Long-term tillage and poultry litter application impacts on crop production in northeastern Alabama

Authors: Watts, Dexter; Torbert, Henry - Allen

Submitted to: Southern Conservation Agricultural Systems Conference
Publication Type: Proceedings
Publication Acceptance Date: 7/20/2010
Publication Date: 7/20/2010
Citation: Watts, D.B., Torbert III, H.A. 2010. Long-term tillage and poultry litter application impacts on crop production in northeastern Alabama. In: Conservation Agriculture Impacts-Local and Global, Proceedings of the 32nd Southern Conservation Agricultural Systems Conference, July 20-22, 2010, Jackson, Tennessee. p.49-53.

Interpretive Summary: Tillage, manure and crop rotation practices can impact crop yield. Our work evaluated corn grain yield from 1991 through 2001 in the Sand Mountain region of Northeast Alabama. The tillage practices were no-till, chisel tillage, and conventional tillage and the manure type was poultry litter. This study evaluated the yield of continuous corn with a wheat cover crop and corn with a wheat cover crop rotated with soybean with a wheat cover. Poultry litter was used to fertilizer the winter wheat cover only. Cover crops not receiving poultry litter received inorganic fertilizer. Corn yield was impacted by tillage with conventional tillage producing a higher grain yield during most years. Fertilizing the cover crop with poultry litter also increased the amount grain produced compared to the use of standard inorganic fertilizer. Use of a soybean crop rotation with corn had the greatest impact on grain production. Thus, suggesting that rotation between crops should be incorporated into production systems to maintain sustain grain yields.

Technical Abstract: Conservation tillage, manure application, and crop rotations are thought to increase yields compared to conventional monoculture (continuous cropping system without rotation) tillage systems. The objective of this study was to evaluate cropping sequences of corn with a wheat cover crop and corn with a wheat cover crop following a soybean rotation in conventional, strip, and no-tillage systems with poultry litter additions to the wheat cover crop. Thus, a field study was conducted at the Sand Mountain Substation in the Appalachian Plateau region of Northeast Alabama, USA, on a Hartselle fine sandy loam (fine-loamy, siliceous, subactive, thermic Typic Hapludults). In 1980, the corn cropping systems were initiated with three different tillage treatments (conventional, strip, and no-tillage). Poultry litter treatments were added in 1991. Poultry litter was applied in the fall of each year to the wheat cover crop at a rate of 50 lb N acre- 1. Wheat not receiving poultry litter received an equal amount of inorganic N. The corn crop was fertilized in the spring with 50 lbs N acre-1 at planting followed by 150 lbs N acre-1 applied approximately 3 weeks following emergence. Corn grain yields were influenced by tillage in 1991, 1992, 1993, 1994, 1996, 1997, 1998, and 2001 with conventional tillage producing the greatest yields except in 1993 (strip tillage) and 2001 (no-till). Increases in grain yield from poultry litter addition were observed in 1991, 1997, and 1998. Crop rotation increased corn grain yield in all years except 2001. Corn crops following soybean rotation provided the most consistent yield increase for the 9 yr study. Thus suggesting, crop rotations should be implemented into corn production systems in order to produce sustainable crop production.