Submitted to: Soil Science Society of America Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/22/2005
Publication Date: 1/25/2006
Citation: Blanco-Canqui, H.R., Lal, R., Post, W.M., Izaurralde, R.C., Owens, L.B. 2006. Corn stover impacts on near-surface soil properties of no-till corn in Ohio. Soil Science Society of America Journal. 70:266-278. Interpretive Summary: Some crops, such as corn, produce a lot of residue. In some areas this residue is completely or partially removed to be used as a “feedstock” for biofuels. Because biofuels reduce the dependence on fossil fuels, there may be more use of plant residues for this purpose. Another side of this issue is whether residue removal has impacts on soil. This study at three locations in Ohio evaluates the impacts on soil properties with different levels of corn residues. Plots were established with 0%, 25%, 50%, 75%, 100%, and 200% of normal corn stover remaining on the plot. The soil properties studied included bulk density, cone index (a measure of compaction), shear strength (a soil strength property) and volumetric moisture content. The results showed that complete removal of corn residue leads to rapid deterioration of soil strength properties and reduction of soil moisture in no tillage corn systems. Compaction also increased. With 75% or more retention of corn stover, soil strength properties, compaction, bulk density, and soil moisture content in no tillage soils were not greatly impacted. Thus, perhaps up to 25% of corn residue can be removed from no tillage corn systems without detrimental soil impacts. This information is important for land managers and producers as well as biofuel industry planners.
Technical Abstract: Corn (Zea mays L.) stover is a primary feedstock for biofuel production to reduce over-reliance on fossil fuels and reduce net CO2 emissions. While use of corn stover as biofuel is beneficial, excessive stover removal may negatively impact soil physical quality. This study assessed changes in soil strength and moisture resulting from a systematic removal of stover from three Ohioan soils under no-till (NT) continuous corn. On-going experiments at North Appalachian Experimental Watersheds (NAEW), Western Agricultural Experiment Station (WAES), and Northwestern Agricultural Experiment Station (NWAES) of Ohio Agricultural Research and Development Center (OARDC) were used for this study. Six stover retention rates of 0 (T0), 25 (T25), 50 (T50), 75 (T75), 100 (T100), and 200 (T200) % were imposed in 3 x 3 m plots corresponding to 0, 1.25, 2.50, 3.75, 5.00, and 10.00 Mg ha-1 of stover, respectively. Bulk density (b), cone index (CI), shear strength (SHEAR), and volumetric moisture content (ÿv) were measured monthly from June through Dec, 2004. Removal of stover increased b, CI, SHEAR, and reduced ÿv (P<0.05). Magnitude of decrease in b with increase in stover retention from T0 to T200 was higher at NAEW (1.34 vs. 1.18 Mg m-3) and NWAES (1.34 vs. 1.19 Mg m 3) than at WAES (1.38 vs. 1.29 Mg m-3). Differences in soil strength properties among T75, T100, and T200 were mostly small. The ÿv was unaffected by stover removal in Nov and Dec. Differences in b were significant early in the experiment at all but WAES site, showing that treatment effects depended on site and sampling date. Excessive removal of corn stover can cause rapid and significant soil compaction, but further long-term monitoring of soil properties is needed to define threshold levels of removal.