Influence of sunflower fertilization on the dynamics of nutrients in soil and plants in the Western Forest-Step zone

In the geomorphological region of the Pasmove Pobuzhzhia, the impact of different rates and forms of mineral fertilizers was studied to optimize sunflower nutrition with key macronutrients: nitrogen, phosphorus, and potassium.During the flowering stage, the adequate supply of these elements is critically important for the formation of generative organs, successful pollination, and seed filling.Particular attention was paid to examining the dynamics of easily hydrolysable nitrogen, available phosphates, and exchangeable potassium in dark gray podzolized soil under sunflower cultivation.It was proven that the combined application of nitroammophoska and microgranular fertilizers significantly improves the soil's nutrient regime, promoting better uptake of nitrogen, phosphorus, and potassium by plants.The findings revealed that under such treatment, sunflower leaves exhibited the highest recorded content of nitrogen (4,1 %), phosphorus (1,17 %), and potassium (4,44 %).This positively affected the physiological state of the plants and their potential productivity.Control plots without fertilizer application showed the lowest macronutrient uptake, confirming the necessity of mineral fertilization to achieve the target yield.The study underscores the importance of balanced fertilizer application to ensure that, during the flowering phase, sunflower plants have sufficient nutrient resources to realize their full genetic potentialachieving maximum yield and high-quality grain formation.