In the present study, the effects of two methods for thermal sanitization of soil, by oven and by autoclave, and two non-ionizing
radiation sterilization methods, UVC and microwave on pH, conductivity, dry weight, total number of germs and respiration of
samples from neutral commercial soil were evaluated, using international standard methods. Also, the infrared and UV-VIS
spectroscopy were applied for the determination of chemical properties and structural characterization of humic acid and
hydrophilic indexes at molecular level. The independent variable parameters used in the study were the time and temperature of
sterilizing process and also the radiation dose applied. The results had shown a few variation of pH regardless the method of
sanitization. However, the initial conductivity (EC) of soil (44 μS/cm for control) increases after UVC (54 μS/cm) and oven (68
μS/cm) treatments. Concerning microbial inactivation, the autoclave method is more efficiently because the initial NTG (total
number of bacteria germs) of 96  109 cells/g decreased under the detection limit after this treatment. For autoclaved soil, the
CO2 level remains constant. After application of oven treatment, an intensification of metabolic processes in the sense of
degradation of organic matter occurred besides reducing the number of microorganisms. Also, the result reflected a similar
tendency between the hydrophilic component and humic acid content. Variation of hydrophilic compounds of humic acids
calculated for soil exposed to different techniques suggested that sanitization techniques applied to the commercial soil induced
modification of soil and organic compounds, besides sanitation.