Modified Alex-Behari model for soil moisture as a function of salinity, texture and frequency

Alex and Behari obtained experimental soil moisture data at microwave frequencies and computed emissivity from these. Following this they suggested an empirical model which provides a good agreement up to a soil moisture value of 25%. Taking into consideration the soil texture, the modified Alex-Behari (MAB) model provides agreement with the available data up to 40%. A non-linear relationship between volumetric soil moisture and emissivity is obtained. The dielectric constant shows an increase with volumetric soil moisture. The dielectric properties of the soil are known to depend on soil moisture content along with other factors like salinity, texture and frequency. In the present investigations the experimental dielectric constant of various types of soils was taken in the frequency range (1.4-18.0 GHz) to fit the modified model in the given range of moisture content. The computed data show that the real part of the dielectric constant decreases and imaginary part increases with soil salinity. It is suggested that the proposed model will be of interest to agricultural scientists, and applicable to remote sensing of salt-affected areas.