1 Physics of Soils and Terrestrial Ecosystems, Department of Environmental Systems Science, Institute of Terrestrial Ecosystems, ETH Zürich, Universitätsstrasse 16, 8092 Zurich, Switzerland.
2 Chair of Soil Physics, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, Universitätstrasse 30, 95447 Bayreuth, Germany.
3 Soil Science and Soil Protection, Martin Luther University Halle-Wittenberg, Von-Seckendorff-Platz 3, 06120 Halle (Saale), Germany.
4 Department of Soil System Science, Helmholtz Centre for Environmental Research, Theodor-Lieser-Str. 4, 06120 Halle (Saale), Germany.
5 Swiss Light Source, Paul Scherrer Institute, Forschungsstrasse 111, 5232 Villigen, Switzerland.
8 Synchrotron SOLEIL, L'Orme des Merisiers, 91192 Gif-sur-Yvette Cedex, France.
9 Department of Land, Air and Water Resources, College of Agricultural and Environmental Sciences, University of California Davis, One Shields Avenue, Davis, CA 95616, United States.
Although root hairs significantly increased root–soil contact, in maize, their shrinkage during soil drying is initiated at relatively high soil matric potentials (between −10 and −310 kPa).