Corn Agronomy Journal • Volume 100, Issue 5 • 2008 1401 Published in Agron. J. 100:1401–1408 (2008). doi:10.2134/agronj2007.0401 Copyright © 2008 by the American Society of Agronomy, 677 South Segoe Road, Madison, WI 53711. All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. D ryland corn production is risky in the south- eastern United States due to intermittent droughts and hot weather during the growing season. Until recently, profit margins limited use of irrigation because of low corn prices and higher production costs. In the past several decades, corn production declined in the southeastern United States as many producers curtailed production to avoid the risk of financial loss. is made the southeastern United States a corn deficit region. In Georgia for example, corn production declined from about 664,000 ha in the 1970s to <121,000 ha in 2006 with significant declines occurring in the 1980s (CAES, 2007a). Renewable bioenergy production has substantially increased the price and demand for corn in the last few years. In response to the enactment of the Renewable Fuels Standard in 2005, mandating the use of 28.4 million m 3 (7.5 billion gallons) of renewable fuel in the United States by 2012 (from about 15.1 million m 3 or 4 billion gallons in 2006), the corn-based etha- nol industry is expanding at an unprecedented rate (Renewable Fuels Association, 2006). As a result, future corn hectares in the United States are soon expected to be at their highest since 1944 (CTIC, 2007). Corn producers in the southeastern United States must overcome the region’s natural limitations of soil and climate to compete for this market. ere is also concern that the rising demand for corn will result in converting marginal lands into corn fields with conventional tillage methods that have proven unsustainable and resulted in degrading natural resources. Many soils in the southeastern United States have low water holding capacity and/or root restrictive layers. Crusting is also a problem because the soils are low in organic matter and this increases runoff from fields. Cecil and related soils exhibit these characteristics and occupy more than half of the 16.7 mil- lion ha Southern Piedmont in the southeastern United States (Radcliffe and West, 2000). Conventional tillage methods, such as disking and harrowing, promote the development of these soil conditions and increase runoff. High residue no-tillage systems have generally been shown to improve soil quality through increased organic matter and infiltration, and reduce runoff and soil loss compared with conventional tillage (Bradley, 1995; Endale et al., 2002b; Fawcett et al., 1994; Langdale et al., 1992; Reeves, 1997; Terra et al., 2005). However, data from peer-reviewed literature estimating the impact of high residue no-tillage manage- ment on corn grown in the Southern Piedmont are limited. Earlier studies in the Piedmont focused on no-tillage corn in sod or grass-based systems. Jones et al. (1968) and Bennett et al. (1973) reported no-tillage corn planted into orchardgrass (Dactylis glomerata L.) sod produced similar or greater yields than corn under conventional tillage. In Georgia, Adams et al. (1970) found that conventionally tilled corn following coastal bermudagrass [ Cynodon dactylon (L.) Pers] or tall fescue (Festuca arundinacea Schreb.) yielded better than no-tillage ABSTRACT Corn (Zea mays L.) producers in the southeastern United States must overcome soil and water limitations to take advantage of the expanding corn market. In this 2001 to 2005 study on a Cecil sandy loam (fine, kaolinitic, thermic Typic Kanhapludult) near Watkinsville, GA, we compared dry land corn biomass and yield under conventional tillage (CT) vs. no-tillage (NT) with ammonium nitrate or sulfate (based on availability) as conventional fertilizer (CF) vs. poultry litter (PL). In a randomized com- plete block split plot design with three replications, main plots were under tillage and subplots under fertilizer treatments. e cover crop was rye (Secale cereale L.). Over 5 yr, NT and PL increased grain yield by 11 and 18%, respectively, compared with CT and CF. Combined, NT and PL increased grain yield by 31% compared with conventionally tilled and fertilized corn. Similarly, soil water was 18% greater in NT than CT in the 0- to 10-cm depth. In 2 yr of measurements, dry matter of stalks and leaves and leaf area index under PL were an average of 39 and 22% greater, respectively, than under CF during reproduction. Values were 21 and 6% greater, respectively, under NT than CT but during tasseling. Analysis of 70 yr of daily rainfall records showed that supplemental irrigation is needed to meet optimal water requirement. Our results indicate that corn growers can use rainfall more efficiently, reduce yield losses to drought, and expect increased corn yields with a combination of no-tillage management and long-term use of poultry litter. D.M. Endale, H.H. Schomberg, D.S. Fisher, M.B. Jenkins, and R.R. Sharpe, USDA-ARS, J. Phil Campbell Sr. Natural Resource Conserv. Center, 1420 Experiment Station Rd., Watkinsville, GA 30677; M.L. Cabrera, Crop and Soil Sciences Dep., Univ. of Georgia, Athens, GA 30602. Received 14 Dec. 2007. *Corresponding author (Dinku.Endale@ars.usda.gov). Abbreviations: CF, conventional fertilizer; CT, conventional tillage; DAP, day aſter planting; LAI, leaf area index; NT, no-tillage; PL, poultry litter. No-Till Corn Productivity in a Southeastern United States Ultisol Amended with Poultry Litter Dinku M. Endale,* Harry H. Schomberg, Dwight S. Fisher, Michael B. Jenkins, Ron R. Sharpe, Miguel L. Cabrera