A plow drawn by a work animal makes a huge difference compared to mere handheld tools, but is still less efficient than modern farm machinery. It adds a significant bonus (around +40%) to the outcome of all crops harvested. This tool bonus is cumulative with those from other tools and is listed on the annual report.
The Angry Mob event causes the player to lose all his tools, including plows.
In a Civil War there’s a 75% risk that each plow will be lost or destroyed.
“History of the Plow” by Mary Bellis, ThoughtCo, 2019: