The 7th International Symposium on Soil Organic Matter (#SOM2019) was held in Adelaide (Australia) from 6 – 11 October 2019. Associate Editor Franciska De Vries kindly agreed to share with us her thoughts and experiences of the conference, below.
My #SOM2019 in Adelaide
Two weeks ago, I travelled to Adelaide to attend the Soil Organic Matter conference in Adelaide, Australia. In December 2019 the chair of the organising committee, Mark Farrell, had invited me as a keynote speaker. This is always very flattering of course, and I had never been to Australia, so I had said yes.
I do have to admit that nearer the time, I started to have some doubts. First, a long-haul flight to Sydney is pretty terrible in terms of carbon emissions. But I also started to feel very nervous about being that long, and far, away from my children (2 and 5 years old). But, the tickets were booked and my name was in the programme. So off I went, after desperately cuddling my children for as long as I could.
And it was worth it!
The meeting was supposed to start (after Sunday evening’s mixer) with a welcome to the land by a representative of the Kaurna people. That welcome was delayed until the end of the meeting, but it was no less impressive. Mickey Kumatpi Marrutya O’Brien told us “If you look after the land, it will look after you”. The Kaurna people place themselves at the bottom of the hierarchy, after land, water, plants, and animals. A stark contrast with our society, and in particular with how we see the soil.

On Monday morning, Dr. Abad Chabbi set the stage with an overview of the role of soil in addressing climate change, food security, and other societal challenges. We then launched into a day of fantastic talks around all aspects of soil organic matter: detailed mechanisms of organic matter accrual on mineral surfaces (Prof. Ingrid Kogel-Knabner), the role of wetlands in carbon storage (Dr. Kerrylee Rogers), and generating models (Dr. Carlos Sierra) and understanding the effects of livestock grazing on soil carbon (Prof. Louis Schipper).

On day two, I was particularly excited about seeing Prof. Josh Schimel talk, and he did not disappoint. His talk focussed on whether we should incorporate information on microbes in global carbon cycling models, or whether they are just too much information (TMI). He showed that just the physical environment of soil organic matter and microbes can make a massive difference for microbial access to soil organic matter, by simply turning a soil core upside down! Take home message for me: microbial control of soil carbon cycling might be particularly important under changing environmental conditions.

Then it was my turn! But obviously I am not going to blow my own trumpet here. Well, I talked about root exudates, and how they can increase soil respiration, and potentially carbon loss, under drought. But I would like to highlight another talk on root exudates that day, by Dr. Marie Zwetsloot, who showed that the phenolic compounds in root exudates might cause priming of soil organic matter decomposition. In the same session, Dr. Mark Bonner gave a very philosophical and intriguing talk about how nitrogen enrichment can shift the balance between white rot and brown rot fungi in boreal forests.
That evening, the conference dinner had kangaroo on the menu. I learned from some Australian colleagues that kangaroos are forming a bit of a pest and that as a result eating their meat is a rather sensible thing to do – and it is also delicious! But unfortunately, most Australians appear not to be very open to eating kangaroo.
On Wednesday, after a very late night, Prof. Francesca Cotrufo gave a fantastic talk (for me this was the highlight of the meeting!) on the relative contribution of mineral associated organic matter (MAOM; the most stable soil organic matter fraction) and particulate organic matter (POM; less stable) across tens of thousands of European soils. She showed that the amount of MAOM saturates across all those soils, but that there is no limit on the amount of POM a soil can store, thus highlighting that we need to focus on increasing POM fractions, particularly in agricultural soils. She was followed by Prof. Johanna Pausch and Prof. Asmeret Asefaw Berhe on rhizosphere processes and soil organic matter transport through landscapes.
On the final day, Prof. Ellis Hoffland (one of my PhD supervisors) gave a very insightful overview about the functionality of soil organic matter; one of the things she highlighted is that in the past we focussed mostly on the importance of soil organic matter for soil fertility, while more recently, the focus has shifted to its potential for mitigating climate change.

Dr. Mark Farrell then closed the meeting – one of the best conferences I’ve ever attended! My compliments to Mark and the rest of the organising committee for hosting an inspiring, diverse (in terms of gender, ethnicity, and career stage), and open meeting on all aspects of soil organic matter. To me it highlighted the excellent and exciting science that is being done on all aspects of soil organic matter, and the potential of using this science for addressing some of the world’s most urgent problems. It also highlighted that really, sometimes, it is worth travelling across the globe; Skype will never replace the actual human interactions that build long-lasting links and collaborations.
Franciska De Vries, Associate Editor of Journal of Ecology, University of Amsterdam, The Netherlands.
More posts from Franciska De Vries: Ecological Inspirations – Predatory Journals – Interview on landscape-scale variation in soil microbial communities – My ESA 2013.