Winner of the 2017 Nils Foss Talent Prize 

On 20 November, FOSS had the pleasure of awarding the 2017 Nils Foss Talent Prize to Kristian Holst Laursen, Assistant Professor at the Faculty of Science, Department of Plant and Environmental Sciences at the University of Copenhagen.

Kristian Holst Laursen's work with identifying and treating manganese deficiency in plants has had led to several international ventures, and his passion for solving local agricultural challenges has helped farmers all over the world. His latest research works to safeguard organic food producers by looking at plant authenticity, which can define and eliminate food fraud.  

Read his story below, which takes its beginning in the sandy soil of northern Jutland.  

From cradle to crop 
Kristian Holst Laursen grew up in a small village in the northern part of Jutland. As he tells it, there were two options for youngsters in the local community: get into trouble or go work on one of the local farms.  

Kristian chose the latter and at the age of 10, he started spending his free time at the neighbouring farm. He quickly gained an interest in agriculture and plant production, which manifested in a wish to study agricultural science and become an agronomist. This way, he could assist in solving the challenges that the northern part of Jutland faced in terms of soil fertility, nutrient deficiencies and crop yield losses. This took him to Copenhagen to study at the Royal Veterinary and Agricultural University (which later merged with the University of Copenhagen).  

There, inspired by mentors and fellow students, the area of plant nutrition caught his interest. He was particularly fascinated by the fact that nutritional disorders in plants are causing unique visual deficiency symptoms. By observing the plant and using the theoretical basis, you can therefore pinpoint its nutritional needs, optimize growth conditions and thus provide the basis for an improved crop yield.  

Kristian, who had seen first-hand how farmers could lose entire crops if growth conditions were not optimised, saw the acute relevance of research within this field. He started working together with researchers, Professors Søren Husted and Jan K. Schjoerring, who already were active within this research area.
 
Manganese deficiency – the hidden nutritional disorder 
One of the major problems in Danish plant production at that time was manganese deficiency. Professor Søren Husted’s research group had a strong focus on this and Kristian decided to write his master thesis within this topic. Manganese is a tricky nutrient – it has several essential functions in plants, but its availability in soil is often low. Plants are therefore often manganese deficient but initially they show no symptoms. This may lead to severe yield losses and, in some cases, a complete loss of the crop during winter. Farmers have therefore often taken preventative measures without knowing the need or effect – this was quite common practice in Kristian’s native area.     

The availability of manganese and the potential risk of manganese deficiency during a plant’s growth cannot be predicted by soil analyses. And you can’t treat a detected deficiency with soil fertilisers. The most common approach has thus been to conduct plant analyses, for example using ICP-OES (Inductive Coupled Plasma – Optical Emission Spectroscopy), a time-consuming and destructive method that gives measures of the total amount of manganese in a plant but doesn’t allow for a detailed view of the deficiency. Danish agriculture thus requested new technologies to diagnose manganese deficiency in plants – something they could use directly in the field. 

Together with Professor and mentor, Søren Husted and his research team, Kristian developed a new method for diagnosing manganese deficiency. This method had its basis in fluorescence spectroscopy and focused on the time-dependent change in emission of fluorescent light from the plant’s chlorophyll. The spectre of fluorescent light emerging from the plant as a result of the photosynthesis, was shown to change character in correlation with a change in the manganese levels in the plant. And, because this new analysis was so sensitive and accurate, manganese deficiency could now be determined even in young plants where no physical signs were visible yet. Moreover, the new method was faster, non-destructive and could be used directly in the field. Farmers can now go into the field, measure the manganese levels in a few seconds, apply manganese accordingly and measure an effect within few days. 

For Kristian and three of his colleagues, this new discovery resulted in the birth of a university spin-out company, NutriNostica ApS, which sells fluorescence spectroscopy equipment to farmers, agricultural consultants, fertilizer companies and researchers. The method is now used in 10 countries, most recently in Australia.  

Fighting crime with plant fingerprints 
During his early work on manganese, Kristian gained an interest in analytical chemistry including spectroscopy and mass spectrometry. These tools were also used during his PhD project. In this, he participated in a large interdisciplinary project, investigating differences in the nutritional value and chemical composition of organically and conventionally grown crops. Kristian focused on multi-element analysis and developed a method based on ICP-mass spectrometry that enabled analysis of most elements of the period table in less than a minute. It now became possible to analyse the plant’s ‘fingerprint’, so to say.  

With this method, Kristian observed a strong effect of the geographical location. The soil chemistry was reflected in plants and made it possible to see which country or region the plant came from. This initiated Kristian´s work on food quality and authenticity. When complementing the multi-element analyses with stable isotope ratio analyses, you were able to see large differences between organic and conventional crops. By combining different analytical methods, it was thus possible to reveal not only where but also how a crop had been grown. This area is especially relevant in today’s food markets, because, with the growing demand for high-value products, including organic produce, comes the element of fraud. So, we need new methods for ensuring the authenticity of food products.  

Today, multi-element and stable isotope analysis are used for testing authenticity in a wide range of products including cheese, wine, juice, olive oil and coffee. The method is in continued development to further strengthen the tools we have for defining food authenticity. Kristian and co-workers have recently shown that specific chemical compounds such as nitrate and sulphate are relevant markers for authenticity.  

This enables a much better discrimination between organic and conventional crops. Kristian predicts that compound-specific isotope analysis will gain territory in the food sector the coming years for revealing food crime. In addition, his new methods can be used in basic plant nutrition research. They allow investigations of processes controlling the availability of mineral elements in soils, their uptake and incorporation of these elements in plants with a level of detail that has previously not been possible.  

Teamwork is the key 
Through his work, Kristian has come full circle, from growing up with a natural interest in plants and experiencing the challenges in Danish plant production - to being able to provide the research and direct applications for solving some of these issues, both in his home area and on an international scale. 

And, if you ask him what he thinks is most important within the field of food authenticity, he will probably say teamwork. Collaboration between authorities, universities, food producers and the industry. Only through the harmonization of analytical methods, publicly accessible databases of authentic samples and inter-disciplinary collaborations can we understand, identify and take corrective action when it comes to our crops and the authenticity of our food supply.