Dedicated Bioenergy Crop Impacts on Soil Wind Erodibility and Organic Carbon in Kansas

Published in Agron. J. 105:1271–1276 (2013) doi:10.2134/agronj2013.0072 Copyright © 2013 by the American Society of Agronomy, 5585 Guilford 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 of environmentally sustainable dedicated energy crops may address concerns about soil and environmental degradation. Dedicated energy crops such as perennial WSGs can be a potential alternative to crop residue removal to provide cellulosic biomass for renewable energy production while improving soil and environmental quality (Blanco-Canqui, 2010). Excessive crop residue removal can adversely affect soil structural stability, SOC pools, water transmission characteristics, soil microbial activity, and other soil properties (Wilhelm et al., 2004; Blanco-Canqui and Lal, 2009). In contrast, perennial WSGs due to their year-round surface cover may protect soil from erosion, improve soil properties, soil productivity, and wildlife habitat and diversity. In addition to their potential as biofuel, perennial WSGs may also serve as a valuable animal feedstock, which is particularly important in years of drought (Craine et al., 2010). In the Great Plains, wind erosion is a major environmental concern. This region witnessed the worst dust storms in United States history during the 1930s (Colacicco et al., 1989). It is well recognized that herbaceous wind barriers can reduce wind erosion, improve crop yield, prevent sandblast damage to crops and trap snow to improve soil moisture (Bilbro and Fryrear, 1988). Similar to wind barriers, plantations of WSGs when grown for forage and biofuel may be an effective management practice to reduce wind erosion. Perennial WSGs provide permanent vegetative cover which can adsorb wind energy, reducing wind velocity (Bilbro and Fryrear, 1997). Extensive and deep root systems under perennial WSGs may also stabilize and anchor soil, increasing soil aggregate size and stability. In the Great Plains, wind erosion is usually the greatest between February and May when winds are strong and crops are sparse or not present to protect the soil surface. Presence of dormant WSGs in early spring may reduce wind erosion compared with row crops with limited surface residue cover. Bilbro and Fryrear (1997) concluded that tall and lodge-resistant plants, such as switchgrass, increased the effective distance of wind barriers. Grasses are able to absorb blowing soil particles and reduce the loss of windblown materials (Bilbro and Fryrear, 1997). Current research on dedicated bioenergy crops mostly focuses on increasing production of biomass (Propheter et al., 2010). As a result, data on dedicated bioenergy crop impacts on soil and water conservation, soil physical properties, SOC dynamics, and other soil and environmental factors are limited, particularly in Kansas. This information is, however, needed to assess the potential benefits of growing dedicated energy crops under different regions. Benefits for WSGs for improving soil properties may be inconsistent, depending on the length of management, grass species, soil type, and climate (Schwartz et al., 2003). Most dedicated bioenergy crops are expected to be grown in marginal lands to reduce concerns over competition for land with prime agricultural production (Kort et al., 1998; Cai et al., 2011). Throughout the central Great Plains in general and ABSTRACT