The laws concerning the recitation of Berachot when eating vegetable soup depend on how the soup was prepared:
1) If the soup consists only of liquid which was boiled with vegetables to absorb their flavor, after which the vegetables were removed, one recites the Beracha of "She'hakol." Since one drinks only liquid, no Beracha other than "She'hakol" is required.
2) If, however, the vegetables were left in the soup, and thus one eats both broth and vegetables, he must recite two Berachot: "Borei Peri Ha'adama" on the vegetables, followed by "She'hakol" on the broth. Although normally when foods are eaten together one recites only the Beracha over the majority food, this Halacha applies only when the foods are mixed together. In a vegetable soup, however, the vegetables and liquid remain as separate entities, and do not blend into a mixture. Therefore, one must recite separate Berachot over the vegetables and over the soup. This is the ruling of Rabbi Moshe Halevi, in his work Birkat Hashem (vol. 3, 10:41).
3) Finally, if the vegetables were left in the soup but were diced, such that each spoonful will likely contain both liquid and vegetables, then we indeed treat the soup as a mixture of vegetable and broth. As such, the Beracha is determined based on the majority component: if the soup contains more broth than vegetables, then one recites "She'hakol"; if the soup contains more vegetables than broth, one must recite "Borei Peri Ha'adama." Since this soup is treated as a mixture, the Beracha is determined based on the majority component.
Summary: The Beracha over vegetable soup consisting of only liquid is "She'hakol." If the soup contains pieces of vegetables, then one recites "Ha'adama" over the vegetables and "She'hakol" over the liquid. If the vegetables are diced such that each spoonful contains both liquid and vegetables, then one recites "Ha'adama" if there are more vegetables than liquid, and "She'hakol" if there is more liquid than vegetables.
