In this post, Seraina Cappelli – postdoctoral fellow at University of Minnesota – presents her work ‘The potential of undersown species identity vs. diversity to manage disease in crops’. She discusses the role of diversity in agriculture, the value of interdisciplinary research platforms and the importance of supportive colleagues for a successful career in science.
About the paper
Our paper is about whether adding extra species to agricultural fields can be used for disease management, whether a higher diversity of extra species improves disease management and why that would be. While biodiversity science has long acknowledged that a high biological diversity is crucial for the long term maintenance of ecosystem functioning and stability of ecosystem services, the reality in modern farming is oftentimes monocultures. The need to incorporate ecological knowledge in modern farming practices is increasingly recognized. Monocultures are notoriously sensitive to massive pest outbreaks, which leads to widespread pesticide use. Pesticides and their breakdown products are found in many places far away from the original application, such as groundwater and nature protection areas, where they harm biodiversity and human health. There is a pressing need to design agroecosystems that are inherently resistant to pathogen and pest outbreaks and less reliant on chemical pest control. Intercropping – growing multiple crops together or in rows – is a known method to naturally reduce pathogen and pest pressure, but intercropping comes with difficulties such as asynchronized maturation of crops and challenging conditions for mechanical harvesting. Using undersown plants, that are planted with the sole purpose of providing specific ecosystem services, as for example pest control, might be more efficient at providing the ecosystem services and they don’t need to be harvested which can help to prevent some of those challenges. Here we wondered which plant species and which of their characteristics make good companions for barley to reduce pathogen pressure in that crop. We used an agricultural biodiversity experiment – the TWINWIN experiment – within a larger research network to test a set of eight species that varied in rooting depth and nitrogen fixation capacities and different combinations of these species for disease regulation potential. We identified two key species, Trifolium repens and T. hybridum, two shallow rooting legumes, as key candidates for net blotch disease management in Nordic barley cultures. A high diversity was not necessary to reduce early season disease in barley, but the undersown species needed to be sufficiently abundant. It would be interesting to see the performance of these two species in real world conditions to test whether our results hold at larger spatial and temporal scales.
About the research
The TWINWIN experiment in Helsinki is embedded in the larger Carbon Action network, that involves different stakeholders such as farmers, policy makers and scientists in Finland. This framework has shown to be very useful to accelerate knowledge exchange between researchers and practitioners and may also help to put our candidate species to a test on real farms. As the name hints, the main goal of the Carbon Action framework is the development of ”carbon farming” methods specific for northern countries. TWINWIN specifically focuses on the role of plant diversity for reaching this goal. However, the network provides research opportunities beyond carbon farming, as our study shows. I happily took the opportunity to study disease in TWINWIN when Anna-Liisa Laine offered me the post-doc position when I was just finishing my PhD. This was right at the beginning of the Covid pandemic, which by now we all know brought its own challenges especially when moving to a new country for a new job. But beyond that, for me as an ecologist one of the main challenges was to incorporate the agronomic focus on crop health and yield into my ecosystem perspective on all species and processes equally.
About the author
I only realized how much fun ecological research is, during my masters thesis. And when I was looking for jobs after finishing my masters degree, I found the PhD project descriptions way more intriguing than most other jobs description. And here I am now, ”post-docing” at the University of Minnesota! Some of the things that I highly value about working in science is the freedom, the wide diversity of tasks and the continuous learning. And most importantly, I do enjoy working with all the smart and inspiring people that I have encountered along my scientific journey, even though being surrounded by so many smart people tends to leave me feeling slightly stupid. I count myself incredibly lucky to have worked with many wonderful people including the co-authors on this paper, who are driven by intrinsic curiosity, a great love for nature and who stay compassionate and supportive, despite the sometimes crushing and cruel dynamics in the academic job market. I have learned only later that the scientific community is not everywhere as warm and welcoming. One of the best advises that I was given by one of those wonderful human beings, I would like to pass on here: The exact research topic is less important than who you do your research with. Make sure to always work with nice people in nice places!
Like the blog post? Read the research here.
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