Signal Processing in Acoustics for On-Site Measurement of SoilMoisture Content

Precision agriculture is a farming management concept based on observing and responding to intra-fieldvariations. One of the most important soil properties in farming is soil moisture content and it is necessary todevelop new technique for measuring this property in a precision farming system. This study investigates themeasurement of moisture content in soil using an on-site, easy to use and real-time acoustic wave system. Thesystem consists of the propagation of acoustic waves such as sweep frequency sound wave (10-300Hz) andmultiple tone sound wave (120 Hz) through the soil. Some properties of these acoustic waves enable estimationof soil water content such as; peak amplitude (A), total power (TP), total harmonic distortion (THD) and signalto noise ratio (SNR). The results showed that the best model for estimating the soil moisture content was themodel that expressed relationship between A and soil moisture content with R2= 0.999 (using sweep frequency)and relationship between TP and soil moisture content with R2= 0.999 (using multiple tone). It is argued that thechange in the sound characteristics related to the soil moisture content can be used for a continuous monitoring and control of irrigation of crops.

کلیدواژه ها:

Acoustic waves ، Signal Processing ، Soil moisture content ، Sound properties