SEOUL, July 21 (Reuters) - South Korea’s exports in the first 20 days of July jumped 32.8% to $32.58 billion from a year earlier, customs agency data showed on Wednesday. Imports for the same period soared 46.1% on year to $36.52 billion, resulting in a provisional trade deficit of $3.94 billion. Full-month data is due on August 1. (Reporting by Cynthia Kim; Editing by Jacqueline Wong) Our Standards: The Thomson Reuters Trust Principles.