960 SSSAJ: Volume 72: Number 4 • July–August 2008 Funding: USDA NE Sustainable Agriculture Research and Education Program (USDA 2003-3860-12985), Northern NY Agricultural Development Program, Saltonstal family, NSF GK-12 Cornell Science Inquiry Partnerships program (DGE 0231913). Soil Sci. Soc. Am. J. 72:960-969 doi:10.2136/sssaj2007.0248 Received 5 July 2007. *Corresponding author (bnm5@cornell.edu). © Soil Science Society of America 677 S. Segoe Rd. Madison WI 53711 USA 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. Permission for printing and for reprinting the material contained herein has been obtained by the publisher. I nterest in bioenergy production is increasing due to rising concerns about greenhouse gas emissions, increased fuel con- sumption and prices, and a need for higher-value agricultural products to improve agricultural economic viability (Energy Information Administration, 2006; Lal et al., 1998; Mann et al., 2002; Wilhelm et al., 2004). A feasibility study conducted by the Department of Energy (DOE) and the USDA suggested that 30% of the petroleum consumed in the USA could be replaced by using a potential 1 Pg annual supply of biomass (Energy Information Administration, 2006; Perlack et al., 2005). Grains are a common source of biomass, but this diverts prod- ucts from food and feed markets (Perlack et al., 2005; Sanderson, 2006). Crop residues are a potential feedstock source for direct combustion, as well as for bio-refineries using ligno-cellulosic conversion to produce ethanol (Graham et al., 2007; Sanderson, 2006; Werblow, 2006). Maize stover, which makes up more than half of all crop residues in the USA, is by far the most ubiquitous, with an annual availability of approximately 75 Tg (Perlack et al., 2005). However, harvesting crop residues has also been associated with declining soil quality and productivity (Lal, 2005). Soil OM and its dynamics dictate soil structure, which in turn influences other essential physical, chemical, and bio- logical processes (Carter, 2002; Six et al., 1999). Crop produc- tion potential of soils is related strongly to their OM content Bianca N. Moebius-Clune* Harold M. van Es Omololu J. Idowu Robert R. Schindelbeck Dep. of Crop and Soil Sciences Cornell Univ. Ithaca, NY 14853-1901 Daniel J. Moebius-Clune Dep. of Plant Pthology Cornell University Ithaca, NY 14853-1901 David W. Wolfe Dep. of Horticulture Cornell Univ. Ithaca, NY 14853-1901 George S. Abawi Dep. of Plant Pathology New York State Agricultural Experiment Station 630 W. North St. Geneva, NY 14456 Janice E. Thies Dep. of Crop and Soil Sciences Cornell Univ. Ithaca, NY 14853-1901 Beth K. Gugino Dep. of Plant Pathology New York State Agricultural Experiment Station, 630 W. North St. Geneva, NY 14456 Robert Lucey (deceased) Dep. of Crop and Soil Sciences Cornell Univ. Ithaca, NY 14853-1901 SOIL & WATER MANAGEMENT & CONSERVATION Long-Term Effects of Harvesting Maize Stover and Tillage on Soil Quality Rising concerns about greenhouse gases, increased fuel prices, and the potential for new high value agricultural products have raised interest in the use of maize stover for bioenergy produc- tion. However, residue harvest must be weighed against potential negative impacts on soil qual- ity. This study, conducted in Chazy, NY, evaluated the long-term effects of 32 yr of maize (Zea mays L.) stover harvest vs. stover return on soil quality in the surface layer (5–66 mm) under plow till (PT) and no-till (NT) systems on a Raynham silt loam (coarse-silty, mixed, active, nonacid, mesic Aeric Epiaquept) using physical, chemical, and biological soil properties as soil quality indicators. Twenty-five soil properties were measured, including standard chemical soil tests, aggregate stability (WSA), bulk density, (ρ b ) penetration resistance (PR), saturated hydraulic conductivity (K s ), infiltrability (Infilt), several porosity indicators (aeration pores(PO > 1000), soil water potential = Ψ > −0.36 kPa; air-filled pores at field capacity (PO > 30), Ψ > −10kPa; available water capacity (AWC), −1500 < Ψ < −10 kPa), total organic matter (OM), parasitic (Nem parasitic ) and beneficial nematode (Nem beneficial ) populations, decomposition rate (Decomp), potentially mineralizable N (PMN) and easily extractable (EEG) and total glo- malin (TG). Only eight indicators were adversely affected by stover harvest, and most of these effects were significant only under NT. Almost all indicators affected by stover removal were affected equally or more adversely by tillage. A total of 15 indicators were adversely affected by tillage. Results of this study suggest that, on a silt loam soil in a temperate climate, long-term stover harvest had lower adverse impacts on soil quality than long-term tillage. Stover harvest appears to be sustainable when practiced under NT management. Abbreviations: ρ b , bulk density; AWC, available water capacity; Decomp, cellulose decomposition rate; EEG, easily extractable glomalin concentration; K s , saturated hydraulic conductivity; lnK s , ln(K s + 1); Infilt, infiltrability; NT, no-till; NT-H, NT stover harvested; NT-R, NT stover returned; Nem Beneficial , number of beneficial nematodes; Nem Parasitic , number of parasitic nematodes; OM, organic matter; PMN, potentially mineralizable nitrogen; PO > 30, pores with diam. > 30 μm; PO > 1000, pores with diam. > 1000 μm; PR, penetration resistance; PT, plow till; PT-H, PT stover harvested; PT-R, PT stover returned; SOC, soil organic carbon;TG, total glomalin concentration; WSA, water-stable aggregation (0.25–2.00 mm).