TY - JOUR A1 - Rudolph-Mohr, Nicole A1 - Gottfried, Sebastian A1 - Lamshöft, Marc A1 - Zühlke, Sebastian A1 - Oswald, Sascha Eric A1 - Spiteller, Michael T1 - Non-invasive imaging techniques to study O-2 micro-patterns around pesticide treated lupine roots JF - Geoderma : an international journal of soil science N2 - The soil root interface is a highly heterogeneous system, e.g. in terms of O-2 and pH distribution. The destructive character of conventional methods disturbs the natural conditions of those biogeochemical gradients. Therefore, experiments aiming to control these influences and study pesticide kinetics under given O-2 and pH conditions suffer from a large uncertainty of the "real" O-2/pH at a certain position. Our approach with two different imaging techniques will examine the soil-root interface as well as the dissipation of the applied pesticide at a high spatial resolution. The obtained outcomes show directly that the pH has an influence on enantioselective dissipation of the acetanilide fungicide metalaxyl. In areas with high pH from an applied racemic mixture, the R-enantiomer dissipates faster than the S-enantiomer. Moreover, we found significantly reduced oxygen values in the bulk soil and vicinity of metalaxyl treated roots compared to control plant roots. The combination of matrix-assisted laser desorption/ionization mass spectrometry (MALDI) and fluorescence imaging indicated the oxygen-dependent behavior of metalaxyl at the root surface. The results presented here underline the great potential of combining different imaging methods to examine the soil-root interfaces as well as the dissipation of organic pollutants in small soil compartments. (C) 2014 Elsevier B.V. All rights reserved. KW - MALDI imaging KW - Fluorescence imaging KW - pH KW - O-2 KW - Rhizosphere KW - Rac-metalaxyl Y1 - 2015 U6 - https://doi.org/10.1016/j.geoderma.2014.10.022 SN - 0016-7061 SN - 1872-6259 VL - 239 SP - 257 EP - 264 PB - Elsevier CY - Amsterdam ER -