Biogeochemical characteristics of heavy metals in agroecosystems of Forest-Steppe of Ukraine

Abstract

According to V. Vernadskyi, life on Earth has existed forever. The academician paid considerable attention to the study of soils. The latter are able to accumulate and redistribute chemical elements entering the biosphere between landscape elements. Heavy metals (HM) and other priority toxicants from various sources eventually end up in the upper soil horizons, where their subsequent transformation is determined by soil properties. The residence time of heavy metals in the soil is much longer than in other components of the landscape; they are also slowly removed by leaching, absorption by plants and as a result of exogenous processes. Due to the unique role played by chemical elements in the biosphere, their content in the soil is one of the essential and equal ecological factors that determine the development of living organisms in ecosystems. In connection with the rather intensive development of agriculture in the Forest Steppe, special attention was paid to the distribution of Zn2+ and Cu2+ in the soil cover of this zone. The study of the question of the majority of scientists regarding the arrival of chemical elements in the agro-ecosystems of the soil-climatic zones of Ukraine proved that the largest amount of them comes with mineral fertilizers in the foreststeppe zone. Considering the fact that heavy metals are one of the main sources of environmental pollution, particularly in Ukraine, a comprehensive study of their migration halos in the soil is necessary for the development of effective environmental protection measures. Currently, conducting intensive agriculture using modern agricultural technologies is impossible without the use of fertilizers. Fertilizers are the most effective means of increasing soil fertility, productivity, and improving the quality of crop production. However, a significant drawback of many mineral fertilizers is the presence of toxic heavy metals. Yes, some of these elements in small quantities can have a positive effect on the growth and development of plants. The effect of systematic application of fertilizers on the fertility indicators of typical and gray podzolized chernozem, as well as their effect on the content of mobile compounds of elements in soils, was studied. According to the data, with the systematic introduction of increased doses of fertilizers, elements can accumulate in the soil in significant quantities, which negatively affects the properties and fertility of the soil, the harvest and its quality. Heavy metals are among the main toxicants contaminating grain products. As you know, the rates of dispersion and involvement of chemical elements in the biogenic cycle have increased significantly over the past decades, and their extremely high impact on living organisms gives reason to classify them as particularly dangerous pollutants of the biosphere. This is due to the fact that heavy metals are characterized by high toxicity at low effective concentrations, accumulate in individual links of the trophic chain and create a long-term real danger to the existence of living organisms.