Effect of sideral binary mixtures with sunflower on the quality and fertility of typical chernozems

In the field experiment, the effect of binary sideral mixtures with sunflower on the content of humus, mobile phosphorus and exchangeable potassium in arable and sub-arable horizons of typical heavy loamy chernozem was studied. It is shown that the use of mixed agricultural communities for sideration can be one of the sources of reproduction of potential and effective fertility of chernozems in the Central Сhernozem District. It was found that the influence of the agrocenotic effect in binary mixtures of sunflower with soy, payza, buckwheat of the Krylataya variety and buckwheat of the Demeter variety led to a significant increase in the content of humus, mobile phosphorus and exchangeable potassium in the arable and sub-arable horizons of chernozems under these agricultural communities. It was shown that the effect of the agrocenotic effect on the increase in humus content was equivalent to the introduction of litter manure into the arable horizon of 15.4–25.3 t/ha, in the sub–arable – 13.6–23.0 t/ha. This led to a significant improvement in the quality of the studied soils. An increase in the content of mobile phosphorus under the influence of the mixing factor could be achieved by introducing 88–200 and 88– 138 kg of P₂O₅/ha into the layers of 0–25 and 25–40 cm of soil, respectively. An increase in the content of exchangeable potassium under sideral mixtures in a layer of 0–25 cm of soil by 1.0–2.4 and in a layer of 40–50 cm by 1.7–2.0 mg/100 g of soil would correspond to doses of 300–720 and 510–600 kg K₂O/ha.