Autor:innen:
Franziska Steiner | Soil Science, TUM School of Life Sciences, Technical University of Munich, Freising, Germany | Germany
Shu-Yin Tung | Institute for Agroecology and Organic Farming, Bavarian State Research Center for Agriculture, Freising, Germany | Germany
Tina Köhler | Physics of Soils and Terrestrial Ecosystems, Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland | Switzerland
Nicolas Tyborski | Ecological Microbiology, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, Bayreuth, Germany | Germany
Andreas J. Wild | Agroecology, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, Bayreuth, Germany | Germany
Andrea Carminati | Physics of Soils and Terrestrial Ecosystems, Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland | Switzerland
Tillmann Lüders | Ecological Microbiology, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, Bayreuth, Germany | Germany
Johanna Pausch | Agroecology, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, Bayreuth, Germany | Germany
Sebastian Wolfrum | Institute for Agroecology and Organic Farming, Bavarian State Research Center for Agriculture, Freising, Germany | Germany
Carsten W. Mueller | Department for Geoscience and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark | Denmark
Alix Vidal | Soil Biology Group, Wageningen University, Wageningen, Netherlands | Netherlands
The formation of a stable rhizosheath and the establishment of a distinct soil structure around the root are hypothesised to be beneficial for plants to cope with water scarcity, contribute to improved drought resistance of crop yields and increase soil organic carbon sequestration. However, to date, most results were derived from pot experiments, which are restricted to early plant developmental stages, and therefore impede linking rhizosheath soil properties to crop yield drought resistance or extrapolating results to the field scale.
We conducted a field experiment with 12 maize varieties grown at two sites with contrasting soil textures (sandy vs. loamy soil). Half of the experimental plots received ambient precipitation, while the second half was exposed to water-reduced conditions by the installation of rainout shelter. For each replicate, we sampled the rhizosheath soil and measured its aggregate size distribution as well as soil carbon (C) and nitrogen (N) distribution. At the final harvest, we determined grain dry weight and total above-ground biomass as indicators of maize yield performance.
The preliminary results indicate that the amount of root-adhering soil and the stability of soil aggregates in the rhizosheath were lower under water-reduced conditions. In addition, the contents of N and C were higher in the rhizosheath of plants grown under water limitation. Further, larger amounts of both elements were stored in the microaggregate fractions when the water contents were reduced. The above-ground plant biomass under water scarcity appeared to be largely independent of the assessed rhizosheath soil properties. In contrast, higher grain yields under water-reduced conditions were observed in plants that promoted increased macroaggregation in the sandy soil or had lower contents of N and C in the rhizosheath in the loamy soil.
With the completed dataset, we will deepen the understanding of drought effects on rhizosheath soil properties under field conditions and gather experimental evidence for the potential link between rhizosheath soil properties and crop yield drought resistance.