One important soil parameter that is measured in many engineering, geology, soil and environmental science investigations is the soil water content ($\theta$). For example, $\theta$ influences the assessment of soil strength, hydraulic conductivity, groundwater recharge, and soil aeration condition. Measurement of $\theta$ is essential for tracking and managing a number of soil processes. A quick and non-destructive method for determining $\mu$ in soils with drastically different compositions is the gamma ray attenuation (GRA) approach. However, lab physics classes rarely cover GRA. An experiment involving the measurement of $\theta$ using a teaching GRA apparatus is proposed. A Geiger-M\u00fcller detector, a radiation counter, and a radioactive source with a $^{137}$Cs decay were the components of the experimental setup. Four different granulometric compositions of soil samples were examined. The transmitted gamma-ray photon intensity and $\theta$ were found to have strong linear relationships (correlation coefficients ranging from −0.95 to −0.98). There were variations in the soil porosity between the traditional and GRA techniques, ranging from around 7.8% to about 18.2%. Furthermore, a robust linear correlation (correlation coefficients ranging from 0.90 to 0.98) was noted between the GRA and the conventional gravimetric technique for measuring $\theta$. The effectiveness of the teaching GRA apparatus in measuring $\theta$ was confirmed. Additionally, the device enables undergraduate students from a variety of subject areas to be introduced to a few significant facets of the study of contemporary physics.