TY - JOUR A1 - Weigand, M. A1 - Kemna, A. T1 - Multi-frequency electrical impedance tomography as a non-invasive tool to characterize and monitor crop root systems JO - Biogeosciences J1 - BG VL - 14 IS - 4 SP - 921 EP - 939 Y1 - 2017/02/28 PB - Copernicus Publications SN - 1726-4189 UR - https://bg.copernicus.org/articles/14/921/2017/ L1 - https://bg.copernicus.org/articles/14/921/2017/bg-14-921-2017.pdf DO - 10.5194/bg-14-921-2017 ER -