Sorption and leaching characteristics of pesticides in volcanic ash soils of Jeju Island, Korea

摘要

It is important to evaluate leaching behavior in agricultural soils to prevent the pollution of groundwater by pesticides. We identified the distribution coefficients (Kd) of ten pesticides with different physicochemical properties and compared their leaching characteristics using wick lysimeters from three distinct soil types on Jeju Island. The Kd values varied by pesticide and soil, but were within the range of 1.2 to 4231 L kg?1. Based on the European standard (Kd??10 L kg?1), six pesticides (alachlor, ethoprophos, carbofuran, napropamide, tebuconazole, and etridiazole) were mobile in at least one tested soil, and their soil organic carbon affinity was?≤?5.811. This value differed greatly from the other pesticides (16.533 and higher). The solubility of the six mobile pesticides was?≥?32?mg L?1, which substantially differed from the other pesticides (≤?0.71?mg L?1). Thus, we conclude that our mobility assessment, which is based on Kd values, can be used to predict the leaching of pesticides in the volcanic ash soils of Jeju Island. The use of pesticides should be strictly controlled to reduce the possibility of groundwater contamination.