RF spectroscopy technique for soil nutrient analysis

The manuscript describes RF Spectroscopy approach to determine the nutrients in the soil. Two different soil nutrients namely urea and potash are considered in this study. In order to obtain the frequency spectra of each of the soil nutrient a cell is designed, which is well shielded from external electromagnetic interferences and has a capability of giving a steady response for a given soil nutrient. The RF responses of each of the nutrients with different concentrations in the range of 10MHz-4.4GHz are obtained using a signal generator and a spectrum analyzer. The results obtained show that at specific frequencies, the RF response of the soil nutrient under study changes in accordance with the changes in the concentration of the soil component and at other frequencies, it shows a flat response. Since the response varies in accordance with the concentration, these results can be used for the prediction of an unknown concentration of a nutrient using a multivariate analysis technique based on the PLSR model, where different concentrations of the nutrients are used as variables.