EAGER SitS: Autonomous Soil Nutrient Sensing System

人口增长、激进的耕作方式和气候变化给粮食生产系统的可持续增长带来了巨大压力。过度施肥产生的农业径流和大型养殖场的废物流入自然水源可能导致藻类爆发，减少水中的溶解氧，导致生态系统紊乱和鱼类数量下降。精准农业有数据支持的决策，如细粒度的时空土壤特性（湿度、温度、pH值、营养物质、有机质等），通过增加作物生长和减少污染地表水和地下水的农业径流以及其他负面环境影响，有可能提高农业实践的效率。目前的土壤性质测量方法严重依赖于采集样本进行实验室测试，这在大面积实施时既昂贵又耗时。该项目将研究一种低成本的自主土壤养分传感系统，通过集成微机电系统传感器、探地雷达以及自主无人机无线传感器网络来支持精准农业。该项目包括开发一种无源、低成本、普及、免维护的传感器，该传感器可以无线询问，并提供土壤含水量、温度、pH值和养分浓度的测量。该项目重点检测和评价土壤中硝酸盐和重金属离子浓度，这是农业径流和环境污染物的指标。为此，由表面声波延迟线和连接到反射器的导电聚合物阻抗传感器组成的表面声波传感器将被视为主要的传感模块。传感器可以放置在土壤中进行原位测量。本课题的具体研究目标是：1)确定用于硝酸盐和重金属离子检测的特定聚合物；2)设计、制造和验证表面声波传感器；3)设计和选择合适的天线和探地雷达用于无源传感器的无线测量；4)集成数据分析和通信系统。项目团队在生物化学、雷达和天线设计、微机电传感器、通信网络以及电气、计算机、机械工程和生命科学领域具有共同的研究专长。该项目的成功可以显著改进自主设备，采用新颖的天线、通信系统和营养传感器设计，以合理的成本测量土壤中的信号，并可扩展到更大规模的部署。由此产生的来自多个领域的知识和专业知识的整合，以及新方法和数据的产生，将为从整体设计的角度解决可持续农业中紧迫的社会挑战提供手段。该项目有可能为几个学术和专业学科开辟重要的新方向，这些学科旨在提高社区的复原力，培养一批来自多个学科的本科生和研究生，从事科学研究，为利益相关者创造可用的科学工具，以实现可持续的未来。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。

Population growth, aggressive farming practices, and climate change have put significant stress on the food production system for sustainable growth. Agricultural runoff from over-fertilization and waste from large farms into natural water sources can cause algae outbreaks, reduce the dissolved oxygen in water, resulting in ecosystem disturbance and decline in fish populations. Precision agriculture with data-backed decision-making such as fine-grained spatiotemporal soil properties (moisture, temperature, pH, nutrients, organic matter, etc.) has potential to improve the efficiency of the farming practices by increasing crop growth and reducing agricultural runoff that contaminates surface and groundwater along with other negative environmental impacts. Current practice of soil property measurement relies heavily on taking samples for laboratory testing, which is costly and time consuming for implementation over large areas. This project will investigate a low-cost autonomous soil nutrient sensing system to support precision agriculture by integrating microelectromechanical system sensors, ground penetrating radar, as well as autonomous unmanned aerial vehicle-enabled wireless sensor network.The project includes the development of a passive, low cost, pervasive, maintenance-free sensor that can be interrogated wirelessly and provide measurement of soil water content, temperature, pH, and nutrient concentration. The project focuses on detecting and evaluating nitrate and heavy metal ions concentration in the soil, which are indicators of agricultural runoffs and environmental contaminants. For this purpose, surface acoustic wave sensors that consist of surface acoustic wave delay lines and conductive polymer-based impedance sensors connected to a reflector will be considered as the main sensing modules. The sensors can be placed in the soil for in-situ measurement. The specific research objectives of this project are to: 1) identify specific polymers for nitrate and heavy metal ion detection, 2) design, fabricate and validate the surface acoustic wave sensors, 3) design and select proper antenna and ground penetrating radar for wireless measurement of the passive sensors, and 4) integrate the data analysis and communication system. The project team has a collective research expertise in biochemistry, radar and antenna design, microelectromechanical sensors, and communication networks in the field of electrical, computer, and mechanical engineering as well as life sciences. The success of this project can lead to significant improvement in the autonomous devices with novel antenna, communication system and nutrient sensor designs to measure signals in the soil at a reasonable cost and are scalable for deployment on a larger scale. The resulting integration of knowledge and expertise from multiple domains, and the generation of new methodologies and data, will provide the means to address pressing societal challenges in sustainable agriculture from a holistic design point of view. The project has potential to forge important new directions for several scholarly and professional disciplines that are oriented toward improving community resilience and train a cohort of undergraduate and graduate students from multiple disciplines to engage in scientific research and create usable scientific tools for stakeholders for a sustainable future.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.