RT Journal Article SR Electronic A1 Knežo, Dušan T1 Mathematical Model of Harmful Substance Amount in Soil JF Acta Mechanica Slovaca YR 2012 VO 16 IS 1 SP 26 OP 29 DO 10.21496/ams.2012.003 UL https://www.actamechanica.sk/artkey/ams-201201-0003.php AB There are brought into soil various chemical substances as a result of human activity with a positive or negative impact on the soil characteristics. Concentration of the added substances is changing over time and it is important due to many reasons to know the relation between the substance concentration and the time. One of important factors with an impact on the substance concentration in the soil is the natural degradation of materials. That is why there is presented in this paper a mathematical model of substance degradation process during a simple and repeated application of the given substance.