*3.2. Biological Nitrogen Fixation*

Field analyses of BNF showed that the fertilizer and biostimulant applications significantly enhanced nitrogenase activity during pea cultivation (Table 14). In all the treatments, nitrogenase exhibited higher activity than in the control. During the study period, greatest BNF activity was recorded in 2017, while the greatest nitrogenase activity was noted after the application of Tytanit, when the activity of the enzyme was five times higher than in 2016 and 2018, and six times higher in 2017 than in the control plot. Apart from the control treatment, the lowest BNF value was noted after the application of Adob 2.0 Mo.

**Table 14.** The influence of biostimulator and fertilizer applications on biological nitrogen fixation (BNF; nMC2H4 plant−<sup>1</sup> <sup>h</sup>−1).


Different letters denote significant differences at level α = 0.05.
