Newly calibrated analytical models for soil moisture content and pH value by low-cost YL-69 hygrometer sensor

• Main Authors: Tan, Weng Yeow, Then, Yi Lung, Lew, Yao Long, Tay, Fei Siang
• Format: Article
• Language: English
• Published: Elsevier 2019
• Subjects: S Agriculture (General); TK Electrical engineering. Electronics Nuclear engineering
• Online Access: http://ir.unimas.my/id/eprint/39425/1/Newly%20Calibrated%20Analytical%20Models%20for%20Soil.pdf; http://ir.unimas.my/id/eprint/39425/; https://doi.org/10.1016/j.measurement.2018.10.071

Soil moisture content and soil pH values, especially in the surface layers of the soil play a significant role in agriculture production in hydrological processes, meteorology observation and horticulture study. This paper proposes an analytical model of estimating the moisture content, acidity and alkalinity in soil through measurement of soil resistivity by an on-site, real-time method. In this study, a low-cost soil resistivity sensor YL-69 was used to characterize the dynamics of soil moisture content and its pH value. Laboratory calibrated regression models were developed for three types of soils, i.e., clay, thionic, and fine sandy loamy to evaluate the effect of soil temperature and the depths of sensor on the apparent soil moisture content and pH value with a single resistive sensor. The prediction models were found to be accurate with the accuracy of 98%. The findings obtained from this study could provide inexpensive and accurate simultaneous soil moisture content and pH value measurement.