The Effects of Tillage History on Soil Organic Carbon Response to Shifts in Tillage Practices. (5849)
Authors:
G. Yoo* - University of Illinois M.M. Wander - University of Illinois
Abstract:
The influence of no tillage (NT) on soil organic carbon (SOC) sequestration depends on the depth of soil profile considered and initial SOC status (including storage and distribution) when NT practice was applied. This study investigated SOC responses to shifts in tillage practices. Soil samples were collected (0-15, 15-30, 30-60, and 60-100 cm) in spring 2003 from DeKalb, Monmouth, and Orr, IL where NT and conventional moldboard plow (CT) practices had been maintained from 1985 to 1996. In 1996, plots with a history of NT and CT practices were split into CT, NT, and chisel tillage (ChiT) treatments. Carbon concentrations in soils were determined by combustion analysis. Current tillage practices influenced SOC concentrations in the surface soils, whereas, the influence of tillage history was limited to deeper depth. The amounts of SOC stored based on equivalent mass were 9916, 10063, and 9636 g C m -2 in DeKalb, Monmouth, and Orr, respectively.
Current tillage practices did not have a significant influence on SOC storage based on volume and equivalent mass. Irregardless of current tillage practices, soils which had been under NT practice from 1985 to 1996 had greater SOC storage. Our
results imply that when NT practices are applied to soils depleted in SOC by
historic tillage, SOC may be highly stratified but not increased overall compared to soils maintained under CT practice.
Speaker Information: Gayoung Yoo, University of Illinois, N215 Turner Hall 1102 S.
Goodwin Ave., Urbana, IL 61801; Phone: 217 333 4912; E-mail: [email protected]
Session Information: Wednesday, November 3, 2004, 10:00 AM-12:00 PM Presentation Start: 10:00 AM (Poster Board Number: 2544)
Keywords: SOC sequestration; tillage practice; texture; equivalent mass
