Internet of Trees (IoTr): A Low-Cost Single Stub Lorentz Resonator For Plant Moisture Sensing

Abstract

The water content of plants plays a significant role in the safety and maintenance of plants' health. Low moisture content in leaves can damage the plants, thus early detection of water content requires very high sensitivity sensors. In this paper, we propose a plant moisture sensor based on Lorentz dispersion to detect plant's moisture level of different concentrations. The high sensitivity of Lorentz sensor comes from its narrowband resonant characteristics manifested by rapid slope change of its phase spectrum, a phenomenon known as anomalous dispersion. This unique signature in its phase spectrum adds a second degree of freedom in sensing and detection, as well as removes ambiguity in the identification of the resonant frequency. We practically measured the moisture content of different samples of leaves and analyzed quick distinctive deviations in the phase and magnitude responses of the sensor based upon the water content in the leaves. The proposed plant moisture sensor is supposed to be integrated with an internet network to inform the farmers and agriculturalists about plants' health. In this way, the concept of Internet of Trees (IoTr) can be employed. Consequently, timely watering of the plants, as well as appropriate usage of water will be guaranteed.