Potentiometric Testing of Soil by Printed Nobel Metal Thick Film Electrode

Abstract

Analysis of precision farming in soil includes monitoring the main nutrient contents such as nitrogen, phosphate, and potassium on agricultural land before farming activities are carried out. The electrochemical soil detectors are extensively used to detect the nutrient of soil due to their low cost, repeatability, multiplexing, and quick response. In this study, AuPt-based thick film electrodes are fabricated for detecting NPK using electrochemical techniques. The electrochemical response is monitored in the soil contains urea, KCl and DAP and it shows good response of DAP. To know the least detection of DAP, concentration varied from 7.5 mM to 500 nM is measured and it is found that the electrode can detect even at 500 nm. The limit of detection is calculated by using the concentration 1 to 10 µM and value shows 291 nM can be detected. The surface morphology of the electrode is captured in scanning electron microscopy before and after voltammeter experiments.