TVA Fertilizers (IMAGE) IFDC Caption TVA developed 75 percent of the fertilizers used worldwide today -- but research and development in fertilizer technology has almost ceased since the program closed in the early 1990s. Credit IFDC Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.