## 3 Results and Discussion
### Sensitivity Analysis
The possible reason for discrepancies in the water balance indicators for CS-3 and CS-4 could be soil composition and variation in the thickness of the soil layers. \begin{table}
\begin{tabular}{l c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Parameters**} & \multicolumn{6}{c}{**Relative Sensitivity Index**} & \multicolumn{6}{c}{**Absolute Sensitivity Index**} \\ \cline{2-13}  & \multicolumn{2}{c}{**NSE**} & \multicolumn{2}{c}{**RSQ**} & \multicolumn{2}{c}{**Yield**} & \multicolumn{2}{c}{**Cum flow**} & \multicolumn{2}{c}{**PBIAS**} & \multicolumn{2}{c}{**RMSE**} \\ \cline{2-13}  & **Sx** & **Rank** & **Sx** & **Rank** & **Sx** & **Rank** & **Sx** & **Rank** & **Sx** & **Rank** & **Sx** & **Rank** \\ \hline CDEG & 0.010 & 6 & 0.009 & 7 & 0.000 & 16 & 0.006 & 7 & 0.696 & 6 & 0.064 & 7 \\ CICE & 0.016 & 4 & 0.016 & 4 & 0.000 & 17 & 0.021 & 1 & 7.523 & 1 & 0.073 & 5 \\
**DC** & 0.011 & 5 & 0.011 & 5 & 0.000 & 4 & 0.000 & 15 & 0.001 & 14 & 0.024 & 9 \\
**Depth\_imp** & 0.000 & 11 & 0.000 & 11 & 0.000 & 6 & 0.001 & 8 & 0.363 & 9 & 0.002 & 14 \\
**Drain depth** & 0.066 & 2 & 0.058 & 2 & 0.053 & 1 & 0.018 & 2 & 6.466 & 2 & 0.158 & 2 \\
**Drain spacing** & 0.129 & 1 & 0.062 & 1 & 0.001 & 3 & 0.001 & 9 & 0.437 & 8 & 0.197 & 1 \\
**Kirk\_depth** & 0.002 & 10 & 0.001 & 10 & 0.000 & 7 & 0.007 & 6 & 2.933 & 4 & 0.023 & 10 \\
**LK1** & 0.000 & 17 & 0.000 & 17 & 0.000 & 12 & 0.000 & 17 & 0.000 & 16 & 0.000 & 16 \\
**LK2** & 0.000 & 12 & 0.000 & 16 & 0.000 & 11 & 0.000 & 14 & 0.000 & 15 & 0.016 & 11 \\
**LK3** & 0.030 & 3 & 0.017 & 3 & 0.023 & 2 & 0.000 & 12 & 0.012 & 13 & 0.099 & 3 \\
**LK4** & 0.000 & 16 & 0.000 & 15 & 0.000 & 10 & 0.000 & 13 & 0.012 & 12 & 0.009 & 12 \\
**LK5** & 0.000 & 15 & 0.000 & 14 & 0.000 & 9 & 0.000 & 10 & 0.145 & 10 & 0.007 & 13 \\
**Slope** & 0.000 & 13 & 0.000 & 12 & 0.000 & 5 & 0.000 & 11 & 0.140 & 11 & 0.000 & 15 \\
**Surf\_storage** & 0.000 & 14 & 0.000 & 13 & 0.000 & 8 & 0.000 & 16 & 0.000 & 17 & & 17 \\
**TKA** & 0.010 & 7 & 0.009 & 6 & 0.000 & 14 & 0.009 & 4 & 0.495 & 7 & 0.073 & 6 \\
**TKB** & 0.003 & 9 & 0.003 & 9 & 0.000 & 15 & 0.008 & 5 & 0.758 & 5 & 0.055 & 8 \\
**ZA** & 0.009 & 8 & 0.009 & 8 & 0.000 & 13 & 0.010 & 3 & 3.756 & 3 & 0.074 & 4 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Compiled LH-OAT sensitivity ranking for CS-3. Field CS-3 had a better drainage design than field CS-4 (Table 1), and the base relative yield was close to 100%. Thus, given the ranges of parameters, other parameters except the drainage design parameter did not significantly impact the relative yield of corn. Though the yield output of corn for 2019 and 2020 differed, the average yield was taken as an indicator of overall corn yield. For CS-3, drain depth, LK3, and drain spacing impacted the corn yield. However, CS-4 needed a better drainage design, so the relative yield could have been higher (average 70%). Also, many other parameters, in addition to drainage design, impacted the yield of corn for this design. Like CS-3, drain depth was the most sensitive parameter influencing relative yield, followed by drain spacing. These are visible in the relative yield plot (Figure 5), where the increase in drain depth and decrease in drain spacing improved the relative yield by up to 100%. Relative yield for CS-4 was also sensitive to the depth of the impermeable layer and lateral hydraulic conductivities of the first, fifth, and fourth layers. Given the inadequate drainage design, lateral conductivities of these layers affected the water logging in these soil layers at the root zone. In both fields, soil temperature parameters were not sensitive to corn's relative yield.