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Title: Continued support of long-term research - cullars rotation

item MITCHELL, C - Auburn University
item DELANEY, D - Auburn University
item Balkcom, Kipling

Submitted to: Agricultural Experiment Station Publication
Publication Type: Experiment Station
Publication Acceptance Date: 7/18/2013
Publication Date: 1/13/2014
Citation: Mitchell, C., Delaney, D., Balkcom, K.S. 2014. Continued support of long-term research - cullars rotation. Cotton Research Report, Alabama Agricultural Experiment Station, Report No. 43. p. 30. Available at

Interpretive Summary:

Technical Abstract: The Cullars Rotation (circa 1911) is the oldest continuous soil fertility study in the Southern U.S. In commemoration of the 2011 Centennial Year for this experiment, a comprehensive Alabama Agricultural Experiment Station bulletin was published covering the first 100 years of this experiment. ( A poster was also presented at the 2012 Beltwide Cotton Conference. This study is non-irrigated and yields reflect growing conditions during the season. Note the dramatic yield response to added K by cotton. Highest cotton yields (1,493 pounds lint/acre) were produced on the treatment receiving a complete fertilizer plus micronutrients (boron). No added P (Plot 2) dramatically reduces wheat and corn yields more than cotton yields. Soybean yields are equally affected by P and K deficiencies. All fertilizers are applied to the cotton and wheat crops. The Cullars Rotation Experiment is an excellent site to see dramatic nutrient deficiencies compared to healthy crops each year. This type of comparison does not exist anywhere else in the USA.