Dielectric Characterization of Sodic Soils in the C-Band: Implications for Moisture Monitoring

Sodic soils, characterized by high sodium accumulation, exhibit poor structure, low permeability, and reduced fertility, impacting agricultural productivity. This study investigates the dielectric properties of sodic soils within the C-band (4–8 GHz) microwave frequency range to assess their correlation with moisture content, electrical conductivity (EC), and bulk density. Soil samples from Buldhana district, India, were analyzed using a vector network analyzer (VNA) and the coaxial probe technique. The results indicate a strong correlation between dielectric constant (ε') and soil moisture (R² = 0.991) and dielectric loss (ε'') with EC (R² = 0.997). Comparative analysis of Dobson, Hallikainen, and Mironov models revealed that Mironov’s model best predicts sodic soil behaviour. The findings demonstrate the potential of microwave remote sensing (MRS) for soil moisture and salinity assessment, aiding precision agriculture and reclamation strategies. Future research should extend to higher frequency bands and machine learning models for enhanced prediction accuracy.