Dielectric properties of wet and fertilized soils at radio frequencies

Abstract

The dielectric constant ' and dielectric loss " of moist soil and fertilized soil have been measured in the frequency range 10 kHz-2 MHz using a precision LCR meter. The values of ' and " of the wet (Gandhinagar district sandy loam) soil are found to decrease with increase in frequency from 10 kHz to 2 MHz. The value of tan d is found to increase with increase in moisture content in the soil. The peak of tand is found to shift towards lower frequency side as the moisture content in the soil increases. The conductivity spectra of soil show the increase in conductivity * = ' + j" with increase in moisture content in the soil. The value of increases slowly with increase in frequency for wet soil. A dip is observed in the value of " spectra at electrode polarization frequency, which is also observed in complex impedance plane plot of the wet soils. To see the effect of fertilizer on the soil two fertilizers are selected, sulphet of potash (SOP) and zinc chelate. It has been observed that ' and " of the wet fertilized soils decrease with increase in frequency from 10 kHz to 2 MHz. Further, the values of ' and " increase with increase in % concentration of fertilizer in the wet soil. The variation of tan and conductivity with frequency and fertilizer in the soils has also been studied.