## 3 Results
### Meadow Yield  
Table 3 summarizes the meadow sward dry matter values obtained in the individual cuts and the annual total. Regardless of the cut and the area (with high/low groundwater levels), it can be observed that the application of the silicon antitranspirant contributed to a reduction in yield of aboveground biomass. Looking at individual cuts, the biggest reduction occurred in the third cut of 2022. This amounted to \(-42\%\) in the site with high groundwater levels and \(-25\%\) in the site with low groundwater levels. The smallest negative impact of the antitranspirant was observed in 2022 during the second cut. The yield reduction was \(7\%\) and \(4\%\) for LWL and HWL, respectively. Analyzing the yields obtained from the whole year, it can be observed that silicon had a stronger negative effect on yield in the area with a higher groundwater level--it caused a reduction of yield biomass by 17-18%, depending on the year. In the case of lower groundwater levels, the yield reduction was smaller, and reached \(14\%\) in 2021 and \(11\%\) in 2022. The two-year results clearly suggest that applying the silicon antitranspirant negatively affected yield by reducing the dry matter of the aboveground biomass. Concerning the impact of the groundwater level, it can be observed that a higher water level positively affected the biomass yield. In 2021, the yield from the HWL plot equaled 12,693.04 kg\(\cdot\)ha\({}^{-1}\) and was \(5.4\%\) higher than that from LWL plot (12,047.61 kg\(\cdot\)ha\({}^{-1}\)). The \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & & \multicolumn{4}{c}{**Growing Season**} & \multicolumn{4}{c}{**Annual**} \\  & & \multicolumn{4}{c}{**(gCO\({}_{2}\)-C\(\cdot\)m\({}^{-2}\).Growing Season\({}^{-1}\))**} & \multicolumn{4}{c}{**(gCO\({}_{2}\)-C\(\cdot\)m\({}^{-2}\).Year\({}^{-1}\))**} \\ \hline
**Year** & **Plot** & **HWL** & **HWL\_Si** & **LWL** & **LWL\_Si** & **HWL** & **HWL\_Si** & **LWL** & **LWL\_Si** \\ \hline \multirow{3}{*}{2021} & Reco & 2310.57 & 2327.85 & 2175.86 & 2225.61 & 2445.37 & 2446.85 & 2291.03 & 2353.52 \\  & GPP & \(-1950.27\) & \(-2245.61\) & \(-1944.28\) & \(-1743.83\) & \(-2131.12\) & \(-2397.30\) & \(-2106.13\) & \(-1912.36\) \\  & NEE & 360.31 & 82.24 & 231.58 & 481.77 & 314.25 & 49.55 & 184.89 & 441.17 \\ \hline \multirow{3}{*}{2022} & Reco & 2092.23 & 1996.66 & 1723.40 & 1810.22 & 2234.95 & 2129.56 & 1847.76 & 1924.61 \\  & GPP & \(-2321.79\) & \(-2508.84\) & \(-1829.08\) & \(-1976.68\) & \(-2389.14\) & \(-2565.75\) & \(-1888.21\) & \(-2043.31\) \\ \cline{1-1}  & NEE & \(-229.55\) & \(-512.18\) & \(-105.69\) & \(-166.46\) & \(-154.19\) & \(-436.19\) & \(-40.45\) & \(-118.70\) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Annual and growing season cumulative Reco, GPP, and NEE fluxes for individual plots for 2021–2022. \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{4}{c}{**2021**} \\  & **1 st Cut** & **2 nd Cut** & **3 rd Cut** & **Year** \\ \hline HWL & 4365.39 & 4621.57 & 3706.08 & 12,693.04 \\ HWL\_Si & 3489.42 (\(-20.1\%\)) & 3999.88 (\(-13.5\%\)) & 2939.83 (\(-20.7\%\)) & 10,429.13 (\(-17.8\%\)) \\ LWL & 4587.14 & 3993.01 & 3467.47 & 12,047.61 \\ LWL\_Si & 3842.25 (\(-16.2\%\)) & 3410.8 (\(-14.6\%\)) & 3111.19 (\(-10.3\%\)) & 10,364.24 (\(-14.0\%\)) \\ \hline \multicolumn{3}{c}{2022} \\ \hline HWL & 4598.28 & 3253.43 & 2179.26 & 10,030.97 \\ HWL\_Si & 3897.24 (\(-15.2\%\)) & 3135.94 (\(-3.6\%\)) & 1260.74 (\(-42.1\%\)) & 8293.92 (\(-17.3\%\)) \\ LWL & 4283.50 & 2710.34 & 1984.71 & 8978.55 \\ LWL\_Si & 3966.99 (\(-7.4\%\)) & 2513.96 (\(-7.2\%\)) & 1497.3 (\(-24.6\%\)) & 7978.25 (\(-11.1\%\)) \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Meadow yield of aboveground biomass in individual plots during the study period (kg\(\cdot\)ha\({}^{-1}\)) [30] and percentage reduction in dry matter after application of the silicon antitranspirant (%).