沃
ヨウ, ヨク, オク, そそ.ぐ
fertility
JLPT0 G7 S7 F5000
As per
夭
# (slender and limber) +
水
water → *irrigate*; *pour* (← slender stream of water) → *fertile* (← soil made fertile by irrigation).
[Full Kanji Etymology List]