Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/8/2008
Publication Date: 9/10/2008
Citation: Endale, D.M., Schomberg, H.H., Fisher, D.S., Jenkins, M., Sharpe, R.R., Cabrera, M.L. 2008. No-till corn productivity in a Southeastern United States ultisoil amended with poultry litter. Agronomy Journal. 100:1401-1408.
Interpretive Summary: In the past several decades, corn production declined in the southeastern United States due to climate and soil-related limitations coupled with low corn prices. In Georgia, for example, corn acreage declined from average of 1.64 million acres in the 1970s to about 300,000 acres in 2006. Adoption of no-tillage and use of poultry litter as an alternative to conventional fertilizers might help corn producers overcome some of these limitations and boost corn production. In this 2001-2005 study, scientists at the USDA-ARS, J. Phil Campbell Sr., Natural Resource Conservation Center, Watkinsville, GA, and Crop and Soil Sciences Department, University of Georgia in Athens, GA, compared non-irrigated corn production under two tillage systems (conventional tillage and no-tillage) and two fertilizer sources (conventional mineral fertilizer, and poultry litter). Rye was grown in fall through early spring as a cover crop for both tillage systems. Over five years no-tillage increased grain production by 11% compared to conventional tillage and poultry litter increased yield 18% compared to conventional fertilizer. However, the combination of no-tillage and litter increased yield 31% compared to corn grown with conventional tillage and conventional fertilizer. The increased grain yield was in part due to greater soil water conservation in the no-tillage system. The increasing price and demand for corn, related to the unprecedented increase of the corn-based ethanol industry, might result in the conversion of marginal land into cornfields with conventional tillage methods that have proven unsustainable and resulted in natural resource degradation. Our research results indicate growers can conserve and use rainfall more efficiently, reduce the risk of yield-limiting droughts, and expect increased corn yields with no-tillage and poultry litter. In 2004 about 4.7 million acres of corn was planted in the Southeast. Growers, extension agents, local, state and federal agencies involved in improving crop productivity, natural resource protection and alternative fuel sources would find these results useful.
Technical Abstract: The emerging potential for large-scale renewable bio-energy production has substantially increased the price and demand of corn (Zea mays L.). In order to compete in the new corn market producers in the southeastern USA need to overcome the region’s soil and water limitations. One option is adopting no-tillage corn production with relatively inexpensive poultry litter as a nutrient source. In this 2001-2005 study on a Cecil soil (fine, kaolinitic thermic Typic Kanhapludult) near Watkinsville, GA, we compared corn biomass and yield under two tillage (conventional tillage, CT versus no-tillage, NT) and two N sources (ammonium nitrate or sulfate as conventional fertilizer, CF, versus poultry litter, PL). The experiment was a randomized complete block split plot design with three replications. The main plots were tillage treatments and subplots were N source treatments. Rye (Secale cereale L.) was used as a cover crop for both tillage treatments. During the five year experiment, no-tillage increased grain yield by 11% compared to CT and poultry litter increased yield by 18% compared to CF. No-tillage and litter combined increased grain yield by 31% over five years compared to conventionally tilled and fertilized corn. No-tillage and litter also increased dry matter production through the cropping season compared to CT and CF. In two years of measurements, dry matter of stalks and leaves was an average of 39% and leaf area index 22% greater in the litter than CF treatment during the reproduction phase. For no-tillage values were 21 and 6%, respectively, but around tasseling. Over five years, soil water in no-tillage in the 0-10 cm depth was greater by 18% compared to that in CT. Environmental and management factors led to substantial year to year grain yield variability. Our results indicate that growers can utilize rainfall more efficiently, reduce yield losses to drought, and expect increased corn yields with a combination of no-tillage management and use of poultry litter.