Ways of optimization of lead-polluted black earth soils in the soil-plant system

Abstract

the most urgent problems of today. Ensuring the environmental safety of food raw materials and food products is one of the main tasks that determine the health of the human population and the preservation of its gene pool.

Analysis of recent research and publications. Toxic effects of Pb on human bodies have been confirmed by numerous clinical studies that have shown the negative effects of heavy metals on the nervous, cardiovascular, immune systems and oncology. The works is devoted to the development of detoxification techniques, in which scientists proposed to reduce the content of heavy metals in chernozems by detoxifying soils by growing battery plants on them, which will «extract» heavy metals from soils disinfecting them. The disadvantage of the proposed technologies is the economic costs borne by farmers, producers and consumers. Farmers will suffer financial losses due to idle sown areas and the cost of seed. Producers will be forced to raise prices for the final food product as a result of reduced consumer purchasing power.

Formulation of the purpose of the article. The aim of the article is to determine ways to optimize lead-contaminated chernozem soils in the system «soil – plant» (on the example of chernozem soils within the test sites on the territory of the collection nursery «Agrotek» in Kyiv region).

Presentation of the main research material. The article presents the results of a study of ways to optimize lead-contaminated chernozem soils in the system «soil – plant». The objects of the study were soybean and chickpea varieties of different vegetation varieties, namely: ultra-early varieties, maturation period 95… 105 days. Мedium, maturation period 100…115 days. Мedium-ripe varieties maturation period115…125 days. Early ripening varieties of chickpeas growing period 95…115 days, and medium-ripe sotu chickpeas, growing period 115…125 days. Experimental studies were conducted during 2019 – 2021 within the test sites on the territory of the collection nursery «Agrotek» in Kyiv region. The method of ion exchange and liquid chromatography on the liquid chromatograph Shimadzu LC-20 (Japan). Studied the variability of nutrients (protein, fat, carbohydrates) in soybeans and chickpeas of different vegetation varieties. With the help of the MATLAB program, mathematical optimization was carried out and the five-year dynamics of protein, fat, and carbohydrate content in legumes grown on chernozem soils of the «Agrotek» collection nursery in the Kyiv region was determined. By the method of inversion-voltammetry with the help of voltammetric analyzer «ABA-3» (Russia) which is equipped with an indicator electrode for the determination of lead, the concentration of Pb in chernozems and soybeans and chickpeas with different protein content was studied. Concentrations of Pb in soybean and chickpea grains depending on the chemical composition of soils for cultivation were grown and studied at the test sites of the «Agrotek» collection nursery.

Conclusions. As a result of experimental studies, it was found that the contamination of chernozem soils Pb and subsequent processes of its translocation in the system «soil – plant» have negative consequences and are manifested in the accumulation of toxicants in plants. It is significant that the largest metal-accumulating properties have cultivated early-ripening legumes, and the smallest – medium-ripe. It was determined that the indicators of Pb concentration in the storage organs of legume assimilants are influenced to a greater extent by the protein content in them than by mobile forms of Pb, which come due to translocation from soils contaminated with Pb. It is established that with the increase of protein in the organs of plant assimilators, the indicators of accumulation of toxic concentrations of Pb increase. Given that the genetic characteristics of chernozems allow us to consider them the most environmentally friendly soils in terms of anthropogenesis, however, they deposit contaminants and, accordingly, require optimization and development of detoxification methods. It has been experimentally established that when growing legumes of different vegetation varieties on chernozems contaminated with Pb, the intensity of their detoxification to obtain environmentally friendly plant products can be distributed as follows: N₁₈₀P₁₈₀K₁₈₀ + Pb + lime + manure > N₃₆₀P₃₆₀K₃₆₀+ Pb > N₁₈₀P₁₈₀K₁₈₀ + Pb + lime > N₁₈₀P₁₈₀K₁₈₀ + Pb + manure. The obtained laws provide an opportunity to develop recommendations and propose ways to detoxify contaminated Pb soils. Which will provide an opportunity to significantly reduce budget expenditures, which is socially necessary and cost-effective.