Effect of humic preparation and herbicide treatment on chernozem aggregate composition

The influence of the humic preparation and pesticides on dynamics of soil carbohydrates and the soil structure of ordinary chernozem during the cultivation of winter wheat and chickpeas was studied. A positive trend in the growth of the structural coefficient was observed in all variants. This dynamic was confirmed statistically when a humic preparation and pesticides were used together: the difference with the control after treatment was 1.54% (2019). A decrease in the number of water-resistant units from 87.4 to 56.6% was observed on the control during the entire field experiment. There was a statistically significant increase of water-resistant aggregates by 1.9-5.4% when pesticides are applied together with a humic preparation. The growth of the aggregate water resistance criterion (API) from 6.0% to 17.2% was observed in the variant with a humic preparation. The dynamics of soil carbohydrates in all variants in 2017-2018 was insignificantly expressed. The sharp increase in the content of carbohydrates in 2019 is probably associated with a change of culture in the crop rotation link from winter wheat to chickpea. The amount of carbohydrate compounds varies from 1.13 in the control to 1.26% in the variant with the combined use of pesticides and a humic preparation.