Microbial Control on Nutrient Cycling and Ecosystem Functioning

Table of contents

It has been reported that the available phosphate sources will be depleted in about 50 years and some authors suggest that we will face a phosphate crisis endangering agricultural production. Thus, it is of critical importance to understand which factors reduce phosphorus loss from soils. Moreover, the production of nitrogen fertiliser is energetically expensive and high levels of nitrate in groundwater are of concern because they can pose a significant health risk and have a negative impact on downstream ecosystems. Hence, this shows that there is a need to better understand which factors influence the N-cycle and reduce N-losses. Until now there are only very few studies that tested whether mycorrhizal fungi can reduce nutrient losses. This is surprising because mycorrhizal fungi are often very abundant in the soil and play a key role in the nutrient cycle of plant communities. Mycorrhizal fungi can forage highly effectively for nutrients in the soil and, by doing so they could prevent leaching of nutrients (e.g. in winter or during periods with heavy rainfall). Moreover, by immobilizing nitrogen in the soil, mycorrhizal fungi could reduce the amount of nitrogen that is lost into the air by the process of biological denitrification.

The following key questions are investigated in this project:

  1. Can mycorrhizal fungi reduce nutrient loss from experimental grassland?
  2. Can arbuscular mycorrhizal fungi reduce nutrient leaching losses at high soil fertility, low temperatures and when rainfall intensity increases?
  3. Is ecosystem sustainability (measured as nutrient retention and reduced nutrient loss after rainfall) enhanced by the presence of diverse communities of arbuscular mycorrhizal fungi?

Participants

Franz Bender (PhD student)
Luise Olbrecht (PhD student)

Prof. Dr. Marcel van der Heijden (responsible professor and supervisor)
Dr. Fritz Oehl (co-supervisor)
Dr. Franz Conen (co-supervisor)
Dr. Franco Widmer (co-supervisor)
Dr. Albrecht Neftel (cooperating partner)
Dr. Hans Stünzi (cooperating partner)