1 / 1

Objectives

Series Kd r 2 Kd correlations Lanton 2.1 0.98 Prob. Duval 1.3 0.99 Sand 0.03 Brownfield 0.9 0.99 Silt 0.07 Greenville 2.4 0.99 Clay 0.03 Dothan 1.4 0.99 pH 0.67 Cecil 1.4 0.98 CEC 0.23 Tifton 1.3 0.99 OM 0.17 . Introduction

donnel
Download Presentation

Objectives

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. SeriesKd r2Kd correlations Lanton 2.1 0.98 Prob. Duval 1.3 0.99 Sand 0.03 Brownfield 0.9 0.99 Silt 0.07 Greenville 2.4 0.99 Clay 0.03 Dothan 1.4 0.99 pH 0.67 Cecil 1.4 0.98 CEC 0.23 Tifton 1.3 0.99 OM 0.17 • Introduction • Flumioxazin (Valor 51WP) has been labeled for soybean and peanut since 2001. • Flumioxazin has been most commonly used in the peanut growing regions of the South. • No adsorption data currently exist for flumioxazin in the EPA package or in technical data recources • Flumioxazin is non-ionic with a H2O solubility 1.79 mg/L at 25C. • Results • Adsorption • Sorption isotherms were linear. • Flumioxazin is not tightly bound to soil (Kd values 2.4-0.9). • With many Kd’s near 1.0, flumioxazin has near equal affinity for sorbed or solution phase. • OM content was not correlated to flumioxazin sorption. • Adsorption Kinetics • 72% of flumioxazin was bound to soil within 1h; sorption was near instantaneous. • After 72h, sorption was increased to 78%. • Desorption • Desorption rates were similar to adsorption; thus, equlibrium is soil solution will be reached quickly. • Rapid desorption could lead to flumioxazin availability during a rainfall event, thus making it susceptible to leaching. • Objectives • Develop Kd values for flumioxazin on seven soils commonly found in the peanut growing regions of the South. • Describe adsorption kinetics. • Describe desorption of flumioxazin. • Materials and Methods • Batch Equlibrium • 2 g soil. • 10 ml 0.01M CaCl2. • 0, 10, 20, 40, 60 µM flumioxazin. • Shaking time – 24h. • Analysis of adsorption by LCS. Adsorption Kinetics • Greenville sandy clay loam. • Samples removed 1, 6, 12, 24, 48, 72h. • Adsorption quantified by LCS. • Desorption • Initial sorption time – 24h. • Replaced with herbicide free 0.01M CaCl2. • Desorbed for 24, 48, 72, 96h. • Future Research • Determine the relative leaching potential of flumioxazin. • Determine the duration of flumioxazin persistence in soil. • Determine transformation products of flumioxazin by soil microflora. • *The authors thank Valent USA for supplying 14C-flumioxazin.

More Related