Estimating the Soil Water Content Using Electrical Conductivity, Oven Method and Speedy Moisture Tester

Abstract

Soil samples were taken in order to investigate the spatial soil water content changes at 40 points in a field of 675 m² located on the old Istanbul-Izmit road in Kocaeli-Turkey. The water content values of soil samples collected were obtained using oven and Speedy Moisture Tester (SMT) in the laboratory to correlate with measured electrical conductivity of soil by electrical resistivity method with a 2-electrode system. The results showed a reasonably good correlation between electrical conductivity and water content. The determination coefficient between the water content and the electrical conductivity found by the oven method (R² ≈ 0.8) was higher than that of the SMT (R² ≈ 0.6). The correlation between the water content values of oven and SMT is quite affordable with the determination coefficient (R² ≈ 0.7). Considering the results obtained from Oven and SMT method, it can be concluded that the resistivity method is also successful in measuring soil water content. It is foreseen that resistivity method can be preferred both because it is easy to use, and large areas are faster and economical in measuring soil water content.