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Web URL(s): | http://www.swss.ws/wp-content/uploads/docs/2008 Proceedings-SWSS.pdf#page=87 Last checked: 07/24/2013 Requires: PDF Reader Notes: Item is within a single large file |
Publication Type:
| Report |
Author(s): | Hixson, A. C.;
Weber, J. B.;
Shi, W.;
Yelverton, F. H. |
Author Affiliation: | Crop Science Department, North Carolina State University, Raleigh, NC |
Title: | Turfgrass cover increases soils sorption and degradation of simazine |
Section: | Weed management in turf Other records with the "Weed management in turf" Section
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Meeting Info.: | Jacksonville, Florida: January 27-30, 2008 |
Source: | 2008 Proceedings, Southern Weed Science Society. Vol. 61, 2008, p. 154. |
Publishing Information: | Champaign, Illinois: Southern Weed Science Society |
# of Pages: | 1 |
Keywords: | TIC Keywords: Degradation; Evaluations; Organic matter; Percent living ground cover; Simazine; Soil absorption
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Abstract/Contents: | "Triazine herbicides such as simazine [6-chloro-N,N'-diethyl-1,3,5-triazine-2,4-diamine] are subject to higher mobility in alkaline, sandy soils commonly associated with coastal turfgrass systems. Organic matter is the most important soil constituent influencing pesticide sorption by soils. Bermudagrass is a perennial crop with a constant deposition of organic material creating a soil system that can change drastically with time. These changes in soil physicochemical characteristics could affect the environmental fate of pesticides applied to turfgrass systems. Typically, environmental pesticide regulations are based on research results from row-crop agriculture and may not be applicable to turfgrass systems. Therefore, sorption and degradation characteristics of UL-ring-labeled 14C-simazine were determined in soils from a 10-year-old bermudagrass system and adjacent bareground area. Surface (0-5 cm) and subsurface (5-15 cm) soil from both systems were air-dried and passed through a 4-mm sieve. Using a batch-equilibrium method, sorption isotherms were determined for each soil. Data were fit to the Freundlich equation and Kd (distribution coefficient) values were determined. In addition, degradation of simazine in soils was monitored for three months, using sterile and nonsterile soil microcosms. A factorial design with soil treatments (sterile and non-sterile), soil depths (0-5 and 5-15 cm), and soil system (bermudagrass and bareground) as variables was employed. Distribution coefficients (Kd) indicated sorption was greatest on the surface soil from the bermudagrass soil system (2.47) and lower in all other soils. Sorption decreased as soil depth increased in the turfgrass soil system, but sorption was similar in the bareground system as depth increased. Sorption isotherm slope values (1/n) ranged from 0.78 to 0.83 indicating sorption was nonlinear. Degradation results show that 14CO2 evolution was highest in the subsurface soil of the turfgrass system, indicating higher simazine bioavailability contributes greatly to its increased microbial degradation. Simazine mineralization rate peaked from two to three weeks following soil inoculation indicating quick adaptation of soil microorganisms to simazine in the turfgrass soil. These results indicate leaching potential and bioavailability of simazine is greater in bareground soil and increases with depth in the turfgrass system." |
Language: | English |
References: | 0 |
Note: | This item is an abstract only! |
| ASA/CSSA/SSSA Citation (Crop Science-Like - may be incomplete): Hixson, A. C., J. B. Weber, W. Shi, and F. H. Yelverton. 2008. Turfgrass cover increases soils sorption and degradation of simazine. South. Weed Sci. Soc. Proc. 61:p. 154. |
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| Web URL(s): http://www.swss.ws/wp-content/uploads/docs/2008 Proceedings-SWSS.pdf#page=87 Last checked: 07/24/2013 Requires: PDF Reader Notes: Item is within a single large file |
| MSU catalog number: b2207931 |
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