1. Old photograph useful as a tool in precision ag Collection: Agricultural Communications Documentation Center (ACDC) Contributers: Thomas, Robert (author) Format: Journal article Publication Date: 2008-02 Published: USA Location: Agricultural Communications Documentation Center, Funk Library, University of Illinois Document Number: C26968 Journal Title: Prairie Farmer Journal Title Details: 180(2) : 32 Notes: Aerial photographs of farms over time (1939, 1962, 1968 and 1995 in this case example) help reveal reasons for yield variability and help guide farmers in making decisions.