How to translate text using browser tools
1 July 2012 Sulfonylurea Herbicides' Fate in Soil: Dissipation, Mobility, and Other Processes
Timothy L. Grey, Patrick E. McCullough
Author Affiliations +
Abstract

Sulfonylurea herbicides used in turfgrass—including chlorsulfuron, flazasulfuron, foramsulfuron, halosulfuron, metsulfuron, rimsulfuron, sulfometuron, sulfosulfuron, and trifloxysulfuron—are all weak acids, with disassociation constants ranging from 3.3 to 5.2. Sulfonylureas are used at low rates ranging from 4 to 280 g ha−1. Although these use rates put their soil concentration in parts per billion, they still have residual activity with variable persistence. They have limited susceptibility to soil leaching with weak adsorption to soil clay minerals. Sulfonylurea herbicides used in turfgrass have variable soil organic matter adsorption, which is soil dependent. The persistence and activity of these sulfonylureas are affected by soil pH. At soil pH of 7.0 and greater, some of these sulfonylurea herbicides tend to persist for longer periods with half-lives extending into years rather than days. In normal use patterns with soil pH of 7.0 and less, dissipation occurs via chemical hydrolysis and microbial degradation with half-lives ranging from days to months. Overall, sulfonylurea herbicide adsorption is negatively correlated to increasing pH (increased persistence) and positively correlated to increased organic matter (decreased activity).

Nomenclature: Chlorsulfuron, flazasulfuron, foramsulfuron, halosulfuron, metsulfuron, rimsulfuron, sulfometuron, sulfosulfuron, trifloxysulfuron.

Weed Science Society of America
Timothy L. Grey and Patrick E. McCullough "Sulfonylurea Herbicides' Fate in Soil: Dissipation, Mobility, and Other Processes," Weed Technology 26(3), 579-581, (1 July 2012). https://doi.org/10.1614/WT-D-11-00168.1
Received: 15 November 2011; Accepted: 1 January 2012; Published: 1 July 2012
KEYWORDS
exponential decay equation
half-life
herbicide dissipation
herbicide persistence
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top