How cleaning out a garden pond led to a sustainable agriculture idea

7 Jun 2022

Image: Prof Marcel Jansen

UCC’s Prof Marcel Jansen explains how he was inspired to investigate the potential of duckweed when cleaning out his pond and how researchers can bridge the ‘valley of death’.

Prof Marcel Jansen studied and worked in the Netherlands, Germany, the UK, Israel, Switzerland and Belgium, before coming to University College Cork (UCC) in 2003. He is a plant scientist, but in recent years has increasingly focused his research on the health of the wider environment – and particularly the aquatic environment.

Jansen’s Plant Stress research group at UCC’s School of Biological, Earth and Environmental Sciences investigates how we can transform wastewater into a new resource to create a more sustainable society. He is the principal investigator for the Brainwaves project, which is looking at how a tiny plant could be used to clean water and create a high-protein crop.

He will be showcasing Brainwaves this weekend at the Cork Carnival of Science, a two-day family STEM festival taking place in Fitzgerald’s Park, supported by Cork City Council and Science Foundation Ireland.

The public are invited to explore, investigate, experiment and discover with live science shows, attractions and interactive stands featuring real scientists working across a range of fields.

‘Our research addresses some of the most urgent challenges in farming and resource management today’

Tell us about the research you’re currently working on.

The ongoing work on the Brainwaves project takes a circular economy approach to sustainable agriculture. That means existing plant nutrients are retained in production systems as long as possible, being reused rather than being discarded.

As part of our approach, we use a common aquatic plant known as duckweed, which thrives on dirty water, taking up nutrients (nitrates and phosphates) as it grows. We’re developing and optimising innovative, high-tech systems to grow duckweed on different types of agricultural waste streams, cleaning the wastewater and resulting in the production of plant biomass.

Sounds good? Yes it does, but it is only half the story. The duckweed biomass is also a very good quality protein crop that can be used as animal feed. In essence, through the uptake of excess nutrients, duckweed can create added value product from waste in the form of a high-protein biomass.

In your opinion, why is your research important?

Our duckweed research at UCC is important as it addresses some of the most urgent challenges in farming and resource management today. Despite copious rainfall in Ireland, overall our rivers contain too much nitrates and phosphates. Water eutrophication is one of our biggest environmental challenges, with harmful knock-on impacts on aquatic ecosystems.

Duckweed systems can be used cheaply to capture some of the nutrients from agri-waste streams, thereby improving water quality. Moreover, by using the high-protein duckweed as a feed, these nutrients are returned to the farm, reducing reliance on chemical fertilisers that are becoming increasingly expensive in recent times.

Additionally, the duckweed as a protein-rich feed source has the potential to alleviate Irish farmers’ reliance on imported soy meal and, further afield, reduce pressure on intensive soybean growing areas, including the Amazon rainforest.

Thus, duckweed research has the potential to bring tangible economic and environmental benefits to farming practices in Ireland and beyond.

What inspired you to become a researcher in this area?

One of the moments that sparked my interest in applied duckweed research happened when I was cleaning out an overgrown pond in my garden in north Cork. I removed half the duckweed floating on the water surface, but then got sidetracked by something else, which at the time was more interesting.

Two days later when I resumed the job of cleaning out the pond, I was baffled to find that the duckweed had again fully covered the pond surface! While I was vaguely aware that duckweed can grow fast, seeing in my own garden a doubling of biomass in two days opened my eyes to the massive potential to use this plant for cleaning waste and generating useful biomass.

What are some of the biggest challenges or misconceptions you face as a researcher in your field?

To me, one of the biggest challenges is the ‘valley of death’ – or the chasm between the wonderful, exciting, weird and wacky ideas of academics, and the more grounded needs of industry and society, where novel ideas must also make legal, practical and commercial sense.

Bridging this valley requires continuous dialogue between academics and those in society and industry that are facing particular problems that need solving. This must be a two-way process where academics reach out to society – but also where society, including communities, policymakers and industry, engage with academics.

This is not an easy process, as to some extent the various groups speak different languages and have different objectives. However, on a positive note, I think we are doing relatively well in Ireland. Our natural tendency to be talkative might have unexpected benefits!

Do you think public engagement with science has changed in recent years?

Public engagement and science communication has dramatically changed over the last two decades. When I was at college, or studying for my PhD qualification, public engagement was not something yet recognised as being particularly relevant.

Consequently, a whole generation of scientists lacks any formal training in this particular aspect of their work. However, on a positive note, most scientists, including myself, are very keen to talk about their work – the challenge is to stop them!

The Covid-19 pandemic has, however, impacted in-person engagement, with social media platforms now becoming key players for us more than ever. Frankly, this sometimes makes me nervous! While as scientists we like to carefully consider, reconsider and re-reconsider our message before sharing it, social media is a fast-moving and at times underregulated environment where truth, semi-truth and fake news are all present.

I am looking forward to the Cork Carnival of Science taking place at Fitzgerald’s Park on Saturday 11 and Sunday 12 June. This family-friendly STEM festival will be the largest outdoor science engagement in Ireland, so we are delighted to share our research with the general public in an easily accessible and fun way over those two days.

10 things you need to know direct to your inbox every weekday. Sign up for the Daily Brief, Silicon Republic’s digest of essential sci-tech news.