# Controlled Drainage Effectiveness in Reducing Nutrient Outflow in Light of Climate Changes
## 3 Results
### Effect of CD on Quality Drainage Outflow
The highest reduction close to 100% of NO3-N and PO4 loads was shown for the CD application on 1 March (Table 8) for all GFDL, MPI, and UKESM models. Also, for the MPI model, starting the withholding of outflow on 15 March shows reductions of 85% or more, for wet, normal, and dry years. Starting CD practice on 1 April and 15 April shows a much lower or no reduction. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{\
\begin{tabular}{c} **Drainage** \\ **Variants** \\ \end{tabular} } & \multirow{2}{*}{
\begin{tabular}{c} **Initial GWT** \\ **(cm b.s.l.)** \\ \end{tabular} } & \multicolumn{5}{c}{**Load NO3-N (kg ha\({}^{-1}\))**} \\ \cline{3-8}  & & & **Wet** & & **Normal** & **Dry** \\ \hline \multicolumn{8}{c}{MPI} \\ \hline \multirow{3}{*}{FD} & 40 & 30.35 & k, l & 27.23 & i, j & 24.61 & m \\  & 60 & 23.30 & g, h, i, j, k, l & 20.21 & g, h, i, j & 17.67 & h, i, j, k, l, m \\  & 80 & 15.80 & c, d, e, f, g, h & 12.75 & d, e, f, g & 10.33 & b, c, d, e, f, g, h \\ \hline \multirow{3}{*}{CD} & 40 & 0.47 & a & 0.44 & a, b & 0.41 & a \\  & 60 & 0.38 & a & 0.32 & a, b & 0.28 & a \\  & 80 & 0.24 & a & 0.20 & a, b & 0.16 & a \\ \cline{2-8}  & 40 & 5.58 & a, b, c & 2.71 & a, b, c, d & 2.08 & a, b, c, d \\  & 60 & 2.54 & a, b & 1.20 & a, b, c & 1.14 & a, b, c \\  & 80 & 0.91 & a & 0.42 & a, b & 0.62 & a, b \\ \hline \multirow{3}{*}{CD} & 40 & 29.79 & j, k, l & 26.82 & i, j & 23.23 & l, m \\  & 60 & 22.74 & g, h, i, j, k, l & 19.81 & g, h, i, j & 16.35 & g, h, i, j, k, l, m \\  & 80 & 15.25 & c, d, e, f, g, h & 12.35 & c, d, e, f, g & 9.14 & a, b, c, d, e, f, g, \\ \hline \multirow{3}{*}{15.04} & 40 & 30.35 & k, l & 27.23 & i, j & 24.60 & m \\  & 60 & 23.30 & g, h, i, j, k, l & 20.21 & g, h, i, j & 17.66 & h, i, j, k, l, m \\  & 80 & 15.80 & c, d, e, f, g, h & 12.75 & d, e, f, g & 10.32 & b, c, d, e, f, g \\ \hline \multicolumn{8}{c}{UKESM} \\ \hline \multirow{3}{*}{FD} & 40 & 26.65 & i, j, k, l & 29.49 & j & 21.67 & k, l, m \\  & 60 & 19.58 & e, f, g, h, i, j & 22.43 & g, h, i, j & 14.74 & f, g, h, i, j, k, l \\  & 80 & 12.03 & b, c, d, e, f & 14.88 & e, f, g, h & 7.50 & a, b, c, d, e, f, g \\ \hline \multirow{3}{*}{CD} & 40 & 0.51 & a & 0.45 & a, b & 0.41 & a \\  & 60 & 0.35 & a & 0.33 & a, b & 0.27 & a \\  & 80 & 0.21 & a & 0.21 & a, b & 0.14 & a \\ \hline \multirow{3}{*}{CD} & 40 & 20.01 & f, g, h, i, j, k & 20.03 & g, h, i, j & 17.38 & h, i, j, k, l, m \\  & 60 & 13.31 & c, d, e, f, g & 13.36 & d, e, f, g & 10.75 & c, d, e, f, g, h, i \\  & 80 & 6.36 & a, b, c, d & 6.50 & a, b, c, d, e & 4.06 & a, b, c, d, e \\ \hline \multirow{3}{*}{CD} & 40 & 23.72 & g, h, i, j, k, l & 25.77 & h, i, j & 20.29 & i, j, k, l, m \\  & 60 & 16.71 & d, e, f, g, h, i & 18.78 & g, h, i, j & 13.41 & e, f, g, h, i, j, k, l \\  & 80 & 9.25 & a, b, c, d, e & 11.44 & b, c, d, e, f, g & 6.31 & a, b, c, d, e, f \\ \hline \multirow{3}{*}{15.04} & 40 & 24.72 & h, i, j, k, l & 27.35 & i, j & 20.38 & i, j, k, l, m \\  & 60 & 17.10 & e, f, g, h, i & 20.35 & g, h, i, j & 13.49 & e, f, g, h, i, j, k, l \\  & 80 & 10.23 & a, b, c, d, e, f & 12.95 & d, e, f, g & 6.37 & a, b, c, d, e, f \\ \hline \hline \end{tabular}  
Notes: Different letters (a to l) indicate significant differences (\(p\leq 0.05\)) between variants for each group of years, according to [PERSON]’s test.  
\end{table} 
Table 6: _Cont._  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{\ \begin{tabular}{c} **Drainage** \\ **Variants** \\ \end{tabular}  } & \multirow{2}{*}{ \begin{tabular}{c} **Initial GWT** \\ **(cm b.s.l.)** \\ \end{tabular}  } & \multicolumn{5}{c}{**Load PO4 (kg ha\({}^{-1}\))**} \\ \cline{3-7}  & & & & & **Normal** & & **Dry** \\ \hline \hline \multicolumn{7}{c}{GFDL} \\ \hline FD & & 40 & 1.25 & 1 & 0.85