It's Yellow Rocket or a close relative thereof. Don't let it seed. If there isn't too much of it, I would pull it by hand. Otherwise mow before it produces seed.
A good rule of thumb for most people is to kill anything in food plots with yellow flowers that comes up in early spring (i.e. Butterweed, Yellow Rocket, Early Wintercress, Buttercups, left over brassicas, etc.....). That advice changes as the year unfolds and beneficial yellow flowered plants like Partridge Pea, Yellow Sweet Clover and Tickseed Sunflower emerge.
