The effect of applied fertilization treatments on grain yield and harvest residues of broad bean (Vicia faba ssp. eufaba var. major Harz.)

The experiments were conducted on the demonstration field of the Agricultural Institute of the Republic of Srpska, from 2021 to 2023. The aim of this research was to examine the effect of applied fertilization treatments on the yield of grain and harvesting residues of broad beans under the agro-ecological conditions of the Banja Luka region. Sowing was done manually in the second half of March each year of the study. The experiment was set up in four replications using a randomized block design, with the size of the basic plot being 10 m². For these trials, seed from the broad bean population from the Institute's collection was used, with a sowing rate of 220 kg ha⁻¹. During the study, four fertilization treatments were tested: control (T1), NPK 15:15:15 at a dose of 300 kg ha⁻¹ (T2), biostimulator Slavol S at a dose of 250 ml ha⁻¹ (T3), and NPK 15:15:15 at a dose of 300 kg ha⁻¹ + biostimulator Slavol S at a dose of 250 ml ha⁻¹ (T4). The following parameters were monitored during the study: grain yield per unit area (kg ha⁻¹), harvesting residue yield (kg ha⁻¹), biological yield (kg ha⁻¹), the share of empty dry pods in the harvesting residues (%), the share of dry matter in the plant in the harvesting residues (%), and the harvest index (HI, %). During these experiments, the grain yield of beans ranged from 1,096.7 kg ha⁻¹ in treatment T1 (2021) to 3,240.0 kg ha⁻¹ in treatment T4 (2023). The highest average grain yield during these studies was achieved with treatment T4, amounting to 2,679.9 kg ha⁻¹. The average yield of harvesting residues during the study ranged from 3,049.7 kg ha⁻¹ (T1) to 3,986.8 kg ha⁻¹ (T4). The share of empty dry pods in the total harvesting residue yield varied from 25.5% in treatment T1 (2022) to 36.5% in treatment T4 (2021). On the plots where only the biostimulator (T3) was used, the lowest harvest index was recorded (31.5%), while the highest was achieved with treatment T2 (40.9%).