## 4 Conclusions  
The effects of foliar and soil fertilization produced from calcinated bones on the relative chlorophyll content, gas exchange, and fluorescence parameters of maize were described. The conducted research under pot conditions showed that fertilization with utilized foliar and soil fertilizers increased the relative content of chlorophyll in maize leaves and increased the value of gas exchange parameters and chlorophyll fluorescence. The tested fertilizers improved the physiological parameters of the plants, indicating their fertilizing efficiency. The efficacy of the tested fertilizers should be verified at the field scale. Conceptualization, methodology and writing--Original draft, M.B., N.M.; Formal analysis, J.G. ; D.B.-J. ; Investigation, M.S. ; P.A. ; G.G. All authors have read and agreed to the published version of the manuscript. The research was conducted as part of the project entitled \"Development of innovative fertilizers on the basis of an alternative source of raw material\" No. BIOSTRATEG1/270963/6/NCBR/2015 co-financed \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Object**} & **Maximal Photochemical** & **Maximum Quantum Yield of** & **Performance Index** \\  & **Efficiency of PSII (F\({}_{\text{v}}\)/F\({}_{\text{m}}\))** & **Primary Photochemistry (F\({}_{\text{v}}\)/F\({}_{\text{0}}\))** & **(PI)** \\ \hline Control & 0.753 \({}^{\text{a}}\)\(\pm\) 0.001 & 3.06 \({}^{\text{a}}\)\(\pm\) 0.1 & 2.72 \({}^{\text{a}}\)\(\pm\) 0.1 \\ \hline Sf\_1 & 0.787 \({}^{\text{b}}\)\(\pm\) 0.002 & 3.56 \({}^{\text{b}}\)\(\pm\) 0.3 & 3.39 \({}^{\text{a}}\)\(\pm\) 0.1 \\ \hline Sf\_2 & 0.771 \({}^{\text{ab}}\)\(\pm\) 0.004 & 3.41 \({}^{\text{b}}\)\(\pm\) 0.1 & 3.14 \({}^{\text{b}}\)\(\pm\) 0.2 \\ \hline Sf\_3 & 0.762 \({}^{\text{ab}}\)\(\pm\) 0.001 & 3.19 \({}^{\text{a}}\)\(\pm\) 0.1 & 2.99 \({}^{\text{b}}\)\(\pm\) 0.1 \\ \hline \hline \end{tabular}  
* Means values with the same lower case are not statistically significant according to the T-Tukey test (\(\alpha\) = 0.05). F\_1, F\_2, and F\_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 4: Average values of chlorophyll fluorescence parameters in maize leaves depending on the dose of soil fertilization (n = 10). \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Object**} & **Maximal Photochemical** & **Maximum Quantum Yield of** & **Performance Index** \\  & **Efficiency of PSII (F\({}_{\text{v}}\)/F\({}_{\text{m}}\))** & **Primary Photochemistry (F\({}_{\text{v}}\)/F\({}_{\text{0}}\))** & **(PI)** \\ \hline Control & 0.753 \({}^{\text{a}}\)\(\pm\) 0.001 & 3.06 \({}^{\text{a}}\)\(\pm\) 0.1 & 2.72 \({}^{\text{a}}\)\(\pm\) 0.1 \\ \hline F\_1 & 0.769 \({}^{\text{a}}\)\(\pm\) 0.001 & 3.44 \({}^{\text{b}}\)\(\pm\) 0.1 & 2.84 \({}^{\text{a}}\)\(\pm\) 0.1 \\ \hline F\_2 & 0.777 \({}^{\text{a}}\)\(\pm\) 0.001 & 3.59 \({}^{\text{b}}\)\(\pm\) 0.1 & 3.15 \({}^{\text{b}}\)\(\pm\) 0.2 \\ \hline F\_3 & 0.798 \({}^{\text{a}}\)\(\pm\) 0.002 & 3.72 \({}^{\text{b}}\)\(\pm\) 0.1 & 3.33 \({}^{\text{b}}\)\(\pm\) 0.1 \\ \hline \hline \end{tabular}  
* Means values with the same lower case are not statistically significant according to the T-Tukey test (\(\alpha\) = 0.05). F\_1, F\_2, and F\_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 3: Average values of chlorophyll fluorescence parameters in maize leaves depending on the dose of foliar fertilization (n = 10). by public funds, at the disposal of the National Center for Research and Development under the \"NATURAL ENVIRONMENT, AGRICULTURE AND FORESTRY\" Program--BIOSTRATEG.