<p>Salinization poses a serious threat to agricultural soils limiting crop germination, growth, and productivity. Increased soil salinity can cause changes in microbiological soil properties. The effect of chloride salinization on soil enzymatic activity and allelopathic activity of soil fungi was tested in a field experiment over 120&#xa0;days. This study demonstrated that toxigenic fungi might enhance the phytotoxicity of agricultural soils exposed to salinization along with the inhibitory effect of salt on plant growth. The results revealed the long-lasting effect of salt on soil enzymatic activity and communities of soil fungi. The lasting effect of salt on fungal communities led to changes in their structure and allelopathic activity. Due to the salinization of soil, the abundance of soil fungi decreased while the ratio of fungal species with phytotoxic properties increased contributing to the formation of a microbial community dominated by fungi with high allelopathic activity. The coefficients of allelopathic activity increased in soil under salt stress. The study of the allelopathic activity of soil microorganisms is important for the assessment of the ecological state of the agricultural soils, protection of soil cover, increasing soil fertility, and rehabilitation of disturbed lands.</p>