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@INPROCEEDINGS{vonHebel:859494,
      author       = {von Hebel, Christian and Matveeva, Maria and Verweij,
                      Elizabeth and Rascher, Uwe and Rademske, Patrick and Brogi,
                      Cosimo and Kaufmann, Manuela and Mester, Achim and
                      Vereecken, Harry and van der Kruk, Jan},
      title        = {{G}round-based quantitative electromagnetic induction
                      measurements and inversions show that patterns in airborne
                      hyperspectral data are caused by subsoil structures},
      reportid     = {FZJ-2019-00346},
      year         = {2018},
      abstract     = {Non-invasive geophysical fixed-boom multi-coil
                      electromagnetic induction (EMI) instruments return apparent
                      electrical conductivity (ECa) values that depend on
                      subsurface soil properties. Using different
                      transmitter-receiver coil separations and orientations, ECa
                      values of different depths of investigation (DOI) are
                      obtained. After calibration, the quantitative EMI data are
                      inverted to obtain electrical conductivity (σ) changes over
                      depth assuming a layered subsurface model. Airborne
                      hyperspectral measurements are used to estimate plant
                      performance and growth, however, the top- and subsoil
                      structural changes influencing plant performance and growth
                      is often ignored. Here, we have investigated the origin of
                      observed patterns in sun-induced fluorescence data by
                      performing quantitative large-scale EMI measurements and
                      quantitative inversions. The fixed-boom multi-coil EMI ECa
                      data of nine coil configurations indicated spatial patterns
                      due to buried paleo-river channels. After inversion, the
                      obtained layered quasi-3D electrical conductivity model
                      showed a relatively homogeneous ploughing layer and the
                      presence of the paleo-river channels at > 1 m depth.
                      Contrary to often used assumptions, σ of the ploughing
                      layer only showed minor correlation to fluorescence data (r
                      ~ 0.35), while the subsoil returned a significant
                      correlation (r ~ 0.65) indicating a substantial influence of
                      the subsoil on the plant performance, especially during dry
                      periods which is probably due to differences in soil water
                      holding capacity. For the first time, we have related
                      soil-depth specific 3D subsurface information obtained by
                      quantitative multi-coil EMI data inversions with sun-induced
                      fluorescence data and have shown that above surface plant
                      performance is caused by subsoil structural changes.
                      Consequently, the subsurface structures should be
                      incorporated in plant modeling as well as in terrestrial
                      system modeling tools to improve the understanding of
                      soil-vegetation-atmosphere exchange processes.},
      month         = {Apr},
      date          = {2018-04-04},
      organization  = {TR32 Conference: Terrestrial Systems
                       Research: Monitoring, Prediction $\&$
                       High Performance Computing, Bonn
                       (Germany), 4 Apr 2018 - 6 Apr 2018},
      subtyp        = {After Call},
      cin          = {IBG-3 / ZEA-2},
      cid          = {I:(DE-Juel1)IBG-3-20101118 / I:(DE-Juel1)ZEA-2-20090406},
      pnm          = {255 - Terrestrial Systems: From Observation to Prediction
                      (POF3-255)},
      pid          = {G:(DE-HGF)POF3-255},
      typ          = {PUB:(DE-HGF)6},
      url          = {https://juser.fz-juelich.de/record/859494},
}