干旱区生态环境知识资源中心

The Astrakhan region at the Caspian lowland, characterized by semi-arid climate, is one of the most important regions in the agricultural sector of Russia. However, due to contamination of soils with heavy metals, there is not only a decrease in productivity, but also an increased threat from toxic products. The present study was conducted to analyze the content of heavy metals and their accumulation in irrigated light-brown soils of the arid zones of Russia and the content of heavy metals accumulated in the biomass (stems and leaves) of medicinal and forage plants cultivated in these conditions. The safety or toxicity of these plants was assessed by comparison to the antipollution standards. Results showed the distribution and content of heavy metals in soil horizons: zinc, manganese, nickel and chrome accumulated in the upper layers of soil, strontium in carbonate-illuvial horizons, while lead was uniformly distributed over the soil profile. The role of irrigation in decreasing active forms of certain heavy metals was also noticed. In the study, the selective capability of various plants to accumulate heavy metals was also illustrated.