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

土壤侵蚀已经影响了美国许多地区的土地肥力、农业生产力和作物健康，而气候变化预计将使这一问题恶化。传统上，软弱的土壤是用水泥或石灰加固的；然而，这种措施并不环保，而且可能不适用于所有类型的土壤，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是为了可持续地解决这些问题。生物膜是包裹在保护层中的自然微生物群落。经过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。在这项研究中，用牙科生物膜和硫酸盐还原细菌(SRB)等生物膜处理有问题的土壤，以增加其强度。这些新型生物膜是提高土壤性质的第一次尝试。生物膜中较高的有机含量将提高土壤肥力和农业生产率，允许土壤中储存碳，这有助于应对气候变化。牙科生物膜和SRB有很大的潜力在其他学科中受益，如开发抗旱作物、自我修复混凝土、减缓沿海沙丘迁移、增强斜坡稳定性、野火后重新造林等。这个研究基础设施改善Track-4 EPSCoR研究人员(RII Track-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。该项目的目的是研究使用牙科生物膜和SRB来增强土壤强度的可行性，从而减轻土壤侵蚀和冲刷，并提高农业生产力和路堤和桥梁等民用基础设施的弹性。这个项目的灵感来自于这样一个观察：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走。如果可以复制这样的过程，使用牙科生物膜将土壤颗粒结合在一起，它将产生更坚固的土壤，抵抗侵蚀，潜在地减轻桥梁基础附近的冲刷。SRB预计会在施用石灰之前从土壤中去除有效硫酸盐，石灰是作物更好生长所必需的。土壤中没有硫酸盐离子，将防止形成高膨胀矿物钙矾石，从而减轻硫酸盐引起的隆起。已经计划进行一系列基于强度和体积变化的测试，以及冻融测试，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，以调查使用牙科生物膜和SRB提高土壤肥力和减轻冲刷的情况。这些技术的成功具有革命性的潜力，并可能有助于碳封存。该项目将有助于通过更好地了解生物膜附着和生长所需的生长速度和最佳条件，以及生物稳定土的强度和保湿能力的增长速度，来增强我们对不同气候条件下土壤-生物膜相互作用的了解。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.