Effect of Temperature on the Dielectric Constant of Urea-Doped Soil

Abstract

Soils are collected and dried for 12 hours at room temperature using a muffle furnace and ground to form powder. The powder is mixed with polyvinyl alcohol solution and formed into a thin pellet having a diameter of 3cm and a thickness of 1.02 mm using a Hydrostatic Press. Dielectric constants are measured for different temperatures using the LCR meter SM6019. The variation of the dielectric constant with frequency and temperature has been plotted for both the real and imaginary components. Dielectric constant at low frequency is high but decreases with the decrease of frequencies and is almost constant at higher frequencies.  This shows that the dipoles and space charges are no longer able to follow the rapidly alternating electric field, leaving only electronic and ionic polarisation contributions at high frequencies. The result signifies how urea affects the dielectric constant of soil allows for the development of more accurate soil moisture and nutrient sensors.