## 3 Results and Discussion
### Methane Yield  
The cumulative production of methane and the concentration of methane in the biogas during the 35 days of the fermentation test are shown in Table 7 and Appendix A. The sample of maize silage (M100) exhibited the highest production of methane throughout the experiment. The measured final methane production was 0.352 \(\pm\) 0.017 Nm\({}^{3}\)/kgys. The results indicate that the increasing weight representation of the Jerusalem enrichoke in the silage samples caused the decreasing production of methane as compared with the production of methane from the maize sample (M100). The production of methane from samples of silage prepared only from the Jerusalem aritchoke (JA100) was 0.274 \(\pm\) 0.013 Nm\({}^{3}\)/kgys. This is by 22.1% less as compared with the sample of maize silage (M100). The sample of M70 + JA30 silage (70% maize silage + 30% Jerusalem aritchoke) exhibited a lower methane production by 18.4% compared with the maize silage; the measured methane production in this sample was 0.287 \(\pm\) 0.014 Nm\({}^{3}\)/kgys. The addition of the Jerusalem aritchoke to the silage samples did not influence the methane concentration in biogas (Table 7, Figure A1b). From day 15 of fermentation, the methane concentration in biogas ranged between 64-65%vol in all tested samples. The results of methane production during the fermentation of maize silage (0.352 \(\pm\) 0.017 Nm\({}^{3}\)/kgys) agree with results published by other authors [10; 56]. The measured methane production from JA (0.274 \(\pm\) 0.013 Nm\({}^{3}\)/kgys) corresponds with the former studies of [PERSON] et al. [32], who measured the production of methane from the ensiled JA to be 0.265 and 0.281 Nm\({}^{3}\)/kgys but claim the methane concentration in biogas ranging from 52-55%vol, which is a lower value than 65%vol reached by us. [PERSON] [57] measured the methane production in the JA silage to be 0.301 Nm\({}^{3}\)/kgys, claiming a methane concentration of 68.4%vol, which are values higher than those recorded by us. [PERSON] et al. [58] inform \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**No.**} & \multirow{2}{*}{**Variant**} & \multicolumn{2}{c}{**Starch**} & \multicolumn{2}{c}{**CP**} & \multicolumn{2}{c}{**ADL**} & \multicolumn{2}{c}{**Lipids**} \\ \cline{3-10}  & & **\%DM \(\pm\) SD** & **HSD** & **\%DM \(\pm\) SD** & **HSD** & **\%DM \(\pm\) SD** & **HSD** & **\%DM \(\pm\) SD** & **HSD** \\ \hline
1 & M100 & 16.14 \(\pm\) 0.00 & A & 9.30 \(\pm\) 0.13 & A & 2.32 \(\pm\) 0.12 & C & 4.36 \(\pm\) 0.09 & A \\
2 & M70 + JA30 & 15.26 \(\pm\) 0.38 & B & 8.33 \(\pm\) 0.14 & B & 3.50 \(\pm\) 0.27 & BC & 3.49 \(\pm\) 0.13 & B \\
3 & M50 + JA50 & 13.54 \(\pm\) 0.06 & C & 8.04 \(\pm\) 0.14 & B & 4.88 \(\pm\) 0.68 & B & 3.41 \(\pm\) 0.20 & B \\
4 & M30 + JA70 & 10.09 \(\pm\) 0.07 & D & 7.33 \(\pm\) 0.05 & C & 7.37 \(\pm\) 1.33 & A & 3.37 \(\pm\) 0.17 & BC \\
5 & JA100 & 9.17 \(\pm\) 0.09 & E & 5.08 \(\pm\) 0.13 & D & 8.08 \(\pm\) 0.31 & A & 2.89 \(\pm\) 0.27 & C \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Contents of starch, CP, ADL and lipids in the prepared model silages. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**No.**} & \multirow{2}{*}{**Variant**} & \multicolumn{2}{c}{**Methene Yield**} & \multicolumn{2}{c}{**Theoretical**} & \multirow{2}{*}{**Methene Content \({}^{*}\)**} \\  & & & **Nm\({}^{3}\)/kgys** & & & **HSD** & **m\({}^{3}\)/kgys** & **\%vol** & **HSD** \\ \hline
1 & M100 & 0.352 \(\pm\) 0.017 & A & 0.427 & 65 \(\pm\) 0.06 & A \\
2 & M70 + JA30 & 0.287 \(\pm\) 0.014 & B & 0.412 & 65 \(\pm\) 0.05 & A \\
3 & M50 + JA50 & 0.302 \(\pm\) 0.015 & B & 0.400 & 65 \(\pm\) 0.06 & A \\
4 & M30 + JA70 & 0.261 \(\pm\) 0.013 & B & 0.374 & 65 \(\pm\) 0.05 & A \\
5 & JA100 & 0.274 \(\pm\) 0.013 & B & 0.346 & 64 \(\pm\) 0.06 & A \\ \hline \hline \end{tabular}  
* M—Maize; JA—Jerusalem aritchoke; \(n=3\); \(\pm\)Standard Deviation (SD); \({}^{*}\) methane content in biogas on day 35 of the experiment.  
\end{table}