菑

Glyph origin
.

Etymology
is r-causative of, both ultimately from  (STEDT)

Possibly same word as "black < color of burnt soil?" 

Definitions

 * 1) one-year-old cropfield

Kanji

 * 1) to weed grass
 * 2) land under cultivation

Hanja

 * 1) to weed grass
 * 2) land which has been under cultivation for one year