Features of Forming Soil Regimes under Sunflower Cultivation with Different Levels of Biologization in Non-irrigated Conditions of the Southern Steppe of Ukraine

Reducing pressure on agrolandscapes while maintaining indicators of economic efficiency is a promising and relevant task for researchers. The article presents the results of a four-year study on the formation of water, nutrient, and microbial regimes in the soil of mid-early ecological group hybrid sunflower crops PR64F66 F1 and Tunca F1 at different levels of biologization of zonal variety cultivation technologies in the conditions of the Southern Steppe of Ukraine: traditional intensive, extensive minimal, organic, and two levels of biologized. The dependence of the reduction in average daily soil moisture consumption on the application of biologization elements was established. The minimum value of the water consumption coefficient over the years of the study was found for organic cultivation technology–407 (PR64F66 F1) and 423 (Tunca F1) m3/ton of dry matter, while the least economical consumption of active moisture for biomass formation was recorded for the extensive cultivation technology variant–523 and 624 m3/ton respectively. Variants with the application of biologization elements in the mineral nutrition system were characterized by significantly higher efficiency and economy of nitrogen consumption from soil reserves. Throughout the vegetation period, under the conditions of intensive sunflower cultivation technology, both the overall population of the plowed soil layer and the number of microflora for individual key groups decreased significantly compared to variants where individual elements of biologization or their complex application (organic cultivation technology) were implemented, by 6.1–40.9%.