The broader impact/commercial potential of this Small Business Innovation Research (SBIR) project stems from the need to substantially improve nitrogen (N) use efficiency in crop production and thereby improve profitability for farmers, while simultaneously reducing the adverse effects of agriculture on the environment. Currently, less than half of the N fertilizer applied to agricultural fields is used by the crops to which it is applied. The remaining N is either leached from the soil or lost to the atmosphere as nitrous oxide - potent greenhouse gas. This inefficient use of N fertilizer by crops is an economic burden for farmers, cause serious water and air quality problems, and contribute about 2.5% of total U.S. greenhouse gas emissions. Furthermore, these N losses represent a tremendous energy inefficiency, because the production of synthetic N fertilizer is the largest energy input in production agriculture. The key to improving N use efficiency in crop production is applying the right amount of N fertilizer in the right place at the right time. The proposed sensor technology would be disruptive to existing agricultural technology and practices, wherein N fertilizer is applied at a uniform rate across agricultural fields, and improve profitability for farmers.This SBIR Phase I project proposes to demonstrate the feasibility of a robust field-mobile soil nitrate (NO3-) sensor utilizing mid-infrared technology to facilitate precision N fertilizer applications. Mid-infrared spectrometers have historically been large, expensive, and fragile laboratory instruments that require substantial sample preparation, thus preventing their use as mobile optical soil NO3- sensors. The scope of the Phase I research will focus on three objectives: 1) The design and development of a robust and low-cost mid-infrared spectrometer that uses a diamond attenuated total internal reflectance (D-ATR) probe to measure NO3- levels; 2) The design, construction, and testing of a chisel shank-tool bar system that houses the spectrometer and D-ATR probe; and 3) the development of control and data processing and analysis software to manage the system. Anticipated technical results of Phase I will provide a prototype that can measure NO3- in the upper 30 cm of soil, not just at the surface, by enabling modulation of the depth of the shank and the probe as the system is pulled through a field, and self-cleaning of the system as soil is continuously moved across the optical surface of the diamond by the forward motion of the tractor.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.
