Dynamics of weediness of field crops depending on soil cultivation and fertilizer systems in the Northern Steppe

Goal. To study the influence of different systems of basic tillage and fertilization on the dynamics of weediness of field crops in the Northern Steppe of Ukraine to identify the most effective agricultural measures to limit the development of weeds and ensure a sustainable harvest. Methods. Field experiments were carried out in 2022–2024 based on the experimental field of the Institute of Grain Crops of NAAS in a stationary field experiment in a 5-field crop rotation. The effectiveness of moldboard, soil-protective non-moldboard (mulching), and shallow moldboard tillage systems was studied. Field method — to conduct a field stationary experiment; laboratory — to determine the types of weeds; measuring and weighing — to determine the number and weight of weeds in the air-dry state, as well as the crop yield of crop rotation; mathematical and statistical — to analyze the data obtained. Results. The maximum yield indicators were obtained under the moldboard tillage in combination with N45P45K45 fertilization. In particular, the yield of peas (2.44 t/ha) increased by 0.44 t/ha, or 22.0%, winter wheat (5.79 t/ha) — by 1.07 t/ha, or 27.0%, corn (5.56 t/ha) — by 1.06 t/ha, or 30.2%, sunflower — by 0.78 t/ha, or 43.3%, compared with shallow non-moldboard tillage without fertilizers. Conclusions. Under the moldboard tillage, weediness was the lowest in sunflower, corn, winter wheat, and spring barley crops, especially before the ripening phase and the start of harvesting. At the same time, the use of non-moldboard tillage, in particular shallow disc cultivation, contributed to a significant increase in the number of weeds, which was a consequence of the preservation of their seeds in the upper active layer of the soil and less developed plant habituses. Application of mineral fertilizer in a dose of N45P45K45 for all cultivation systems at the end of vegetation reduced the level of weediness, which confirmed the synergistic effect of the combination of fertilization and moldboard tillage.