In a blender or food processor, blend or process 1 cup of the water and the tomatoes until smooth.
Transfer to a large saucepan.
Add the remaining 2 cups of water, the carrots, cabbage, split peas, barley, parsley, soy sauce and garlic.
Cover and bring to a boil, then reduce the heat.
Simmer about 1/4 hours or until the barley is tender.