On-the-go soil nitrogen sensor based on near infrared spectroscopy

Smart agriculture requires a reliable, real-time, and on-site characterization of soil properties. In the characterization of soil, nitrogen is the most important nutrient. Although many techniques have been developed for soil nitrogen estimation over the last few decades, on-site measurement in real-time still poses problems. Spectroscopic techniques are among the ones most utilized for this purpose and near infrared spectroscopy is the most convenient method so far. In this work, a discrete wavelength near infrared spectroscopic device is developed and tested. Calibration is done using partial least squares regression method. The on-field testing versus laboratory testing shows a high value of coefficient of determination.