Study of Phytotoxicity of Soils of the Astrakhan Region Exposed to Pasture Digression

Pasture digression is one of the main factors of degradation and desertification of territories in the South of Russia. The impact of unsustainable grazing of agricultural animals on plant and soil cover has significant negative consequences, as a result of which the modern vegetation of the semi-desert of the Northern Caspian region has changed greatly over the decades and has taken on unfavorable dynamics. The object of the study was the soils of the Astrakhan region, subject to various stages of pasture digression. Phytoindication was carried out according to the indicators of germination and intensity of initial growth using a traditional test culture (Raphanus sativus L.). As a result of the study, no dependence was established between the indicators of germination and intensity of initial growth of radish on the stages of pasture digression. Soil phytotoxicity depended on soil properties, such as humus content, mobile phosphorus, soil solution reaction, and soil density.