Institut for Agroøkologi

PhD Project: Mapping Soil Physical Structure of an Agricultural Field for Assessing Potential Leaching Risks

During the last decades detection of pesticides and metabolites in Danish groundwater has increased, forcing several drinking water wells to shut down. There is a need in understanding and describing the soil physical, chemical and structural properties with an effect on pesticide leaching. Which parameters have adverse impacts on the vertical leaching of chemicals down to the groundwater, and how can we predict these parameters from more easy assessable parameters. Proper decisions about groundwater resource protection require large scale decisions. Thus, we will not only consider small-scale laboratory samples, but we will also have to look at field-scale variations and heterogeneities in order to carry out field-scale risk assessments that simulate actual condition. This project is part of the Danish Pesticide Leaching Assessment Programme (PLAP) and two of the agricultural fields (1-3 ha) within this program have been chosen for soil sampling. Laboratory analyses include leaching experiments on undisturbed soil columns, textural and chemical analyses, pesticide sorption and mineralization, and particle-facilitated transport in order to determine properties decisive for pesticide transport/leaching. 

The perspective of the study is to provide authorities with better tools for the regulation of farming practice and protection of the groundwater resources in terms of evaluation of risk and warning against leaching of pesticides. The tool should enable the authorities to formulate more accurate restrictions on land- and agricultural use.