A Study of carbofuran adsorption and leaching in three soil series of Jaffna Peninsula

Abstract

Carbofuran is a widely used nematicide and insecticide in Jaffna peninsula. Carbofuran is relativelymobile in soil and has the potential to contaminate groundwater. This study examined the adsorptionand leaching potential of carbofuran in three soil series of Jaffna Peninsula. Four replicate soil samplesfrom Chankanai, Inuvil, and Navatkuli series were used for the adsorption study. To study the leaching, a pot experiment was carried out with four replicates in complete randomized design (CRD). Each soil was treated with carbofuran at the departmental rate. Leachate was collected in the 1st, 2nd, and 3rd week and amount of carbofuran was analyzed. The percentages of adsorption were 37.6, 19.2 and 5.6 in Chankanai, Inuvil and, Navatkuli series respectively. Highest percentage of organic matter content (1.71%) may be the reason for the highest adsorption of Chankanai soil. This soil has 17% clay content.

Navatkuli series soil had lowest percentage of organic matter content (0.62%) as well as lower percentage of clay content (8%). Highest carbofuran leaching of 400?g was observed in Navatkuli series. Inuvil and Chankanai soils recorded 244 and 225 ?g respectively. Lowest leaching of Chankanai soil can be explained by highest adsorption of this soil. Likewise, highest leaching of Navatkuli soil can be explained by lowest adsorption. Study indicates that risk of ground water pollution by carbofuran is highest in
Navatkuli series