Iliyana Gerasimova, Ana Katsarova and Zdravka Petkova
Agricultural Academy, ISSAPP “N. Poushkarov”, 1331Sofia, Bulgaria
Gerasimova, I., Katsarova, A. & Petkova, Z. (2024). Export of macroelements with sunflower biomass in dependence of fertilizer types and norms. Bulg. J. Agric. Sci., 30(6), 966–973
The aim of the study was to evaluate the effect of different rates and combinations of nitrogen, phosphorus, potassium, and silicon fertilizers in Alluvial-meadow soil and their impact on the export of basic macronutrients with sunflower biomass in a pot experiment. The test culture was an early to medium-early hybrid Sunflower (Helianthus annuus L.) – Sumiko HTS. The experiment includes 16 variants of fertilization with 3 replications. Data are obtained on the yield of fresh and absolutely dry biomass from the above-ground part and the content of N, P, K, Si, Ca, and Mg in the resulting dry biomass from plants. According to the experimental data obtained, the content and uptake of the examined macroelements with the sunflower biomass are significantly influenced by the imported rates and combinations of fertilizers. The highest is the uptake of nitrogen in the variants with the following norms: N200, N300, and N400. N uptake is the highest also in comparison with all other examined elements. It is established that the changes in the macroelements uptake significantly follow changes in the quantities of the relevant elements in dry biomass in the variants of the experiment. With an increase in fertilization rates, not only the content of N, P, and Si is increased, but also the uptakes with sunflower biomass. This trend with potassium is expressed to a lesser extent.