Monitoring of chrome and nickel contents in agroecosystems of Central Chernozem region of Russia

The research was carried out within the framework of the state agroecological monitoring program. The goal was to conduct an environmental assessment of chromium and nickel content in agroecosystems of the southwestern part of the Central Chernozem region using the example of the Belgorod region. All analytical studies were carried out in an accredited testing laboratory using generally accepted methods. During the research, it was found that the average gross content of chromium and nickel in the arable layer in leached chernozems is 19.8 and 24.5, in typical chernozems – 20.0 and 24.9, in ordinary chernozems – 20.9 and 26.6 mg/kg, respectively. The average content of mobile forms of chromium in the studied soils was in the range of 0.13–0.14, nickel – 0.37–0.41 mg/kg. Exceeding the levels of the approximately permissible amount of nickel and the maximum permissible concentration of mobile forms of these heavy metals in soils was not detected. In the agroecosystems of the Belgorod region, chromium and nickel are mainly supplied with organic fertilizers, but this does not pose a risk for soil contamination and crop production. The highest average chromium content (0.45 mg/kg) was observed in sunflower seeds, and the lowest (0.22 mg/kg) in corn grain. Soybean grain is characterized by an abnormally high nickel content (4.81 mg/kg), and the lowest concentration (0.63 mg/kg) is observed in corn grain.