Physicochemical properties of a Haplic Chernozem soil were measured while applying fertigation in a natural grassland during the growing season in a hemiboreal climate with irrigation management based on the decision support system–fertigation simulator (DSS-FS) model. The experimental field was divided into four parcels which were exposed to four different irrigation treatments: fertigation with nutritive solution A [electrical conductivity (EC)=2 mS⋅cm−1, pH=6), fertigation with nutritive solution B (EC=1 mS⋅cm−1, pH=6), irrigation with raw water without any injected fertilizers (EC=0.27 mS⋅cm−1, pH=6.5), and control parcel (no treatment). Rainfall effect on soil desalinization through salt leaching was monitored by comparing the evolution of soil electrical conductivity during and after the growing season. The soil electrical conductivity of the chemigated parcels (parcels A and B) was higher than the control parcels (parcels C and D) at the end of the growing season. This difference decreased significantly, becoming negligible after the winter due to an efficient desalinization effect of rain and snow.