On September 20th, 2016, the research of two of our PSI organizers- Paula Harkes and Janna Barel– was showcased and up for insightful discussion at our meeting.
Paula started things off by presenting her very interesting work which focused on how the rhizosphere community of an exotic plant species (Senecio inaeguidens) differed from that of a native relative (Jacobea vulgaris). Turns out the new guy (S. inaguidens, or narrow-leaved ragwort, as his friends call him) adjusted well to his new settings, and the rhizosphere community was fairly similar between the two. However, like a fine wine, the rhizosphere community develops with age, and Paula and her team found that plant developmental stage had a strong effect on the bacterial, fungal, and also nematode communities. We discussed reasons for this change across the plant’s life- perhaps differences in primary or secondary metabolites- and the indifference between the native and the exotic species.
Legacies. They’re left by famous leaders, entrepreneurs, and philanthropists, and also, as Janna has found in her research, by plants. Janna and her team tested how winter cover crop mixtures influence the subsequent crops growth through their effect on nutrient cycling and soil pathogens. They found that subsequent crop growth is influenced by the cover crop biomass and nitrogen concentration crops, and mixtures perform better or sometimes worse than their sum of parts. Interestingly, the build-up of soil organic matter differed between cover crops. This, in turn, altered the growth of one cash crop following the cover crop mixture. There were cover-crop enthusiasts in the crowd, and the discussion started about the mechanisms underlying the legacy effects.
As always, we continued the discussion with drinks!
You can find out more about Paula and Janna’s research here:
Paula: https://www.wur.nl/nl/Personen/P-Paula-Harkes-MSc.htm
Janna: https://www.wur.nl/nl/Personen/JM-Janna-Barel-MSc.htm?subpage=projects
Do you have interesting results, a tough question, cool graphs (or all!) that you’d like to share? How about presenting at one of the upcoming PSI meetings?
Plant Soil Interactions Discussion Group 