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Per Schjønning

Senior Researcher

Per Schjønning, born 22.10.1953

Scientific degrees
M.Sc. in agriculture from Royal Veterinary and Agricultural University (KVL)

Scientific positions
2007- present: Senior scientist at Aarhus University, Department of Agroecology
1997-2006: Senior scientist at the Danish Institute of Agricultural Sciences
1989-1997: Senior Scientist at the Danish Institute of Plant and Soil Science
1980-1989: Scientist at the Danish Institute of Plant and Soil Science

Research areas and activities
Per Schjønning (PSC) has covered a wide range of research topics. The focus area generally relates to soil quality of managed ecosystems, especially soil physical properties and functions as related to soil productivity as well as environmental impacts. More specifically: Soil structural stability (clay dispersibility, aggregate strength, bulk soil mechanical strength); Gas diffusion and air permeability; Pore characteristics in relation to gas- as well as water flow in soil; Self-organization in the soil-microbe system; Soil abiotic conditions affecting microbial and chemical processes in soil; Management effects on soil structure (e.g. soil tillage, crop rotation, fertilization); Soil tillage; Soil compaction (processes and modelling). PSC has served as Primary Investigator for numerous national and international research projects focusing soil properties in managed soils. PSC has a broad international network. He chaired an early EU project (1985-1989) on soil mechanical properties and has participated in EU concerted actions on soil compaction. He participated in the work with the EU Soil Thematic Strategy. Member of the International Soil Tillage Research Organization (ISTRO) and served as the vice-chairman of the executive committee organizing the 13th international conference of ISTRO in 1994 in Aalborg, Denmark. He is Danish member of the Council of the European Society for Soil Conservation (ESSC). Peer reviewer for a range of research journals, in particular Soil & Tillage Research, Soil Use and Management, and Geoderma.

Student supervision and outreach
Supervised a range of MSc and PhD students. Edited an international book on soil quality in relation to soil management. Numerous presentations at international conferences and a multitude of lectures for extension officers national and abroad. Principal author of a recent report on threats to soil quality in Danish agriculture as reviewed in the context of the upcoming EU Soil Framework Directive. Emphasizes and implements the use of research chains in his research, including expertise ranging from empirical to mechanistic and from qualitative to quantitative. One example is the creation of the decision support system Terranimo©, available at www.soilcompaction.eu, tab ‘Terranimo’.

Recent and current research activities and project commitments
PSC has an extensive experience in multidisciplinary research projects including a range of national and international partners. Examples of recent projects are (PSC role in parantheses):
Preventing and Remediating degradation of soils in Europe through Land Care (RECARE; 2013-2018; Case-study leader). The main aim of RECARE is to develop effective prevention, remediation and restoration measures using an innovative trans-disciplinary approach, actively integrating and advancing knowledge of stakeholders and scientists in 17 Case Studies, covering a range of soil threats in different bio-physical and socio-economic environments across Europe.
Stress-strain behavior of agricultural soils: towards new approaches (StressSoil; 2012-2014)(The Danish Council for Technology and Production Sciences, project leader). A project aiming at new approaches for describing soil structure and soil mechanical strength in relation to mechanical stresses exerted during traffic in agricultural fields. International cooperation with groups in Switzerland and France.
Preparing for the EU Soil Framework Directive by optimal use of Information and Communication Technology across Europe (PredICTor; 2011-1013)(EU-project, ICT-AGRI, NaturErhvervstyrelsen; project leader). An international group with participation from Switzerland, Finland, Germany, The Netherlands and Denmark put up a decision support tool for minimizing soil compaction in field traffic. An additional task was to produce Wheel Load Carrying Capacity maps for European soils.
Persistent effects of subsoil compaction on soil ecological services and functions (POSEIDON; 2009-2013)(The Nordic Joint Committee for Agricultural and Food Research, project leader). An inter-Nordic project focusing the environmental aspects of soil compaction (www.poseidon-nordic.dk). Exciting new methodologies (CT) have revealed persistent effects of subsoil compaction. This project includes four national groups (Denmark, Norway, Finland, Sweden).
Quantifying diffusion constraints on aerobic microbial activity in structurally intact soil (DIFCON; 2005-2007)(The Danish Council for Technology and Production Sciences, project leader). This project investigated the drivers for solute diffusivity and in that context a new method for the purpose was developed.

Publications
Senior or co-author of >200 publications of which 104 are in international refereed journals, 21 are national peer-reviewed papers, 10 are book chapters, >50 conference papers. Web of Science, November 2013: cited by others 1968 times; H-index=29; 38 papers published 2010-2013. Editor of internationally published book (CAB International, 2004).

Selected, recent papers
Arthur, E., Schjønning, P., Moldrup, P., Razzaghi, F., Tuller, M., de Jonge, L.W. Soil structure and microbial activity dynamics in 20-month field-incubated organic-amended soils. European Journal of Soil Science (in press).

Abdollahi, L., Schjønning, P., Elmholt, S., Munkholm, L.J. 2014. The effects of organic matter application and intensive tillage and traffic on soil structure formation and stability. Soil & Tillage Research 136, 28-37.

Schjønning, P., Lamandé, M., Berisso, F.E., Simojoki, A., Alakukku, L., Andreasen, R.R. 2013. Gas diffusion, non-Darcy air permeability, and computed tomography images of a clay subsoil affected by compaction. Soil Science Society of America Journal 77, 1977-1990.

Schjønning, P., Thomsen, I.K. 2013. Shallow tillage effects on soil properties for temperate-region hard-setting soils. Soil & Tillage Research 132, 12-20.

Schjønning, P., Eden, M., Moldrup, P., de Jonge, L.W. 2013. Two-chamber, two-gas and one-chamber, one-gas methods for measuring the soil-gas diffusion coefficient: Validation and inter-calibration. Soil Science Society of America Journal 77, 729-740.

Schjønning, P., de Jonge, L.W., Munkholm, L.J., Moldrup, P., Christensen, B.T., Olesen, J.E. 2012. Clay dispersibility and soil friability – Testing the soil clay-to-carbon saturation concept. Vadose Zone Journal 11, doi:10.2136/vzj2011.0067.

Schjønning, P., Lamandé, M., Keller, T., Pedersen, J., Stettler, M. 2012. Rules of thumb for minimizing subsoil compaction. Soil Use and Management 28, 378-393.

Berisso, F.E., Schjønning, P., Keller, T., Lamandé, M., Simojoki, A., Iversen, B.V., Alakukku, L., Forkman, J. 2013. Gas transport and subsoil pore characteristics: Anisotropy and long-term effects of compaction. Geoderma 195-196, 184-191.

Laegdsmand, M., Moldrup, P., Schjønning, P. 2012. Solute diffusivity in undisturbed soil: Effects of soil water content and matric potential. Soil Science Society of America Journal 76, 51-60.

Lamandé, M., Schjønning, P. 2011. Transmission of vertical stress in a real soil profile. Part II: Effect of tyre size, inflation pressure and wheel load. Soil & Tillage Research 114, 71-77.