SBIR Phase I: Low-cost in-planta nitrate sensor

The broader impact/commercial potential of this Small Business Innovation Research (SBIR) project is to develop technology to address a significant pain point for farmers associated with reducing nitrogen fertilizer input costs. The technology is based on in-planta sensor technology that will allow farmers to more carefully and precisely tailor nitrogen applications to each part of each field. By monitoring nitrate accumulation within plants, farmers will receive real time readouts of which fields and which portions of fields are nutrient constrained and could produce more yield following the application of additional nitrogen fertilizer. These readouts also will identify those fields that already have sufficient nitrogen, meaning that further applications would simply reduce farmer profit and environmental sustainability. Widescale adoption and use of these sensors will not only improve farmer profitability, but also improve water quality and ecosystem health via reductions in agricultural losses of reactive nitrogen. This SBIR Phase I project proposes to develop an in-planta sensor for monitoring nitrate concentrations in plants at low cost and in near real time. Existing stalk nitrogen measurement must be conducted in a laboratory setting, requiring farmers to collect samples, mail them to a testing lab, and wait from one to two weeks to receive test results. The cost of the laboratory testing is high enough that only a fraction of farmers conducts nitrogen testing. The in-planta nitrate sensor technology will allow farmers to appropriately sample their fields and provide rapid feedback, allowing farmers (or their crop advisors) to incorporate the data into real-time decisions. This project seeks to develop an in-planta sensor through the fusion of silicon-based microelectromechanical systems (MEMS) technology and novel nanomaterials. The project will overcome major technical challenges through improving materials, fabrications, packaging, and validation, including optimizing MEMS fabrication processes to minimize sensors at low cost, improving packaging robustness for sensors, and validating sensor prototypes in a greenhouse. The in-planta sensor will directly detect stalk nitrate concentrations with minimal invasion, while being robust to interference from other ions present in the plant stem or stalk. 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.