|WEGNER, BRIANNA - South Dakota State University|
|KUMAR, SANDEEP - South Dakota State University|
|SCHUMACHER, THOMAS - South Dakota State University|
|VAHYALA, IBRAHIM - South Dakota State University|
|EYNARD, A - South Dakota State University|
Submitted to: Soil Science Society of America Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/10/2015
Publication Date: 6/3/2015
Citation: Wegner, B.R., Kumar, S., Osborne, S.L., Schumacher, T.E., Vahyala, I.E., Eynard, A. 2015. Soil response to corn residue removal and cover crops in Eastern South Dakota. Soil Science Society of America Journal. DOI:10.2136/sssaj2014.10.0399.
Interpretive Summary: Soil organic matter is a driver of soil health, and crop residues provide many building blocks for soil organic matter. Over the past decades, considerable efforts have been made to utilize crop residue as a possible feedstock for biofuel production. Many questions arise as to the short and long-term impact of removing crop residue on our soil resource. The USDA-Agricultural Research Laboratory located in Brookings, SD has been conducting a long-term experiment to specifically evaluate the impact of removing crop residue on indicators of soil health. Additionally, they have been evaluating cover crops as a tool to replace some of the organic matter lost through the residue removal process. Removal of high levels of crop residue resulted in a decrease in soil organic carbon, as well as decreasing microbial activity compared to when residue remained on the soil surface. The inclusion of cover crop in the short-term (less than 5 years) had mixed results, with no significant trend for improvement in the soil properties we measured, including soil microbial activity and soil structural stability. Trends indicate that surface (0-5 cm) soil organic carbon contents were higher with a cover crop compared to no cover crop although differences were not statistically significant, possibly due to the short duration of cover crops within the experiment (less than 5 years). Additional research to evaluate the long-term impact of incorporating cover crops is needed to evaluate the potential of using this as a management option to offset deleterious effects of removing crop residue for biofuel production. This research contributes to the USDA-ARS-REAP project.
Technical Abstract: Removal of crop residue has been shown to degrade soil organic carbon (SOC), and hence soil quality. The present study was conducted to assess the impacts of corn (Zea mays L.) residue removal and cover crops on various soil quality parameters. The experimental site was located in Brookings County, South Dakota (SD) at the USDA-ARS North Central Agricultural Research Laboratory on a silty clay loam soil. Treatments included: three different residue removal levels each with and without cover crop. The low residue removal (LRR) treatment consisted of harvesting corn grain, leaving all other plant materials on the soil surface. Medium residue removal (MRR) consisted of harvesting grain, then chopping and windrowing the remaining residue and baling. The high residue removal (HRR) consisted of cutting the stalks 0.15 m from the ground and removing. Data from this study show that crop residue removal significantly impacted measured soil properties including SOC, water retention, and water stable aggregates, with minimal differences associated with cover crop. The LRR treatment resulted in higher SOC concentrations thus enhancing the aggregate stability compared to other treatments. The effects of residue removal significantly impacted the microbial activity as measured by hydrolysis of fluorescein diacetate (FDA) in the soil. This study concluded that high residue removal rates led to SOC decomposition and adversely affected soil properties and soil quality, therefore, maintaining crop residue either in the form of the previous crop residue or cover crops is needed to maintain favorable soil properties.