Plant I.D. (Safe to feed sulcata?)

Pretty sure that’s a wild mustard of some kind. Were there any small yellow flowers on the plant? They might not be in bloom yet.

Safe to feed in moderation, if that’s what it is. I’m not sure a sulcata will eat it; my Russian enjoys it in the spring.

For next time, it helps if you also get a picture of the entire plant, still in the ground.