{
\def\sym#1{\ifmmode^{#1}\else\(^{#1}\)\fi}
\begin{tabular}{l*{1}{c}}
\toprule
                    &\multicolumn{1}{c}{(1)}\\
                    &\multicolumn{1}{c}{Yield (kg/ha)}\\
\midrule
Fertilizer (kg/ha)  &       1.318\sym{**} \\
                    &     (0.599)         \\
\addlinespace
Total labor for growing (day/ha)&       2.490         \\
                    &     (5.195)         \\
\midrule
Observations        &         739         \\
R-squared           &       0.030         \\
\bottomrule
\multicolumn{2}{l}{\footnotesize Standard errors in parentheses}\\
\multicolumn{2}{l}{\footnotesize \sym{*} \(p<0.10\), \sym{**} \(p<0.05\), \sym{***} \(p<0.01\)}\\
\end{tabular}
}
