Probe-based Semi-permanent Soil Humidity Sensor

The modern agricultural environment has the problems of an aging rural population and a decreasing rural labor population. Recently, smart farms based on information and communication technology have been studied to address environmental issues in agriculture. The smart farm consists of three parts: a data collection unit, a processing unit, and a control unit. Among them, the data collection unit is responsible for collecting necessary information through various sensors in the smart farm. Among the various sensors, the soil humidity sensor is an essential sensor for measuring the moisture in the soil, which is essential for cultivating various crops. However, the soil humidity sensor released as a prototype is vulnerable to corrosion because the probe part of the sensor is in direct contact with the soil. Therefore, the sensor needs to be replaced at regular intervals. To solve this problem, we propose a replaceable probe-type soil humidity sensor that can be maintained inexpensively by replacing only the probe part when corrosion occurs. Experiments are conducted to verify the applicability of the proposed sensor in an actual agricultural environment and its superiority compared to the legacy sensor. Specifically, this study utilizes easily available soil humidity sensor that uses easily available household items such as stainless-steel chopsticks as a probe and verify its applicability through experiments. We propose a method of increasing the usability of the proposed sensor through usability tests in soils of various properties, tests for accurate data measurement even when replacing sensor probes, and tests for minimizing noise in measured values. Finally, we verify that the proposed sensor can be used for a longer time without corrosion through a durability comparison experiment with legacy sensors.