Plant-soil interactions: the cycle of life

Last spring, I gave a TED talk about plant-soil interactions and their importance in the global carbon cycle at a TEDx event organised by Amsterdam University College. You can watch the video below, but for those of you who rather read (actually, I am one of those people, as I never have the patience to watch a video from beginning to end!) you can also read the full text below.

Do you ever think about soils? Do you ever think about soils, other than, when your boots are muddy, or your vegetables dirty? Well, I’m going to talk about soils.

Soils! Without soils, we would not be here. Soils sustain all life on land. And that is because all energy flows through soils, via photosynthesis and respiration.

Have soils always been here?

No!

Have you ever thought about how soils are formed? Where plants came from? And the tiny invisible microbes that live in the soil?

More than 4.5 billion years ago, there was no soil. There wasn’t even life. There were only oceans. But somewhere between 4.5 and 3.5 billion years ago, the first microorganisms appeared in the oceans. There wasn’t even free oxygen at that time! But then, photosynthesis evolved in bacteria, and cyanobacteria started producing oxygen around 2.7 billion years ago. About 1.5 billion years ago, the first fungi appeared, and much later, around 500 million years ago, the first land plants arose. Probably, photosynthesis in these plants was derived from photosynthetic bacteria inside plant cells (the endosymbiosis theory). Those first land plants – like this little liverwort – had no, or very rudimentary roots (remember, there was no soil that they could grow their root in, only rock!), and were likely helped on land by symbiotic fungi. 

And this is where soil started to form. 

Why are Dutch farmers and builders angry and why have I started tweeting in Dutch? The Dutch nitrogen crisis.

You might have seen it in the news: Dutch farmers ravaging cities with their tractors. But this week also builders, contractors, dredgers, and gardeners have protested in The Hague, where our government is based. They are angry, because a lot of their activities and projects have been halted, and farmers in the vicinity of protected natural (Natura 2000) areas might have to move or be bought out.

Why? Because of the Programma Aanpak Stikstof (PAS), a programme designed to reduce nitrogen deposition in Natura 2000 (a European network of protected natural areas) areas while still allowing economic growth and development. Cleverly, this programme allowed nitrogen-emitting activities in the vicinity of these areas if there were planned compensating measures to reduce future emissions, as well as future measures to reduce the degradation of Natura 2000 areas. So, essentially, taking a mortgage on future compensating measures. But on the 29^thof May 2019, the Council of State judged that the PAS could no longer be used to allow nitrogen-emitting activities, because this is challenging European law.

So now, according to some people, The Netherlands is in lock-down. Building projects have been halted, and Dutch livestock numbers need to be reduced. Of course it is understandable that builders and farmers are upset; they are just trying to protect their livelihood.

An extremely dry summer in Manchester

Right at the end of the extremely dry period we had this summer I decided to do a little experiment: I started taking a photo of the patch of grass in my street in Manchester, in the North West of England, every couple of days. I study the effects of drought on ecosystems (see my previous posts about the effects of drought belowground here and here) and I thought it would be nice to show how the grass in my street would bounce back after the rain had started.

Only… it didn’t. The rain did not come as intensely as I expected, and the grass did not bounce back as quickly as I expected. The first (top left) photo was taken on the 12^thof July, the last (bottom right) on the 20^thof August. And still you can see bare soil and brown patches! This patch of grass would look a lot lusher and greener during a normal Manchester summer.

The grass in my street in Manchester this summer. 

But, more importantly, while aboveground plant growth seems mostly recovered, the composition of the community has changed (which you can’t see in these photos), and as I’ve shown in my research, this might continue to affect belowground communities and the processes they perform.

Of course, this little patch of grass in Manchester is not that important for the functioning of our ecosystems. But it is a nice illustration of the impacts of an extremely dry summer on grassland and how long it takes for these fast-growing plants to regain their biomass!

Soil science. A man’s world?

I am a female soil scientist (a soil ecologist, more specifically). And while traditionally the field of soil science has been dominated by men, I’d like to think that women are catching up. Certainly in the labs where I have worked in the last 10 years, women have dominated the postdoc and PhD positions, although this trend yet has to reach the more senior, permanent academic posts. (Unfortunately, there are many reasons why it might not.)

And I couldn’t help but notice that in a recent NERC strategic call for soil science grants (within the larger Soil Security and SARISA programmes), all eight grants that were awarded had male principal investigators. (And that is on top of the fact that all other projects in these two programmes, which were funded about two years ago, are also led by men.)

And because of this traditional male domination of soil science, I thought that maybe, just maybe, and hopefully (in a way), this might just be a true representation of the gender balance of the applications, and of the wider UK soil science community.

So I inquired. And these are the numbers.

Out of 34 applications, 11 were led by female principal investigators – which means that grants led by women made up a reasonably healthy 32% of all grants submitted. And this number is actually representative of the gender balance of the members of the British Society of Soil Science (which assume to be a representation of the UK soil science community as a whole): women make up 30% of its members.

But none of these applications led by women were successful in getting funded. While the female submission rate was 32%, the success rate of female applications was 0%. And while it is well known that grants submitted by women often have lower success rates, this is a pretty low number. I made a graph to visualise it for you, just in case it wasn’t clear yet.

The number of applications and the number of grants awarded in the latest round of Soil Security small grants (between £150k and £250k), split for male and female principal investigators.

Soil boring? My take on the image problem of soil science.

I am passionate about soil, especially about soil biodiversity and how soil organisms and plants interact and control C and N cycling. I have studied soils since I started my undergraduate in 1996, and I have witnessed a complete turnaround when it comes to interest in soil biodiversity and the functions it performs. When I started my PhD, no one was interested in soil organisms and how they regulate crucial ecosystem processes that also happen to be central to sustainable agriculture. Now, everyone is interested – from farmers, to policy makers, to fellow ecologists.

Well, I say everyone, but that is clearly not the case. Soil is still remarkably unsexy. I will illustrate this with a little anecdote.

Last Friday, I met the third year Zoology student who had been assigned to do a final year Science Media Education Project with me. As we walked up the stairs, I asked her what her background was, and she replied and said: “….. and you study soils, right?” in a slightly too upbeat manner. We went to my office, and after finding out that she’d like to interact with primary school children, I suggested organizing a book launch family activity or classroom activity linked to a children’s book about an earthworm that I provided scientific advice for. I explained to her what the book is about (it is about a little worm with low self-esteem, who goes on a journey and meets lots of impressive animals, but eventually finds out that worms are crucial for soil health and plant growth), that the authors are based in Manchester, and that it will come out in February. I saw her face light up as she got increasingly enthusiastic, and I said: “You probably thought, oh no, I have to do a project on soil” to which she replied that she had indeed been a bit worried. When she left, I felt happy that I had been able to excite her about the project, but sad that she had been worried about studying soil.

Sadly, I can’t really blame her.

I, too, often feel deeply bored when I read about soil.

Why is this?

One year later

This is my attempt to revive my severely neglected blog, which I enthusiastically started just before moving to Manchester for my fellowship at The University of Manchester, exactly one year ago.

In that year, a lot has happened, of which, I would say, most was condensed in the second half, which at the same time explains why I haven’t written a blog post since August. I did make one attempt in November, entitled ‘My hole in the ground’, but I never finished it, which says it all, really!

It’s been a good, but unbelievably busy, and, from September, unbelievably stressful year:

We set up a new lab from scratch. We just about got most of the equipment set up and running last month! This has been a challenge, at times, with people (including me) running experiments and needing the lab equipment.

It has also been a challenge, albeit (mostly) an enjoyable one, to get to know how everything works at a new workplace, and to start doing my first teaching. Balancing doing research with students demanding attention and juggling new administrative and marking tasks is something that you have to get used to!

I’ve also submitted three grant proposals, one small one and two big ones (I got the small one, didn’t get one big one, and am still hoping for the second big one).

Then, I am also the chair of Plants, Soils, Ecosystems, a new special interest group of the British Ecological Society. We organized our first (Very successful! Read Sarah Pierce’s report of the meeting here) meeting, which was an extremely fulfilling, but at the same time very stressful thing to do – I am sure it will get easier though!

Finally, I have had a complicated operation on my hand, which was very successful, and has resulted in me being able to do all the things that I used to do before I broke my scaphoid 1.5 years ago: mountain biking, climbing, getting out of the swimming pool, even just leaning on my hand.

But what caused last year to be stressful was the fact that all these things occurred at the same time – in September and October. So, I submitted a big grant proposal, just before I harvested a major experiment while not having a fully set up lab, after which I went straight into my operation, after which I had to teach for the first time, then I organised and chaired our first Plants, Soils, Ecosystems meeting, after which I submitted another big grant proposal. Does this sound crazy? It was.

But, now it’s 2014, I feel refreshed and motivated, and I am determined to revive my blog!

So far, the posts I have been writing varied quite a lot in their topic – from my move to Manchester, to academia in general, to more science-y posts about soils in general, and my own research. I wonder what my readers (if there are any left!) find most interesting and enjoyable to read, but I am tempted to make my posts more science-y, about ecology in general, and plant-soil interactions and soil ecology specifically. If you’re interested the latter two: also keep an eye out for Plants, Soils, Ecosystems’ new journal club, in which we will discuss articles that have recently been published within the broader field of soil ecology and plant-soil interactions. I will post the first paper by the end of next week, and we will aim for bi-weekly/once-a-monthly updates, facilitating (hopefully) lively discussions and interaction between people interested in plant-soil interactions!

Cucumber time

In Dutch, we often call the summer month during which not very much is happening ‘cucumber time’. This is a time during which small news items get blown out of proportion, like cucumber harvests failing, ducklings crossing the road, or princes being born.

For many people in academia however, this relatively student-free period is the time to get on with writing those papers. It is also conference time, because of the same reason – no teaching. In addition, for ecologists, it means the peak of the field season.  So, no time for cucumbers after all.