Monitoring of zinc content in agroecosystems the Central Chernozem region of Russia

Studies were carried out in the forest-steppe zone of the Central Chernozem region in the Belgorod and Voronezh regions.  The soil cover was mainly represented by typical and leached chernozems. The purpose of the work was to conduct an agroecological assessment of the zinc content in arable soils, fertilizers and agricultural plants. In the course of studies based on local monitoring data, it was found that the average content of acid-soluble forms of zinc in the arable layer of chernozems is in the range of 36.1-36.5 mg/kg. The results of continuous agroecological monitoring for the eighth and tenth cycles indicate that the weighted average content of mobile forms of zinc in the soils of the Belgorod region is at a consistently low level (0.5 mg/kg), and in the soils of Voronezh it has decreased from 0.45 to 0.30 mg/kg. Accumulation of this element is observed in the soils of roadside ecosystems. An important source of zinc in agroecosystems are organic fertilizers, especially manure runoff and straw-dung composts.  The average zinc content in the hay of perennial legumes ranged from 14.0-17.8, in the main production of leguminous crops - 26.5-43.5, grain crops - 17.6-28.6 mg/kg. In sunflower seeds the content of the element was 41.1, in sugar beet roots – 9.2 mg/kg. In all studied crops, with the exception of sugar beet, the zinc content in the main product was higher than in the by-product. Exceeding the maximum permissible concentrations of zinc in soils and the maximum permissible levels of content in feed products was not recorded.