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ARS Home » Southeast Area » Auburn, Alabama » Soil Dynamics Research » Research » Publications at this Location » Publication #138617
Title: CONSERVATION TILLAGE IN ALABAMA'S "OLD ROTATION"

Author
item MITCHELL, C - AUBURN UNIVERSITY
item Reeves, Donald
item DELANEY, D - AUBURN UNIVERSITY

Submitted to: Southern Conservation Tillage for Sustainable Agriculture Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 6/24/2002
Publication Date: 6/24/2002
Citation: Mitchell, C.C., Reeves, D.W., Delaney, D. 2002. Conservation tillage in alabama's "old rotation". In: Van Santen, E., editor. Proceedings of the 25th Annual Southern Conservation Tillage Conference for Sustainable Agriculture - Making Conservation tillage Conventional: Building a Future on 25 Years of Research. Special Report no. 1, Alabama Agricultural Experiment Station and Auburn University, June 24-26, Auburn, Alabama. p. 30-35.

Interpretive Summary: Questions regarding the impact of farming practices on agricultural sustainability can only be answered by long-term experiments. Alabama's Old Rotation experiment (circa 1896), which tests the sustainability of crop rotation and winter legumes on cotton production, was converted to conservation tillage in 1997 by USDA-ARS cooperators with Auburn University researchers. Since then, record yields of all crops grown on the Old Rotation have been achieved. Long-term yields suggest that winter legumes are just as effective as fertilizer N in producing optimum cotton yields. Yields are highly correlated to soil organic matter levels from cover crop and rotation treatments, as well as conservation tillage. In the past, crop rotation benefits have had a small effect on cotton yields but these benefits are enhanced under conservation tillage. This information can be used by crop consultants and extension and NRCS specialists to show producers the benefits of conservation tillage to increase yields and sustainability, even on severely degraded soils.

Technical Abstract: After 106 cropping years, Alabama's Old Rotation experiment (circa 1896) continues to document the long-term effects of crop rotation and winter legumes on sustainable cotton production in the Deep South. For 100 years the experiment was under conventional tillage. However, since 1997, all crops planted on the Old Rotation have benefitted from conservation tillage. Coincidentally, record yields of all crops grown on the Old Rotation have been achieved since conservation tillage techniques have been implemented. Long-term yields suggest that winter legumes are just as effective as fertilizer N in producing optimum cotton yields. Yields are also highly correlated with soil organic matter that reflect the long-term treatments. In the past, crop rotation benefits have had a small effect on cotton yields, considering yield levels and crop value. These benefits are apparently enhanced under conservation tillage. Soil quality differences, e.g., aggregation and soil tilth, due to rotations and cover cropping are dramatic and are likely to increase under conservation tillage.