In a skillet on medium heat, cook the sausage, breaking it into smaller pieces as it cooks. Once cooked through, drain off any excess liquid and place in a slow cooker. Add remaining ingredients, except tomato paste and kale, to the slow cooker. Cook on low for 4 to 6 hours or until the barley is tender. Stir in the tomato paste and kale. Cover and cook on high for 30 minutes or just until the kale has wilted. Serve hot.