Wayne, For a history of the US Farm Bill and conservation, McGranahan et al. (2013) is an excellent place to start.
Devan A. McGranahan, Paul W. Brown, Lisa A. Schulte, and John C. Tyndall. 2013. A historical primer on the US farm bill: Supply management and conservation policy. Journal of Soil and Water Conservation 68(3):67A-73A. doi:10.2489/jswc.68.3.67A Contact me or any of the authors off list if you are not able to access a copy of the article. Best, Todd
