In a completely empty office in AU Foulum, Johannes Lund Jensen stood alone with his computer on Friday, 27 March, 2020. What should have been a crowded auditorium had turned into an empty office, a 15” computer screen, and a Skype for Business connection.

"That's how it must be in these Corona times. We must comply with the guidelines,” says Johannes Lund Jensen.

Actually, the PhD defence should have been sent live from Johannes Lund Jensen's home office, but instead he was allowed to do it from an office in Foulum.

"It is a bit difficult to defend your PhD when there are two small children in the house at the same time," explains the newly appointed PhD.

The family watched from home

It was the first PhD defence to be held at the Department of Agroecology after the government sent everyone in the public sector home from work earlier this month. It therefore had a somewhat different form than usual, though the very structure of the defence was quite as usual - a presentation of the dissertation, discussion and finally a voting and reporting.

“I had uploaded my presentation to Skype so that everyone could follow from home in Denmark, Canada and Scotland respectively. It was a strange feeling and at times it was a little difficult to keep the spirits up in a completely empty room with a small screen, but my presentation went really well,” Johannes Lund Jensen says.

In addition to supervisors and opponents, Johannes's family was also on the Skype connection. Technically speaking, Skype for Business worked quite well. Both the presentation and the subsequent discussion proceeded according to plan, and after the hour and a half discussion, the opponents voted. And in front of the audience on Skype, Johannes Lund Jensen was awarded his PhD degree on Friday afternoon.

“It went really well and I think the discussion with the opponents was successful. Of course it was a little strange to be there all alone, usually there is a lot of people to celebrate such an event with, but I knew that my family was eagerly watching home,” Johannes Lund Jensen says.

He was not completely robed of celebration, at home the little family was waiting with lemonade and smiles.

Special requirements online

This is the first time a PhD defence has been conducted virtually at the Department of Agroecology, and it made some special demands on both Johannes and the evaluation committee.

“The virtual PhD defence presents special challenges, both before and during the defence. Before the defence, we spent some time testing the technique. During the defence, a slightly slower rhythm must be observed in the discussion. However, we did not see that the virtual platform put any strain on the discussion between the assessment committee and the student,” says Chris Kjeldsen, senior researcher from the Department of Agroecology, who chaired the evaluation committee. 

Johannes Lund Jensen will not be the only PhD student from the department who will defend his PhD online. On Monday, 6 April, the next PhD student will defend his dissertation online and hopefully with the same great result as Johannes Lund Jensen. 

Read more about Monday's PhD defence here.

Briefly on the PhD thesis

Johannes Lund Jensen's PhD thesis entitled “Identification of soil organic carbon thresholds for sustaining soil functions in arable mineral soils from the humid temperate region” is about identifying lower limit values ??for carbon in soil. 

In the thesis Johannes Lund Jensen looks more closely at whether the relationship between the earth's content of clay and carbon is better related to the functions of the earth than the carbon content itself. In addition, he examined how short-term changes in agricultural operations affect the carbon content and functions of the soil. The results showed that the carbon content of the soil is not in itself a sufficient measure of the state of the soil across different soil types. By contrast, the ratio of clay to carbon is a better indicator of the physical condition of the soil. Short-term changes in soil tillage and the supply of organic matter affected the soil physical properties. The changes in soil physical properties could not only be attributed to changes in carbon content, but also to changed cultivation conditions.

These research results provide an improved basis for setting lower limit values ??for carbon in soil, including the options and limitations associated with the use of critical limit values.

The PhD study was conducted in a collaboration between Aarhus University and Rothamsted Research in the United Kingdom.

Read more about the PhD thesis on Johannes Lund Jensen's pure profile.

Contact

PhD Johannes Lund Jensen, Department of Agroecology at Aarhus University. Tel. +45 2636 0847. Email: jlj@agro.au.dk