In a large bowl, combine ground turkey, egg, breadcrumbs, parsley, garlic powder, salt and pepper. Mix with a wooden spoon or clean hands until well combined. Roll the mixture into 1-inch meatballs, forming about 20 to 22 meatballs.
Heat 1 tablespoon olive oil in a large skillet over medium heat. Cook meatballs until browned, about 3 to 4 minutes. Drain on a paper towel-lined plate and set aside.
Add remaining olive oil to a large Dutch oven or stockpot. Add garlic, onions, carrots and celery, and cook until the vegetables are tender, about 5 minutes.
Stir in chicken stock, barley, bay leaf, Parmesan rind, and meatballs. Bring to a boil then simmer until meatballs are cooked through and the soup is slightly thickened, about 15 minutes. Stir in chopped kale until wilted, about 2 minutes. Serve immediately.