ERI: Crop-FIT: Technology to Support Integrated Wearable Fitness Trackers for Plants

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).

The most promising strategy for producing enough food for humans and livestock in the future is to make farms more efficient, profitable, and sustainable in their use of nonrenewable resources. Studies report that drought stress alone yields up to 21% and 40% of global reductions in wheat and maize productions, respectively. In addition, agriculture accounts for 55 to 60% of methane emissions and 21 to 25% of carbon-di-oxide emissions globally, thus poorly planned and unsustainable agriculture practices contribute substantially to global warming.

Lack of real-time monitoring capabilities of crop health remains one of the central limiting factors for simultaneously mitigating productivity losses and adverse environmental impacts of agriculture practices. There has been a significant thrust in the development of wearable medical devices. However, their applications remain heavily unexplored in plants.

Toward this end, this project will develop new crop-wearable technologies that can monitor the levels of plant hormones (which denote a plant’s first response to its environment), as well as record plant tissue remodeling under environmental stressors (e.g., drought, heat, and salinity stresses). This technology could be a pivotal tool in precision farming enabling real-time tracking of the fitness of plants, with direct benefit to the agricultural society.

The findings from this project will aid in engineering higher-performing, stress-tolerant crop cultivars and setting up on-demand irrigation schedules in the long run, thus preventing the over-application of nonrenewable agrochemicals while simultaneously increasing the production. This project will also train students from minority backgrounds and the producer community on the productivity advantages of sensors-driven precision farming.

This research aims to design, fabricate, and validate integrated, in-situ plant sensors for catalyzing the next generation of crop engineering and precision farming. Real-time monitoring of crop parameters is crucial for implementing immediate interventions to mitigate productivity losses and adverse environmental impacts. Sensors for precision farming applications are limited to indirectly estimating crop needs and health issues from weather conditions, soil properties, or aerial imagery that do not provide chemical profiling in plants, thereby lacking information on the onset and progression of crop health conditions.

Hence, there is a significant gap in knowledge regarding precisely and directly quantifying plant needs and their responses to environmental conditions. This research proposes a holistic solution to this problem by developing an integrated, multiplexed stem sensor for in-situ and quantitative profiling of four key phytohormones/secondary metabolites, which denote a plant’s first response to its environment.

The device is comprised of an array of electrochemical sensors, integral microfluidics, and data processing in an embedded platform for in-situ collection and monitoring of phytohormones in sap. The sensor will be validated with maize grown under abiotic stress conditions to (1) analyze the sensor’s sensitivity, selectivity, robustness, and impact on plant growth, (2) elucidate the dynamic correlations between the phytohormones under environmental stress conditions through multiplexed sensing, and (3) harness these data streams to differentiate the impact of heat/drought/salinity stresses on plants.

The second thrust of this research is to design and simulate a photonic crystal-based fiber-optic bundle for use in real-time root endoscopy and spectroscopy in living plants. This first-of-its-kind fiber bundle will be pivotal in imaging root zone and monitoring root exudate metabolites in real-time. The combined analysis of tissue-specific (shoot versus root) metabolites and deciphering the dynamic tissue remodeling will enhance our fundamental understanding of metabolite gradients across the whole plant, real-time adaptation of roots to stressors (questions that remain unexplored in previous studies) and illuminate a pathway for new crop breeding strategies.

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.