Sorption and predicted mobility of herbicides in Baltic soils

Abstract

This study was undertaken to determine sorption coefficients of eight herbicides (alachlor, amitrole, atrazine, simazine, dicamba, imazamox, imazethapyr, and pendimethalin) to seven agricultural soils from sites throughout Lithuania. The measured sorption coefficients were used to predict the susceptibility of these herbicides to leach to groundwater. Soil-water partitioning coefficients were measured in batch equilibrium studies using radiolabeled herbicides. In most soils, sorption followed the general trend pendimethalin>alachlor>atrazine∼amitrole∼simazine>imazethapyr>imazamox>dicamba, consistent with the trends in hydrophobicity (log K ow ) except in the case of amitrole. For several herbicides, sorption coefficients and calculated retardation factors were lowest (predicted to be most susceptible to leaching) in a soil of intermediate organic carbon content and sand content. Calculated herbicide retardation factors were high for soils with high organic carbon contents. Estimated leaching times under saturated conditions, assuming no herbicide degradation and no preferential water flow, were more strongly affected by soil textural effects on predicted water flow than by herbicide sorption effects. All herbicides were predicted to be slowest to leach in soils with high clay and low sand contents, and fastest to leach in soils with high sand content and low organic matter content. Herbicide management is important to the continued increase in agricultural production and profitability in the Baltic region, and these results will be useful in identifying critical areas requiring improved management practices to reduce water contamination by pesticides.

Pesticide sorption and leaching potential on three Hawaiian soils

“…K oc (mL g À1 ) t 1/2 (days) References Barriuso et al (1997); Baskaran et al (1996);Ismail and Tet-Vun (2003); James et al (1995) Alachlor 57e457 e 21 8e200 e 13 Patakioutas and Albanis (2002); Sakaliene et al (2007); Sonon and Schwab (1995); Stolpe and Shea (1995); Walker et al (1996); Weed et al (1995); Yen et al (1994) Fig . 1.…”

Effects of pig slurry application on soil physical and chemical properties and glyphosate mobility

“…Glyphosate residues have been found in surface waters (Dores & Freire, 2001;Silva et al, 2003;Queiroz et al, 2011), in groundwater (Sakaliene et al, 2007;Andrade et al, 2011;Britto et al, 2011), and in soil Souza et al, 2006).…”

Pesticidas no perfil de solos em áreas de plantação de cebolas em Ituporanga, SC

“…O alacloro é estimado como tendo baixa lixiviação em solos contendo altos teores de argila e baixos teores de areia; sua mobilidade e persistência são fortemente influenciadas pelo tipo de solo e condições ambientais, tais como temperatura, atividade microbiana, níveis de oxigênio e pH (Johnson & Sims, 1993;Kaur et al, 2002;Sakaliene et al, 2007). O fungicida tebuconazol apresentou a maior frequência em detecção na profundidade de 0 a 20 cm.…”

“…Resíduos de pesticidas são encontrados em corpos de águas superficiais (Molozzi et al, 2006) e subterrâneos (Blanchard & Lerch, 2000;Lapworth et al, 2006;Sakaliene et al, 2007), no solo (Vieira et al, 2009), no ar (Kromer et al, 2004, Yao et al, 2008 e em alimentos (Siqueira & Kruse, 2008;Cantarutti et al, 2009). A dinâmica dos pesticidas, segundo Gustafson (1989) indica sua periculosidade aos sistemas ambientais, em que dois fenômenos são os principais indicadores: a mobilidade e a persistência no meio ambiente, ou seja, a capacidade de sorção à fase sólida e o tempo de meia vida da molécula; ressalta-se que diferentes índices são utilizados para representá-los, sendo o índice GUS (Groundwater Ubiquity Score) um dos mais utilizados.…”