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Thomas Keller  - - - 
Top co-authors
Achim Walter

35 shared publications

ETH Zurich

Norbert Kirchgessner

14 shared publications

Institute of Agricultural Sciences, Swiss Federal Institute of Technology in Zurich (ETH Zurich), Zurich, Switzerland

Tino Colombi

9 shared publications

Department of Soil and Environment, Swedish University of Agricultural Sciences, Uppsala, 11824, Sweden

Publication Record
Distribution of Articles published per year 
(2002 - 2019)
Total number of journals
published in
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Article 0 Reads 0 Citations The Geophysical Signatures of Soil Structure Alejandro Romero-Ruiz, Niklas Linde, Thomas Keller, Dani Or Published: 03 January 2019
Eos, doi: 10.1029/2019eo112545
DOI See at publisher website ABS Show/hide abstract
Geophysical methods may offer new opportunities for soil structure characterization over varied spatial and temporal scales.
Article 0 Reads 0 Citations A Review of Geophysical Methods for Soil Structure Characterization Alejandro Romero-Ruiz, Niklas Linde, Thomas Keller, Dani Or Published: 03 December 2018
Reviews of Geophysics, doi: 10.1029/2018rg000611
DOI See at publisher website ABS Show/hide abstract
The growing interest in the maintenance of favorable soil structure is largely motivated by its central role in plant growth, soil ecological functioning and impacts on surface water and energy fluxes. Soil structure pertains to the spatial arrangement of voids and solid constituents, their aggregation and mechanical state. As a fragile product of soil biological activity that includes invisible ingredients (mechanical and ecological states), soil structure is difficult to define rigorously, and measurements of relevant metrics often rely on core samples or on episodic point measurements. The presence of soil structure has not yet been explicitly incorporated in climate and Earth systems models, partially due to incomplete methodological means to characterize it at relevant scales and to parameterize it in spatially extensive models. We seek to review the potential of harnessing geophysical methods to fill the scale‐gap in characterization of soil structure directly (via impact of soil pores, transport and mechanical properties on geophysical signals), or indirectly by measurement of surrogate variables (wetness, rates of drainage). We review basic aspects of soil structure and challenges of characterization across spatial and temporal scales and how geophysical methods could be used for the task. Additionally, we propose the use of geophysical models, inversion techniques, and combination of geophysical methods for extracting soil structure information at previously unexplored spatial and temporal scales.
Article 0 Reads 0 Citations Short-term effects of loosening and incorporation of straw slurry into the upper subsoil on soil physical properties and... Gizachew Tarekegn Getahun, Thomas Kätterer, Lars Juhl Munkho... Published: 01 December 2018
Soil and Tillage Research, doi: 10.1016/j.still.2018.06.007
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Subsoils that are compacted, nutrient-poor or low in soil organic matter (SOM) often limit crop growth and yield. Improvement of subsoil conditions by deep loosening is laborious and expensive and its positive effect may not last. This study investigated the effect of deep loosening and injection of slurry made from cereal straw (30 Mg dry mass ha−1) at 25–34 cm depth on soil properties and crop performance in a Swedish field experiment that started in autumn 2015 and monitored soil and crop properties during 2016. Loosening + straw incorporation into subsoil resulted in significantly higher soil organic carbon (SOC) content, potential plant-available water and porosity and lower bulk density (BD) in spring 2016 compared with the control. In autumn 2016, penetrometer resistance (PR) and BD were both significantly lower and SOC and porosity were significantly higher in the loosening + straw treatment compared with the control and loosening only (29–34 cm). Furthermore, BD was significantly lower in the loosening + straw treated subsoil than in the top soil layer of the control (0–10 cm). Observations indicated that more continuous pores were found in the loosening + straw treatment than in other treatments. Roots and soil faunas were found more frequently where straw was incorporated. Grain yield increased by 5.6% due to loosening + straw addition (P = 0.03) and by 4% due to loosening only (P = 0.06). These results indicate that loosening + straw input into upper subsoil had a positive short-term influence on soil physical properties, potential plant-available water and grain yield. Straw addition prolonged the positive effect of loosening.
Article 0 Reads 0 Citations Organic carbon content in arable soil – aeration matters Tino Colombi, Florian Walder, Lucie Büchi, Marlies Sommer, K... Published: 10 October 2018
SOIL Discussions, doi: 10.5194/soil-2018-35
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Arable soils may act as a sink in the global carbon cycle but the prediction of their potential for carbon sequestration remains challenging. The role of soil structure and related physical properties for carbon sequestration is only little explored, especially at the farm level. We hypothesized that improved soil aeration, which is strongly controlled by soil structure, leads to higher soil organic carbon content. Soil gas transport properties, water holding capacity, microbial biomass and soil organic carbon content, were quantified in the topsoil and subsoil in 30 fields of individual farms. The fields were managed either conventionally, organically or according to no-till practice. Tillage significantly increased gas transport capability and water holding capacity of the topsoil. In the same soil layer, organic farming resulted in higher soil organic carbon content and microbial biomass. Both in the topsoil and the subsoil higher gas transport capability and water holding capacity led to increased soil organic carbon content (0.53
Article 0 Reads 1 Citation Feedbacks between soil penetration resistance, root architecture and water uptake limit water accessibility and crop gro... Tino Colombi, Lorena Chagas Torres, Achim Walter, Thomas Kel... Published: 01 June 2018
Science of The Total Environment, doi: 10.1016/j.scitotenv.2018.01.129
DOI See at publisher website
Article 0 Reads 0 Citations Impact of initial bulk density and matric suction on compressive properties of two Oxisols under no-till Renato P. De Lima, Alvaro P. Da Silva, Neyde F.B. Giarola, A... Published: 01 January 2018
Soil and Tillage Research, doi: 10.1016/j.still.2017.09.003
DOI See at publisher website