As soils become increasingly sterile and the threat of global food shortages intensifies, Dr Nasmille Larke-Mejía, postdoctoral scientist at the Earlham Institute on Norwich Research Park, explains how her work on agricultural diversity is essential for soil and crop health.

Eastern Daily Press: Nasmille grew up near Cerrejón, Colombia, where she discovered that microorganisms were living off ammonium nitrate fuel oil in open-pit coal minesNasmille grew up near Cerrejón, Colombia, where she discovered that microorganisms were living off ammonium nitrate fuel oil in open-pit coal mines (Image: Nasmille Larke-Mejía)

Each month, those working at the pioneering heart of Norwich Research Park tell us how their work is shaping the world we live in. Read their stories here.

What does your role entail?

I am an environmental microbiologist and postdoctoral researcher working with organisms in different ecosystems to answer questions around soil and crop health. My research uses metagenomics to identify and sequence the DNA of everything present in the soil and computational analysis to reconstruct the genomes of microbes. My work is focused on finding out whether organic agricultural methods lead to more diverse and abundant soil microbiota. As well as my work at the Earlham Institute, I also spend time on the GROW Colombia project.

Why is healthy soil important for global food security?

The amount of sterile soil is increasing year on year. If we are not careful, at some point we're not going to be able to grow anything – 95% of the food we consume is grown in soil, so if it loses its fertility we are less likely to have the yields of food that we have today. And with a growing population, this is going to be a big problem. We need to start thinking about how we can keep these soils diverse, dynamic and efficient.

Soils are living, dynamic systems that are very sensitive to environmental pressures like climate change, rain and erosion – but they're also sensitive to things we add. We often think that if we bury something we can stop thinking about it but, in fact, soils are directly affected by the chemicals we put in the ground – like tea leaves infusing water. I'm investigating organisms that might be able to eliminate toxins and pollutants in the soil before they dissipate.

What is GROW Colombia?

Funded by the Global Challenges Research Fund, GROW Colombia is a project that benefits from knowledge exchange between scientists in the UK and Colombia, aiming to stimulate natural diversity, agricultural diversity and social economics in Colombia through responsible innovation.

I work on the agricultural diversity programme, which aims to improve crop yields via sustainable farming practices. I analyse the impact that conventional agricultural practices have on microbial communities compared to organic ones and how these communities change in specific crops like sugarcane. I am also working with a phytopathogenic fungus that affects coffee plantations.

Why did you decide to pursue a career in science?

I wasn't particularly academic in middle school and had to repeat a year, but my science teacher encouraged me to do my best. I got distinctions in mathematics, physics, chemistry and biology and wanted to study genetic engineering, but my uncle, who is a medical doctor, suggested a career in microbiology.

During my undergraduate degree at the University of Los Andes in Bogotá, I discovered environmental microbiology and became very interested in organisms that can survive in extreme environments and grow on unconventional sources of energy. I grew up in the north of Colombia near Cerrejón, one of the largest open-pit coal mines in the world, where my father worked. For my Masters, I isolated and studied microorganisms present in the mine and discovered that their source of food was ammonium nitrate fuel oil – the explosive that miners use to break the soil apart. That piqued my curiosity and I became really interested in seeing what effect coal mine drilling had on the environment.

Eastern Daily Press: Nasmille loves to go hiking around the UK with her husband in her spare timeNasmille loves to go hiking around the UK with her husband in her spare time (Image: Nasmille Larke-Mejía)

My science career didn’t follow a straight path and I became a school teacher for five years, but I really missed doing research. My students encouraged me to keep going and I found professor J. Colin Murrell, an environmental microbiologist working here in Norwich. He told me about all the incredible things happening at Norwich Research Park. I wanted to be part of it, so I came to UEA for my PhD in 2015.

What’s the best thing about working at Norwich Research Park?

The thing I've enjoyed most is being part of this huge scientific community. People from all over the world work at Norwich Research Park. I've learned about different cultures and have also been able to teach people about my culture, which is amazing.

What do you get up to when you are not working?

During the pandemic, I took up crafts like cross stitch, knitting and sewing. I’ve always loved exploring different environments and have visited the Amazon and the Lost City in Colombia, so travelling the UK has been really nice. I love going to Horsey Beach and when I have an opportunity to go somewhere remote like the Lake District, my husband and I love to go hiking.

Dr Nasmille Larke-Mejía is a postdoctoral scientist at the Earlham Institute. You can follow her on Twitter @wayuu_phd