"The farm bill provides an opportunity for Congress to address agricultural and food issues comprehensively about every five years. Over time, farm bills have tended to become more complicated and politically sensitive. As a result, the timeline for reauthorization has become less certain, and in general recent farm bills have taken longer to enact than in previous decades. Recent farm bills, beginning with the 2008 farm bill (P.L. 110-246), have been subject to various developments that have delayed enactment, such as insufficient votes to pass the House floor, presidential vetoes, and short-term extensions. The 2014 farm bill took more than 21 months from introduction to enactment and spanned the 112th and 113th Congresses. The House rejected a bill in 2013 and then passed separate farm and nutrition assistance components before procedurally recombining them for conference with the Senate. Somewhat similarly, the 2008 farm bill took more than a year to enact and was complicated by revenue provisions from another committee of jurisdiction, temporary extensions, and vetoes."
CRS Report for Congress, R45210