Effect of Pesticide and Humic Preparation on the Soil Structure during Pea and Chickpea Cultivation

Abstract

The article presents the results of a 3-year experiment to study the soil structure with the combined use of insecticides and a humic preparation. Crops were peas (Pisum sativum) and chickpeas (Cicer arietinum). The experiment was carried out in 2019–2021 at the experimental fields of the Federal Rostov Agrarian Scientific Center, located in the Rostov region in the south of the European part of Russia (47°21′ N, 39°52′ E). Soil was Calcic Chernozem Loamic. The studies were carried out both without fertilization and with the use of mineral fertilizers (N40P40K40). Sowings of leguminous crops were treated with a mixture of insecticides and a humic preparation in the phase of bean formation. The humic preparation BIO-Don10 was obtained according to the authors’ technology by alkaline extraction from vermicompost—a product of manure processing by compost worms of the Eisenia foetida species. The preparation contains salts of humic acids and fulvic acids in the amount of 1.9 g/L; the concentration in the mixture with the insecticide was 0.002%. An increase in the structure and water resistance coefficients was observed. A decrease in the block fraction and an increase in the total number of agronomically valuable aggregates were substantiated. It was found that in the cultivation of legumes, the application of mineral fertilizers had a negative effect on the structure of the soil, while, when using pesticides, the structure was preserved better by the end of the growing season. The revealed patterns can be associated with the activity of microorganisms participating in the hydrolysis of organic compounds that stabilize soil aggregates.

The Role of Organic and Mineral Fertilization in Maintaining Fertility and Productivity of Cryolithozone Soils

“…Being not fertilized and agriculturally used for a long period of time, Eutric Albic Retisols, the organic matter of which is highly mobile, normally develop undesirable humus features accompanied with a decrease in the C HAs /C FAs ratio mainly due to an increase in FAs (including aggressive fractions) and to a lesser degree due to a decrease in HAs. The most serious changes in the humic composition were recorded during long-term cultivation of row crops [46][47][48][49].…”