This is an actual (somewhat) working reupload of Aedonthorn's mod on Nexus

As of version 1.0.12 of the game, it works fine with some minor downsides (check changelog).

Info

This mod allows you to modify the size of the land affected by the hoe by holding down an optional modifier key (default: Left Alt) and scrolling with the mouse, or by pressing one of two customizable hotkeys (default: disabled).

You can also adjust the increment values and hotkeys in the config file.