Submitted to: Weed Science Society of America Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 2/7/2011
Publication Date: 2/7/2011
Citation: Oliveira, R., Koskinen, W.C., Alonso, D. 2011. Sorption-desorption of aminocyclopyrachlor in selected Brazilian soils [abstract]. Weed Science Society of America Meeting Abstracts. No. 131. Interpretive Summary:
Technical Abstract: Aminocyclopyrachlor sorption and desorption was investigated in 14 soils from Brazil, representing a range of pH, and organic carbon (OC) and clay contents. Sorption kinetics demonstrated that soil-solution equilibrium was attained in a 24-h period. Freundlich equation adequately described behavior of aminocyclopyrachlor in soil. Freundlich sorption coefficient (Kf) values ranged from 0.06 to 1.64 and 1/n values for sorption were ³ 0.90. Sorption was correlated to OC (Kf,oc ranged from 11 to 64) and clay contents. The lowest sorption was found for soils with very low OC contents (0.50-0.65%) and loamy-sand to sand textures. The 1/n values for desorption were lower than those observed for sorption, suggesting that aminocyclopyrachlor sorption by soil was not reversible; hysteresis coefficients ranged from 0.13 to 0.74. The results suggest that although aminocyclopyrachlor would be very mobile based on its sorption coefficients, its potential mobility may be overestimated due to the hysteretic desorption.