Climate change impacts on pesticide leaching from arable land – risk assessments and uncertainty analyses

Present climate change scenarios predict increased temperatures and precipitation for important Swedish agricultural regions. The potential risk for leaching of pesticides from arable land is governed by a complex interplay between factors influencing persistence, sorption and transport (e.g. soil temperature, soil moisture, organic matter and precipitation- and drainage patterns). These factors will all be directly influenced by changes in the climate, while indirect influences of climate (changed land use and pesticide usage patterns) will also play an important role. The consequences of these direct and indirect effects will vary between substances, soil types and different regional climates.

The aim of this PhD-project is to explore the potential effects of climate change on pesticide leaching in major Swedish agricultural regions. For this purpose simulations with a process oriented model for pesticide fate and transport in arable land (MACRO) will be used combined with recent climate scenarios from the Rossby Centre (SMHI) and databases on soil types, application times and pesticide leaching for Sweden (CKB and FoMa, SLU). Climate impacts studies include a number of uncertainties. Therefore an important part of the work will focus on examining the relative effects of various sources of uncertainty in the prediction chain. This includes uncertainty in input climate data as well as errors in model structure and parameters. 

The work will be done within the research group: ”Biogeophysics and Water quality” in collaboration with climate researchers at the SMHI Rossby Centre and linked to cooperation with CKB and FoMa (SLU). It will also benefit from current research projects focusing on climate change effects on crop production and nitrate-leaching from arable land (FORMAS, 2008 – 2011, E. Lewan).