结合在一起，就会产生更坚固的土壤，可以抵抗侵蚀，可能会减轻桥梁基础附近的冲刷。预计SRB会在施用石灰之前从土壤中去除有效的硫酸盐，这是作物更好生长所需要的。土壤中硫酸盐离子的缺乏将阻止高膨胀矿物钙矾石的形成，从而减轻硫酸盐引起的隆起。计划进行一系列强度试验和体积变化试验以及冻融试验，以研究在土壤中接种这些生物膜的可行性。将进行初步研究，以调查使用牙生物膜和SRB提高土壤肥力和减轻冲刷的情况。这些技术的成功有可能是革命性的，并可能有助于碳封存。该项目将有助于提高我们对不同气候条件下土壤-生物膜相互作用的认识，更好地了解这种生物膜附着和生长所需的生长速度和最佳条件，以及生物稳定土壤的强度和保湿能力的增长速度。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Soil erosion has affected the fertility of the land, agricultural productivity, and crop health in many regions of the USA, and climate change is expected to worsen this issue. Traditionally, weak soils have been stabilized by cement or lime; however, such measures are not environmentally friendly and may not be suitable for all types of soils, such as sulfate-rich soils. Therefore, the biostabilization of soils using biofilms has been proposed to sustainably address these problems. Biofilms are naturally occurring microbial communities enclosed in a protective layer. Biofilm-treated soils are anticipated to bind soil particles together, enhancing strength and reducing soil erosion and scouring. In this study, problematic soils were treated with biofilms like dental biofilm and sulfate-reducing bacteria (SRB) to increase their strength. These novel biofilms represent the first attempts to enhance soil properties. The higher organic content in biofilms will increase soil fertility and agricultural productivity, allowing for carbon storage in soils, which helps address climate change. There is significant potential for dental biofilm and SRB to be beneficial in other disciplines, such as developing drought-resistant crops, self-healing concrete, mitigating coastal dune migration, enhancing slope stability, reforestation after wildfires, and more.This Research Infrastructure Improvement Track-4 EPSCoR Research Fellows (RII Track-4) project will provide a fellowship to an Assistant professor and training for a graduate student at South Dakota State University. This work will be conducted in collaboration with researchers at Arizona State University. The objective of the project is to investigate the feasibility of using dental biofilms and SRB to enhance the strength of soils, thereby mitigating soil erosion and scouring, and improving agricultural productivity and the resilience of civil infrastructure such as embankments and bridges. The inspiration for this project stems from the observation that dental plaque or biofilms, once hardened, require specialized tools to dislodge them from teeth. If such a process can be replicated to bind soil particles together using dental biofilms, it will result in stronger soils that are resistant to erosion, potentially mitigating scouring near bridge foundations. SRB is anticipated to remove available sulfate from the soil before the application of lime, which is needed for better crop growth. The absence of sulfate ions in the soil will prevent the formation of highly expansive mineral ettringite, thereby mitigating sulfate-induced heave. A series of strength-based and volume change tests, along with freeze-thaw tests, have been planned to study the feasibility of inoculating these biofilms in soils. Preliminary studies will be conducted to investigate the increase in soil fertility and the mitigation of scouring using dental biofilms and SRB. The success of these techniques has the potential to be revolutionary and may aid in carbon sequestration. The project will contribute to enhancing our knowledge of soil-biofilm interactions under different climatic conditions by better understanding the rate of growth and optimal conditions required for the attachment and growth of such biofilms, as well as the rate of increase in the strength and moisture retention capacity of bio-stabilized soils.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.