Occurrence and Distribution of Pesticide Residues in Soil as a Result of Long-Term Application
Summary
Pesticides have been widely used in agriculture for the better part of the past century. While they are known to save farmers time and money, negative effects on human and environmental health have been well described. National and international bodies have identified diffuse pollution by pesticides as a major concern. However, the actual occurrence and distribution of pesticides in the soil is poorly understood, despite soil’s vital role in global biogeochemical cycles. Determination of a wide variety pesticide residues in the soil on a regional scale has historically been difficult and expensive.
In this study, a new methodology is used to extract up to 250 pesticides from the soil. The actual occurrence and distribution of pesticide residues in the soil is determined in two contrasting European agricultural systems: annual rotation of root and cereal crops in the Dutch Atlantic climate and permanent cultivation of oranges in the Spanish Mediterranean climate. This study is also novel in that it incorporates interviews from local experts in linking management practices to pollutant levels.
Indeed some pesticides are still present in the soil, even after forty years since application. With this study, it becomes evident that pesticide residues are probably mobile in the environment via particulate transport and that the concentration of some compounds in the soil exceed acceptable risk levels. However, heterogeneity is still great as compounds behave variably between fields. Assessment of residues on a regional scale may provide more useful assessment of risk to public and environmental health. This study makes further analysis of the risks associated with residues actually present in the soil more feasible.