ARS | Publication request: Tillage Systems Influence Glyphosate Degradation in Soils Cropped to Cotton

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 12, 2006
Publication Date: November 12, 2006
Citation: Feng, Y., Balkcom, K.S., Price, A.J., Owsley, M.R. 2006. Tillage Systems Influence Glyphosate Degradation in Soils Cropped to Cotton [abstract]. ASA-CSSA-SSSA Annual Meeting Abstracts. [CD-ROM]

Technical Abstract: The use of herbicide glyphosate has increased significantly in recent years due to the widespread use of Roundup Ready crop varieties and increased adoption of conservation tillage systems. In this study, we evaluated glyphosate mineralization as affected by tillage system, cotton variety, and row spacing. The field experiment was established in 2004 on a Compass sandy loam using a factorial arrangement with four replications. The tillage treatments were conventional and non-inversion deep tillage (conservation) systems. Roundup Ready and conventional cotton varieties were planted at standard (40") and 15" row spacings. Soil samples were collected at 0-10 cm depth in spring of 2005. Laboratory soil incubation was carried out using 14C-glyphosate for 91 days. Preliminary data showed that 32 to 46% of the initial radioactivity was converted to 14CO2. Glyphosate mineralization was significant higher in conservation tillage soils than in conventional till soils regardless of other treatments. Soil microbial community as indicated by PLFA profiles will be assessed.