Page Banner

United States Department of Agriculture

Agricultural Research Service

Research Project: SOIL AND CROP MANAGEMENT SYSTEMS FOR IMPROVED NATURAL RESOURCE QUALITY AND EFFICIENCY

Location: North Central Agricultural Research Laboratory

Title: Soil microbial community response to corn stover harvesting under rain-fed, no-till conditions at multiple U.S. locations

Authors
item Lehman, R
item Ducey, Thomas
item Jin, Virginia
item Acosta-Martinez, Veronica
item Ahlschwede, Carla
item Jeske, Elizabeth -
item Drijber, Rhae -
item Cantrell, Keri
item Frederick, James -
item Borkowski, Darci
item Osborne, Shannon
item Novak, Jeffrey
item Johnson, Jane
item Varvel, Gary

Submitted to: BioEnergy Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 14, 2014
Publication Date: April 28, 2014
Citation: Lehman, R.M., Ducey, T.F., Jin, V.L., Acosta Martinez, V., Ahlschwede, C.M., Jeske, E.S., Drijber, R.A., Cantrell, K.B., Frederick, J.R., Borkowski, D.M., Osborne, S.L., Novak, J.M., Johnson, J.M., Varvel, G.E. 2014. Soil microbial community response to corn stover harvesting under rain-fed, no-till conditions at multiple U.S. locations. BioEnergy Research. 7:540-550.

Interpretive Summary: Harvesting of corn stover for cellulosic ethanol production must be balanced with the requirement for returning plant residues to agricultural fields to maintain soil structure, fertility, crop protection, and other ecosystem services. High rates of corn stover removal have been shown to negatively affect soil physical properties, but little data are available on the responses of soil microbial communities to stover removal. Soil microbial communities are critical because of their fundamental relationships with C and N cycles, soil fertility, crop protection, and stresses that might be imposed by climate change. As part of a national ARS effort, we assessed the effect of corn stover harvesting on soil microbial communities at four field sites distributed across the U.S. We found some evidence that soil microbial communities were influenced by corn stover removal, but the effects were slow and relatively minor in the no-till systems we examined. Cover cropping appeared to buffer the response of soil microbial to corn stover removal. Documenting changes in soil microbial communities with stover removal under differing soil-climatic and management conditions will guide threshold levels of stover removal and identify potential mitigating practices. Our data suggest that no-till and cover cropping are valuable practices to reduce potential effects of corn stover removal on soil microbial communities.

Technical Abstract: Harvesting of corn stover for cellulosic ethanol production must be balanced with the requirement for returning plant residues to agricultural fields to maintain soil structure, fertility, crop protection, and other ecosystem services. High rates of corn stover removal can be associated with decreased soil organic matter (SOM) quantity and quality and increased highly-erodible soil aggregate fractions. Limited data are available on the impact of stover harvesting on soil microbial communities which are critical because of their fundamental relationships with C and N cycles, soil fertility, crop protection, and stresses that might be imposed by climate change. Using fatty acid and DNA analyses, we evaluated relative changes in soil fungal and bacterial densities and fungal:bacterial (F:B) ratios in response to corn stover removal under no-till, rain fed management. These studies were performed at four different U.S. locations with contrasting soil-climatic conditions and key soil parameters such as SOM and pH. The highest levels of corn stover removal tended to have lower F:B ratios across all the site-years examined; however, the effect was only significant at one of the four locations. At this location, data trends suggest that cover cropping may be an important practice to minimize changes in soil microbial communities. It is probable that no-till practices employed at all locations mitigated rapid changes in soil properties associated with stover removal. We also found that in these no-till systems, the 0 to 5 cm depth interval is most likely to experience changes, and that detectable effects of stover removal on soil microbial community structure will depend on the duration of stover removal, sampling time, soil type, and annual weather patterns. Documenting changes in soil microbial communities with stover removal under differing soil-climatic and management conditions will guide threshold levels of stover removal and identify potential mitigating practices (e.g., no-till, cover cropping). [REAP publication]

Last Modified: 10/25/2014
Footer Content Back to Top of Page