Interview: "Glacial flour could be used as a supplement to agricultural fertilizers"

In this interview, iC3 PhD student Colin Sinclair discusses his research on glacial flour as a soil amendment, his passion for plant growth experiments, and his love for hiking, skiing, and exploring Arctic landscapes.

Can you briefly describe yourself and what you are doing here at iC3?

My name is Colin Sinclair, and I am an iC3-affiliated PhD student. My project Glacier GEOHEALTH focuses on glacial flour. This 'flour' consists of fine-grained sediments such as clay, silt, and sand formed through physical and chemical weathering inside and beneath glaciers. I investigate its physical and chemical properties, including mineral composition and nutrient content, to evaluate its potential as a soil amendment. The aim is to determine whether and how glacial flour can provide essential nutrients to soils and crops, contributing to more sustainable agricultural practices.

Photo credit: Arlynn Sinclair

Why is this research important?

Today, we rely heavily on chemical fertilizers to maximize agricultural yields, but this approach has significant drawbacks. Phosphorus and potassium fertilizers, for example, are mined from limited global sources, creating geopolitical and scarcity risks. Over-fertilization also leads to pollution, as excess nutrients run off into groundwater and surface water. Glacial flour, as a type of rock powder, could serve as a sustainable supplement to these fertilizers. While not a complete replacement, it could help remineralize soils, particularly in regions where nutrients are depleted, and act as a backup in case of fertilizer shortages.

How are you studying glacial flour?

I’m analyzing samples from the Nordic region, including mainland Norway, Svalbard, and Iceland. I study their mineralogy, physical properties, and nutrient content, such as exchangeable phosphorus and nitrogen. I also assess trace metals that could be harmful to soil or plants. Additionally, I conduct plant growth experiments to evaluate how glacial flour affects crop biomass and yield. For example, I’ve grown peas in greenhouses here, at UiT the Arctic University of Norway, and plan to conduct outdoor experiments under Arctic summer conditions in Tromsø.

What inspired you to pursue this research?

The project appealed to me because it combined aspects of my academic background, work experience, and personal interests, such as gardening. I’ve always loved mountains, snow, and ice, and the opportunity to live and work in the Norwegian Arctic was irresistible.

Can you share more about your background?

Before my PhD, I worked in various fields. My master’s research focused on the hydrochemistry of glacial meltwater streams in the Andes, studying the contributions of glacial melt versus groundwater to stream discharge. I’ve also worked in environmental consulting, specializing in groundwater remediation and vapor intrusion.

What challenges have you faced during your PhD?

One challenge was postponing fieldwork in Iceland due to a volcanic eruption. Another was adapting to a new lab setup, as our research group was establishing itself in a new location. On a personal level, becoming a parent during my PhD added complexity, but it also taught me to focus and make the most of my time.

What technologies or methodologies are you the most excited about your field?

Surprisingly, I’ve found that I love the plant growth experiments. Spending time in the greenhouse, designing experiments, and monitoring plant development has been incredibly rewarding.

Do you have future research interests?

Yes, I’d like to explore how to source glacial flour sustainably without causing environmental harm. I’m also interested in studying the formation of glacial lakes due to glacier recession and their impact on downstream ecosystems and nutrient transport.

What has been a particularly memorable moment during your research?

One memorable moment was bringing my wife to Iceland for fieldwork. It was special because Iceland was the first place we ever traveled to together, so returning there for my research felt meaningful.

Photo credit: Arlynn Sinclair

What’s one thing you’re looking forward to in the next year?

Professionally, I’m excited about my next plant growth trial. Personally, I’m looking forward to becoming more fluent in Norwegian, as it enhances my sense of belonging here.

What does an ideal day off look like for you?

It depends on the season. In summer, I enjoy gardening or hiking to a glacier. In winter, I love cross-country skiing and then reading by a snowy window.

If you could travel anywhere in the world, where would you go?

I’d love to explore the high mountains of Central Asia, such as the Himalayas, Tien Shan, or Pamir. These regions fascinate me because of their natural beauty and the interplay between human activity and the environment.

Colin Sinclair is an iC3 affiliated PhD student with the Glacier GEOHEALTH project, working in Tromsø, the capital of Arctic Norway. To find out more about his work with glacial flour, please check this, or contact him by email.