\documentclass[tikz]{standalone}
\usepackage{etoolbox}
\usetikzlibrary{calc}

\begin{document}

\begin{tikzpicture}[
    x=9mm,
    y=9mm,
    line cap=round,
    line join=round
]

\input{figure_base.tex}

\GrassField{10}{6}

\CornerFence{3}{5}{NE}
\CornerFence{5}{5}{NE}
\CornerFence{7}{5}{NE}

\CornerFence{1}{3}{SW}
\CornerFence{9}{3}{SE}

\CornerFence{3}{1}{SE}
\CornerFence{5}{1}{SE}
\CornerFence{7}{1}{SE}


\foreach \i in {2,...,7} {
    \foreach \j in {2,...,3} {
        \GrassCell{\i}{\j}{20}
    }
}

\end{tikzpicture}

\end{document}