Mazur S. Agroecological assessment of the influence of soil herbicides on sunflower biocenose

The thesis is devoted to the study of the influence of soil herbicides on the biocenosis for the cultivation of sunflower. Under the conditions of the Forest-Steppe of Ukraine in the sowing of sunflower, the use of Hezagard provided effective weed control (total biological efficiency – 90.97%, against dicot weeds – 95.6%). The introduction of herbicides violated the structure of soil microbiocenosis, reduced the total number of microorganisms and activated the activity of mineralization processes 1.3 times and the destruction of soil organic matter 1.2 times. The total microbial productivity decreased by 5.2% compared to control and by 11.4% compared to the soil of the natural ecosystem due to the use of Hezagard. At the same time, there was a decrease in soil biological activity in terms of CO2 emissions by 11.6% against control. The negative impact of herbicides on the development and abundance of Lumbricus terrestris individuals in the soil has been established. Inhibition of acetylcholinesterase and activation of the synthesis of glutathione-S-transferase in the earthworm tissues during the first day of contact with Harness and only on the 7th day according to Hezagard was observed. The use of Hezagard provided the sunflower seed yield of 2.64 t/ha, which was dominated by control by 23.9%, and was economically effective (profitability level was 92.1%).