Behind the PhD-degree Yujia Luo

Friday October 7, two colleagues will defend their PhD thesis in Leeuwarden. Yujia Luo is one of them.

As a small kid, she was afraid of mud and was disgusted about the idea of playing with sand. Now, Yujia Luo is the first PhD student to finish a thesis in the Wetsus Soil theme. With her luggage already sent to Ireland, Wetsus certainly was not the most likely place she would end up in.

The science behind the person, and the person behind the science.

A nightmare

“I never imagined I would be studying soil, but here I am!” says Yujia Luo, one of the two PhD-students pioneering in Wetsus soil theme. Though she never was a soilicologist or had the intention of being one, Yujia is the first PhD student to defend her thesis in the Wetsus Soil theme. “My mom told me that I used to cry as soon as I got some dirt om my shoes when I was young, and I would never be interested in it. She was even more surprised that I enjoyed growing crops for an experiment. And getting in the dirt was something she could have never imagined. But I changed.” A lot actually.  

“Being as scientist is what I had always wanted to. But that was because I thought researchers are often working alone. Nicely on their own. Which I would not mind back then. I used to not want to talk to anyone as it evoked such anxiety in me. Luckily, I learned to work together during my Masters in Wageningen.” The whole interconnective basis of Wetsus must have been like a nightmare to her at the time. But that never had been her plan anyway.

A return package from Ireland

Yujia was already determined to do a PhD in Ireland. “I was working in Wageningen as a researcher at the time and got this chance to do my PhD in Ireland. And I would have gone, were it not for an English test I still had to do. By this time, I was convinced I would spend the next three years there – in fact, I had already sent my luggage there!”

Yet there was another chance for Yujia: Wetsus. Although she was not an expert in soils, and Wetsus did not have a theme on soils yet. Her underground water-related research at Wageningen and the connection with her supervisor there, had scouted her as the perfect candidate to pioneer a new dirt theme. And her previous research and laboratory experience would set the basis for this. One return package later, Yujia found herself at the dawn of the soil theme of Wetsus.

Though antonyms at first glance, soil is an essential part of water technology research. Knowing how to treat the ground, makes us understand how to retain water and even absorb CO2. Yujia’s task was to improve the soil using organic amendments – compounds like compost. “We now put chemicals in the ground to make the land fertile, but the question was – is there another way? Can we harness the power of the microbes already present in the soil?”

A black box

It would first require her to study the topic though. “I wanted to learn more on soil myself first. I spent half my PhD studying in Wageningen, Utrecht, and Germany just to get a grasp of what I could find out.” But with that, she was ready to face the science.

“We found out that adding organic amendments, no matter the type of amendment or soil, does little to the soil itself. Although, I did find something unexpected.”

A popular idea is that compost bacteria and nutrients can enrich a land. Using bioinformatics, Yujia challenged this theory. “It is even a widespread idea in literature. And much to my surprise, upon investigating the microbes in the soil once compost was added, the opposite is true. By bringing in the organic amendment, you introduce invaders. Microbes may compete with the native population and plants for resources.” Or at least, that is the theory now.

Though it is hard to make this claim for sure. “Soil is like a black box. It is easy to see what comes in, and what comes out, but to truly understand the process is a big challenge. There are so many microbes, and complex interactions between them and soil variables.”

Planting seeds

And because of it, Yujia stays around another year. “I would love to continue this research. I enjoy learning in any form so much. And I have a feeling I finally know where to head next. The protocols are in place, another PhD is going to pick up where I left. We’ve already seen potential in another project on extracellular polymeric substances to improve soil structure and overall health of the soil.”