Impact of Previous Cover Crops and Corn Stover Removal on Soil Organic Carbon, Aggregate Stability and Squash Yield

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Date

2015-01-07

Authors

Ouellette, Lance

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Publisher

University of Guelph

Abstract

Corn stover removal for biofuel production can have a negative effect on crop yield and/or soil quality. Cover crops may offer an opportunity to improve or maintain soil quality within corn stover removal systems. This research assessed the effects of cover crops systems and corn stover removal on soil aggregate stability, squash (Cucurbita pepo var. pepo cv. Autumn Delight) fruit yield, and soil carbon and nitrogen dynamics. Diffuse reflectance infrared Fourier-transform (DRIFT) spectroscopy was used to semi-quantitatively assess soil organic matter decomposition from soil amended with oat (Avena sativa L.), cereal rye (Secale cereale L.), oilseed radish (Raphanus sativus L. var. oleoferus Metzg. Stokes) (OSR), and a mixture of oilseed radish and cereal rye (OSR+rye), with and without corn stover by measuring polysaccharide-C bands regularly over a 72 d incubation study, and comparing first-order model parameters to evolved C. One year after corn stover removal in cover crop systems there were no differences in soil aggregate stability and clay dispersibility. Squash vegetable yield was also not affected by corn stover removal after one year. Results showed that all cover crop-corn stover treatment combinations had a significantly lower polysaccharide decomposition and C mineralization rates compared to the no cover treatment. Thus, although subsequent crop yield was not impacted, this study suggests that these cover crops, in particular OSR and OSR+rye, have the potential, in the short-term, to replenish labile organic C pools and to reduce C losses when compared to the no cover control treatment.

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Keywords

Corn stover removal, Cover crops, Soil quality, Squash, Crop yield

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