Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: 1/8/2008
Publication Date: 5/27/2008
Citation: Mitchell, C.C., Balkcom, K.S., Delaney, D.P. 2008. Irrigation on the “Old Rotation”. In: Boyd, S., et al, editors. Proceedings of the National Cotton Council Beltwide Cotton Conference, January 8-11, 2008, Nashville, Tenessee.p. 1599-1602.
Interpretive Summary: Researchers from the National Soil Dynamics Laboratory and cooperators from the Agronomy and Soils Department at Auburn University compared irrigation on half of each plot from the Old Rotation starting in 2003 and both irrigated and non-irrigated yields have been monitored since then. Irrigated cotton on the Old Rotation has resulted in a positive yield response in only one year out of five, and that was the severe drought year of 2007. Irrigated yields in 2007 were so dramatically higher than the non-irrigated cotton yields that over the 5-yr period, irrigation resulted in a 22 percent average yield increase over all plots. Irrigation with corn and soybean resulted in higher grain yields each year with average increases of 47 and 44 percent, respectively, over all treatments.
Technical Abstract: The Old Rotation (circa 1896) is the oldest, continuous cotton experiment in the world. Its 13 plots on one acre of land on the campus of Auburn University continue to document the long-term effects of crop rotations with and without winter legumes (e.g., crimson clover) as a source of N for cotton, corn, soybean, and wheat. Irrigation was installed on half of each plot in 2003 and both irrigated and non-irrigated yields have been monitored since then. For more information on the history of the Old Rotation, visit the website at http://www.ag.auburn.edu/agrn/cotton.htm