Where the shape comes from
A forked wooden plough, the handle branching at the top into the grip a farmer’s hands would close around, the curved share below it breaking the soil. Set beside 井, a well, or the grid lines of a field, it gives 耕, to plough, to cultivate, the plough shown at work on land marked out in squares.
汉字 filed under 耒
No published character on HSK Guide is filed under this radical yet. 汉字库.