## 3 Results and Discussion
### Pot Experiments
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Object**} & **Intensity of Photosynthesis Net (PN)** & **Transpiration Rate (E)** & **Stomatal** & **Intercellular CO\({}_{2}\)** \\  & **Photosynthesis Net (PN)** & **(E)** & **Conductance (g\({}_{\text{s}}\))** & **Concentration (C\({}_{\text{i}}\))** \\ \cline{2-5}  & **\(\boldsymbol{\mu}\)mol(CO\({}_{2}\))m\({}^{-2}\)s\({}^{-1}\)** & **mmol(H\({}_{2}\)O)m\({}^{-2}\)s\({}^{-1}\)** & **mmol m\({}^{-2}\)s\({}^{-1}\)** & **mmol L\({}^{-1}\)** \\ \hline Control & 14.4 \({}^{\text{a}}\pm 0.1\) & 2.11 \({}^{\text{a}}\pm 0.05\) & 0.07 \({}^{\text{a}}\pm 0.002\) & 45 \({}^{\text{a}}\pm 0.5\) \\ \hline Ff\_1 & 17.5 \({}^{\text{b}}\pm 0.1\) & 2.36 \({}^{\text{a}}\pm 0.02\) & 0.10 \({}^{\text{b}}\pm 0.001\) & 65 \({}^{\text{b}}\pm 0.5\) \\ \hline Ff\_2 & 18.3 \({}^{\text{b}}\pm 0.1\) & 2.51 \({}^{\text{a}}\pm 0.23\) & 0.11b \({}^{\text{c}}\pm 0.002\) & 67 \({}^{\text{b}}\pm 0.5\) \\ \hline Ff\_3 & 19.4 \({}^{\text{c}}\pm 0.1\) & 2.64 \({}^{\text{a}}\pm 0.02\) & 0.13 \({}^{\text{c}}\pm 0.002\) & 81 \({}^{\text{c}}\pm 0.7\) \\ \hline \hline \end{tabular}  
* Means values with the same lower case are not statistically significant according to the T-Tukey test (\(\alpha=0.05\)). Ff\_1, Ff\_2, and Ff\_3—object with foliar fertilizer applied in doses of 1, 2, and 4 kg ha\({}^{-1}\), respectively. Sf\_1, Sf\_2, and Sf\_3—object with soil fertilizer applied in doses of 30, 40, and 60 kg ha\({}^{-1}\), respectively.  
\end{table} 
Table 1: Mean values of gas exchange parameters in maize leaves, depending on the foliar dose (n = 10). Figure 1: The relative content of chlorophyll in the leaves of maize (CCI) fertilized with utilized foliar (**a**) and soil fertilizer (**b**). Ff_1, Ff_2, Ff_3—object with foliar fertilizer applied in doses of 1, 2, and 4 kg ha\({}^{-1}\), respectively; Sf_1, Sf_2 and Sf_3—object with soil fertilizer applied in doses of 30, 40, and 60 kg ha\({}^{-1}\), respectively. Deficiency of plant nutrients, in particular N, P, Mg, and K, not only leads to a reduction in photosynthesis efficiency, but also contributes to a decrease in the level of transpiration, stomata conductivity, content of chlorophyll, and carotenoids. Under the condition of insufficient nitrogen supply of plants, the number of electron acceptors in PSII decreases. As a result of this process, the activity of RuBisCo and phosphoenolpyruvate carboxylase-PEP carboxylase decreases [27; 28; 29]. Phosphorus is the main component of many important molecules involved in plant growth and the control of key enzymatic reactions. Even a slight lack of phosphorus in plants causes an increase in the chlorophyll content, especially in the leaves. Moreover, a greater deficit of this element causes negative changes in the structure of chloroplasts and, in chlorophyll-protein complexes, causes a decrease in PSII activity [30]. In plant physiology research, non-invasive measurement of fluorescence allows the determination not only of photosynthetic activity, but of also plant responses to adverse environmental conditions, such as shading, the presence of contaminants, and deficiencies of macro- and micro-nutrients [31]. Measurement of chlorophyll fluorescence allows an overall assessment of the physiological state of plants, because it is associated with all metabolic and physiological processes occurring in the plant cell; hence any change in the environment causing changes in these processes will affect the process of photosynthesis [32; 33]. The F\({}_{\mathrm{V}}\)/F\({}_{\mathrm{m}}\) ratio is a measure of the light efficiency in primary photosynthesis reactions, and its value is proportional to the quantum efficiency of PSII photochemical reactions [34]. This parameter is considered a reliable measure of the photochemical activity of the photosynthetic apparatus. For leaves under normal conditions in most vascular species, the F\({}_{\mathrm{V}}\)/F\({}_{\mathrm{m}}\) ratio is around 0.832 relative units.