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ARS Home » Midwest Area » Ames, Iowa » National Laboratory for Agriculture and The Environment » Soil, Water & Air Resources Research » Research » Publications at this Location » Publication #326357
Title: Corn stover harvest and tillage impacts on near-surface soil physical quality

Author
item TORMENA, CASSIO - University Of Maringa
item Karlen, Douglas
item Logsdon, Sally
item CHERUBIN, MAURICIO - Universidad De Sao Paulo

Submitted to: Soil and Tillage Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/29/2016
Publication Date: 10/3/2016
Citation: Tormena, C.A., Karlen, D.L., Logsdon, S.D., Cherubin, M.R. 2016. Corn stover harvest and tillage impacts on near-surface soil physical quality. Soil and Tillage Research. 166:122-130.

Interpretive Summary: Corn stover has been identified as a potential cellulosic feedstock for production of bioenergy and other bio-products. Harvesting a portion of the residue could be beneficial for both farmers and the bioindustries, but crop residues are also needed to protect the soil from erosion and to supply carbon to maintain soil structure, nutrient cycling, and biological processes. This experiment was conducted to determine the effects of harvesting various amounts of crop residue on the physical quality or condition of a Midwester U.S. soil. Using several different measurements to calculate a least-limiting water range (LLWR) provided more information regarding the effects of tillage and stover harvest on soil structure than individual measurements. This information will be useful to farmers, land managers, conservationists, and soil scientists, because it can be used to identify potential soil physical limitations in areas being harvested for cellulosic feedstock.

Technical Abstract: Excessive harvest of corn (Zea mays L.) stover for ethanol production has raised concerns regarding negative consequences on soil physical quality. Our objective was to quantify the impact of two tillage practices and three levels of corn stover harvest on near-surface soil physical quality through the Least Limiting Water Range (LLWR). We evaluated no harvest, moderate and high stover harvest treatments within no-tillage and chisel plow plots following seven years of continuous corn production. Forty undisturbed soil samples were taken from the 0-7.5 cm deep layer within each treatment and used to determine water retention curves, soil penetration resistance and bulk density values (Bd). No-tillage plots had higher average soil bulk density and penetration resistance values, and were more affected by stover harvest than chisel plow plots. The results confirmed that soil penetration resistance determined the lower limit of the LLWR regardless of tillage or stover treatment, whereas soil aeration controlled the upper limit only at Bd >1.45 and Bd>1.55 Mg m-3 for chisel plow and no-tillage, respectively. The LLWR was smallest for no-tillage with moderate or high corn stover harvest, indicating poor soil physical condition for plant growth, while the largest LLWR occurred with moderate stover harvest and chisel plowing. The introduction of alfalfa (Medicago sativa L.) into an extended rotation with no-tillage improved the LLWR by reducing the potential crop growth restriction due to penetration resistance. Although bulk density values were only occasionally higher than the critical level (Bd=1.60 Mg m-3 for chisel plow and Bd=1.64 Mg m-3 for no-tillage), severe soil structure degradation was evident with no-tillage under moderate or high stover harvest and with chisel plowing under high stover removal. The LLWR was more sensitive than available soil water content for detecting tillage and stover harvest effects on soil structural degradation.