A five-volume color slide series providing detailed knowledge on fertilizer improvement. Stored for a long time at my parents' house, there is age-related soiling on the covers, etc., but all the slides are present. The sound on the cassettes has not been confirmed as I don't have a deck. - Series Name: Fertilizer Improvement Series - Volumes: 5 volumes total - Title: Growth Disorders and Fertilization - Publisher: Rural Culture Association Japan - Format: Color Slides