Why does my dog eat dirt. She does not do this all the time but occasionally she goes out in the yard and eats dirt?

It could be something she's missing in her diet, it could be a behavioral issue, but you need to do all you can to stop her from doing this because there are fungal spores called Coccidiodiomycosis that dogs can contract. The fungus can settle in the joints, the respiratory tract, or I've seen it settle in both, it takes many months of expensive treatment to cure. But if your dog still has the habit she can contract it again, I would discuss this with your vet along with her diet and see if together you can't cone up with a solution. Good luck to you.

It is a habit of dogs ,Hold a stick just to scare him away from the yard dirt and gradually by pratice it will refrain from doing so.. Observe if the dog is eating grass or dirt,if it is eating grass the meaning is its stomach is upset (loose motion or indigestion),you then have to give him curds which binds the motion

Your dog is lacking minerals.

Al least she doesn't eat sh!t.