Сharacteristics of varietal agricultural techniques of forage beet in the conditions of the northern Forest Steppe

Aim. To identify regularities and discrepancies in the yield formation of single- and multi-stem varieties of fodder beet under different systems of mineral nutrition and technological methods of cultivation, to establish their influence on the quality indicators of root crops and to determine the suitability of different forms of roots for mechanized harvesting. Methods. Field, laboratory, agrochemical statistical, measurement and weight analysis. Results. The problematic tasks of fodder beet cultivation in the zone of unstable moisture for the high-quality supply of dairy and meat cattle with juicy fodder in the winter period are considered. On the basis of many years of experimental research, the article reveals the growth processes and features of fodder beet yield formation depending on weather and climate conditions, variety selection of seeds, fertilization systems, and density of planting coenoses and terms of harvesting root crops. Indicators of variation in feed quality, the content of dry matter and nutrients in beetroot roots are given, the homogeneity and deviation of root crops from the axis line, the deepening of roots, and their suitability for mechanized harvesting are also investigated. The following factors had the greatest influence on the formation of fodder beet productivity in 2021–2023: weather conditions (44–58%), fertilization systems (30–36%), varietal characteristics of plants (4–16%). Conclusions. Multi-stem varieties were superior in yield to single-stemmed forms by 5–21% and provided an increase in yield at the level of 3–15 tons. Among multi-stemmed varieties, the Brigadyr variety (Germany) and the Sonet variety (Ukraine) stood out with the highest productivity. Against the background of N45Р45К45 and full mineral nutrition N45Р45К45 + a complex of macro and microelements, these varieties, under a fairly favorable water regime in the pre-autumn and autumn periods in 2021–2022, ensured the maximum yield of root crops, more than 82 t/ha. In the dry year of 2023, the yield of root crops of these varieties decreased by 1.3–1.4 times and amounted to 66.8 and 63.5 t/ha, respectively. In terms of chemical composition, the best quality of root crops was formed by single-rooted varieties, in which the content of dry matter exceeded 11.2%, which is 0.5–1.2% more than in multi-rooted samples, with the exception of the variety of semi-sugar forms Centaur Poly (dry matter content of more than 12.3%). From the point of view of assessing the suitability of root crops for mechanized harvesting based on morphological characteristics (root penetration into the soil, height of attachment of the root to the root crop, etc.), single-root varieties, in particular Rubicon and Aspor, which formed root crops with a deviation from the row axis of no more than 22%, turned out to be the best.