**Changes in** *Pisum sativum* **L. Plants and in Soil as a Result of Application of Selected Foliar Fertilizers and Biostimulators**

**Hanna Sulewska 1 , Alicja Niewiadomska 2 , Karolina Ratajczak 1,\* , Anna Budka 3, Katarzyna Panasiewicz 1 , Agnieszka Faligowska 1, Agnieszka Wolna-Maruwka 2 and Leszek Dryja ´nski 4**



Received: 14 September 2020; Accepted: 8 October 2020; Published: 13 October 2020

**Abstract:** The aim of this study was to assess the e ffect of selected biostimulators and foliar fertilizers on plant development, plant yield, soil fertility and soil biochemical activity (dehydrogenases, phosphatases, catalases) during the cultivation of pea (*Pisum sativum* L.). A field experiment was conducted between 2016 and 2018 at the Gorzy ´n Experimental and Educational Station, Pozna ´n University of Life Sciences in Poland. The following treatments were tested: (1) control; (2) Titanit; (3) Optysil; (4) Metalosate potassium; (5) Rooter; (6) Bolero Mo; (7) Adob Zn IDHA; (8) Adob B and (9) Adob 2.0 Mo. Adob Zn IDHA stimulated yields, especially under average moisture conditions and less so in drought conditions, and the di fferences compared to control amounted 8.36 and 4.3%, respectively. The results showed a close relationship between the e ffects of the biostimulators and foliar fertilizers and weather conditions during the study. It was not possible to determine whether any of the biostimulators or foliar fertilizers had a positive e ffect on pea seed yield in any year. Similarly, it was di fficult to clearly determine the e ffect of the biostimulators and fertilizers on biochemical activity in the soil, although soil enzyme activity was influenced most by application of the Bolero Mo fertilizer. In all study years, biological nitrogen fixation was always greater after the application of a biostimulator/fertilizer treatment.

**Keywords:** maximum photochemical e fficiency of photosystem II; chlorophyll content index; soil enzymatic activity; biological index fertility; nitrogenase activity; microelements fertilization (Ti; Si; B; Mo; Zn)
