SitS NSF-UKRI: Wireless In-Situ Soil Sensing Network for Future Sustainable Agriculture

This research proposes a paradigm shift in low-cost, long-life, wireless in-situ sensing networks for the study of soil health and future sustainable agriculture. The sensing network will be enabled through wireless powering by autonomous ground and aerial vehicles. This approach will result in much lower cost underground sensors with no need for battery replacement, thus enabling data collection on far higher spatial and temporal densities than is now possible. The novel sensing network will be demonstrated in a study on the effect of irrigation with alternative water sources. With the world's population expected to surpass 9 billion by 2050, increasing food production threatens soil security, presenting one of the grand challenges of the 21st century. Sustaining high levels of food production depends on irrigated agriculture, which consumes over 70% of freshwater reserves in many regions of the world. Due to the diminishing freshwater sources, alternative water sources, for example reclaimed water, surface water, and coastal water, have been considered and used for agriculture. However, alternative water sources contain contaminants of emerging concern and/or excess nutrients and salt contents. Their impact on soil health and related contaminant effects on the soil ecosystem and productivity remain largely unknown. Therefore, there is an urgent need to develop soil sensing technologies that can effectively indicate the health condition of soils being irrigated using different alternative water resources. The prototype system developed in this project will be demonstrated in such a study, investigating effect of irrigation with alternative water sources. The research results will not only be critical for developing better soil maintenance, protection, and management practice, but also for enabling a wide range of research on soil health and associated links to sustainable agriculture.

The research team plans to achieve the proposed objectives through the following tasks. (1) Develop low-power, low-cost, underground, in-situ soil sensor modules and achieve a reduction in power and cost by one to two orders of magnitude compared to commercial products. Low-power electronics in both discrete and ASIC forms will be designed and fitted to existing sensor probe technology. (2) Develop wireless power transfer and data telemetry systems that can wirelessly transfer power from a source above the ground to an underground sensor module, charging a rechargeable battery or enabling a battery-less underground sensing operation. This approach can greatly simplify the system installation and maintenance. (3) Demonstrate the proposed system operation from a controlled laboratory environment and open field testing. Sensor modules calibration and stability will be investigated to ensure long-term reliable operation. (4) Deploy the wireless sensor technology to investigate irrigation effect on soil health by using alternative water sources. Soil moisture, temperature, and salinity will be measured in-situ and collected wirelessly. Soil pH, ammonia, organic carbon and nitrogen will be measured from collected soil samples. These parameters can indicate soil intrinsic conditions due to different irrigation practices. The research will carry an important impact of soil health to address global food security and sustainable agriculture.

The proposed sensing network and study could enable far more efficient use of fresh water resources in irrigated agriculture. Furthermore, the proposed sensing paradigm could be applied to a wide range of soil health studies with direct societal impact by helping improve soil conditions and agricultural productivity. The project brings together several different disciplines to solve an important problem and will, therefore, train a multidisciplinary cohort of graduate and undergraduate students in a convergent manner. Students will interact with faculty in microbiology, soil science, electrical engineering, and mechanical engineering. Undergraduate students will be incorporated into the project through integration with an entrepreneurially focused senior design program. Middle and high school students will be engaged through participation in science competitions. The team will engage stakeholders early on in the research to ensure that research efforts are grounded in the real practical needs of end users. Research results will be shared with stakeholders through educational programs organized through Utah State University Extension. Finally, research results will be shared at a national meeting of Extension professionals and through the development of online resources.