Experimental test results for heavy metal contents in irrigated soils and toxicity class determinations of the test soils are presented. The heavy metal pollutants in southern Russian soils are complexes of chemical, oil-refinery, petrochemical, metal processing, and other installations. A statistically significant direct dependence of the soil Ca content and the Pb-210 concentration in it (correlation coefficient 0.97) is found and indicates that insoluble Pb-210 is incorporated into carbonates. The pollutant soil content was also found to affect directly the morphological features of Hercules tomato plants. The growth dynamics of the plant aerial part showed that the sprout length diminished with increasing soil toxicity in zone 1 sandy loamy southern Russian soil (toxicity class II). © 2020, Springer Science+Business Media, LLC, part of Springer Nature.