expression, godan verb (-tsu)
do something stupid; do something pointless
Rare idiomatic expression literally meaning 'to hit a muddy rice field with a stick'. Used to describe a futile or foolish action, similar to 'beating a dead horse'.
そんなことをするのは泥田を棒で打つようなものだ。
Doing that is like beating a dead horse.
The expression is a vivid metaphor: hitting a muddy rice field with a stick achieves nothing useful, hence the idiomatic meaning of a pointless or stupid action.