# Optimal Design and Experiment of Corn-Overlapped Strip Fertilizer Spreader
## 3 Simulation Test of Corn-Overlapped Strip Fertilizer Spreader
### Parameter Optimization Test
#### 3.3.2 Response Surface Simulation Test  
The single-factor test results showed that the angle \(\alpha\), width \(N\), and height \(H\) had significant effects on the transversal fertilizer uniformity coefficient and longitudinal fertilizer uniformity coefficient. To further optimize the fertilizer spreading performance, the degree of influence of the above factors and their interaction terms were investigated, and the ternary orthogonal rotational combination response surface simulation test was carried out with angle \(\alpha\), height \(H\), and width \(N\) as test factors, denoted by \(X_{1}\), \(X_{2}\), and \(X_{3}\), respectively, and the transversal fertilizer uniformity coefficient \(Y_{1}\) and longitudinal fertilizer uniformity coefficient \(Y_{2}\) as test indexes. The test factor code table is shown in Table 3, the simulation results and the test protocol table are shown in Table 4, and the analysis of variance is shown in Tables 5 and 6. \begin{table}
\begin{tabular}{c c c c} \hline
**Test Factors** & **Range of Test Factors** & \
\begin{tabular}{c} **Transversal Fertilizer** \\ **Uniformity Coefficient \(Y_{1}\)** \\ \end{tabular} &
\begin{tabular}{c} **Longitudinal Fertilizer** \\ **Uniformity Coefficient \(Y_{2}\)** \\ \end{tabular} \\ \hline \multirow{4}{*}{Angle \(\alpha\)} & 30\({}^{\circ}\) & 0.7901 & 0.4293 \\  & 37.5\({}^{\circ}\) & 0.7024 & 0.3290 \\  & 45\({}^{\circ}\) & 0.6190 & 0.2213 \\  & 52.5\({}^{\circ}\) & 0.6226 & 0.2127 \\  & 60\({}^{\circ}\) & 0.5828 & 0.1356 \\ \hline \multirow{4}{*}{Width \(N\)} & 250 mm & 0.8902 & 0.5160 \\  & 300 mm & 0.8298 & 0.4489 \\  & 350 mm & 0.8139 & 0.4356 \\  & 400 mm & 0.7793 & 0.4112 \\  & 450 mm & 0.7105 & 0.28952 \\ \hline \multirow{4}{*}{Height \(H\)} & 40 & 0.8137 & 0.4351 \\  & 45 & 0.7402 & 0.3296 \\ \cline{1-1}  & 50 & 0.6190 & 0.2213 \\ \cline{1-1}  & 55 & 0.597 & 0.1850 \\ \cline{1-1}  & 60 & 0.5912 & 0.2168 \\ \hline \end{tabular}
\end{table} 
Table 2: Single factor test results of swing angle, height, and width. Figure 9: The influence curve of the single factor test. (**a**) Effect of angle on the transversal fertilizer uniformity coefficient and longitudinal fertilizer uniformity coefficient, (**b**) effect of width on the transversal fertilizer uniformity coefficient and longitudinal fertilizer uniformity coefficient, (**c**) effect of height on the transversal fertilizer uniformity coefficient and longitudinal fertilizer uniformity coefficient. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multicolumn{5}{c}{**Test Factor**} & \multicolumn{3}{c}{**Test Indexes**} \\ \cline{2-5} \multicolumn{1}{c}{**Code**} & \multicolumn{1}{c}{**Angle \(X_{1}\)/(\({}^{\circ}\))**} & \multicolumn{1}{c}{**Height \(X_{2}\)/mm**} & \multicolumn{1}{c}{**Width \(X_{3}\)/mm**} & \multicolumn{1}{c}{**The Transversal Fertilizer**} & \multicolumn{1}{c}{**The Longitudinal Fertilizer**} \\ \cline{2-5} \multicolumn{1}{c}{**Uniformity Coefficient \(Y_{1}\)**} & \multicolumn{1}{c}{**Uniformity Coefficient \(Y_{2}\)**} \\ \hline
1 & 52.50 & 400.00 & 55.00 & 0.1763 & 0.1129 \\
2 & 56.9  
The variance of the model the of transversal fertilizer uniformity coefficient \(Y_{1}\) is shown in Table 5. The model was highly significant, the significance test of the model \(F_{1}=4.44\), \(p<0.01\), and the misfit term was not significant \(F_{2}=9.38\), \(p>0.01\), indicating that the regression model is highly significant and fits well within the test. The effects of angle \(X_{1}\), height \(X_{2}\), and width \(X_{3}\) were significant (\(0.01<p<0.05\)), the interaction term \(X_{1}X_{3}\) had an effect (\(0.05<p<0.1\)), \(X_{3}{}^{2}\) had an extremely significant effect (\(p<0.01\)), and the remaining terms did not have a significant effect on this test index (\(p>0.1\)).