How did the research turn out? What were the findings? Researchers themselves report briefly on the research they have undertaken with funding support from the Formas Research Council.
Editor: Margaretha Nordahl
Diversity in the food webs of the soil
Katarina Hedlund (project leader)
Summary of results with list of publications from Lund University
Email: katarina.hedlund@zooekol.lu.se
The species rich communities of organisms in the soil are part of a food web of which we have only little knowledge today. Many researchers have thought for a long time that many processes in the soil may retain their functions despite a low diversity among the soil organisms. One reason appears to be that there is a large proportion of general functions that are retained despite the disappearance of species. This assumption is due rather to a lack of methods which can detect and identify specific functions in the food webs of the soil.
In this project, a study was therefore made to find which mechanisms control the structure of the food web, and methods have been developed that show how the fluxes of e.g. carbon can be studied in the food webs of the soil. The results show how the flux of carbon and other nutrients occurs through more specific pathways among organisms than had been thought. The methods show that there are many indirect pathways among the soil organisms which are important for the stability of the food webs and ecosystems in the soil, which helps us understand why we consider the soil ecosystems to be robust to disturbances.
Emissions of nitrous oxide from organic farming controlled by the nitrogen effectiveness of the system
Leif Klemendtsson (project leader)
Summary of results with list of publications from Department of Botany, Chemical Ecology, Göteborg University
Agriculture is responsible for 65-80% of the increase in atmospheric nitrous oxide – a long lived and powerful greenhouse gas. It is produced by bacteria in soils where nitrogen is available, oxygen levels are low and there is organic matter to decompose at the right temperature. In organic agriculture, the crops are dependent on nitrogen that is liberated from organic matter when the crop does not take up nitrogen, which has been considered to result in higher emissions than conventional agriculture.
The supply of nitrogen in organic farming through the use of green manure crops has been found to result in large losses of nitrogen in the form of leaching and poor utilisation of nitrogen. In this project, a comparison has been made of the way nitrous oxide emission is affected by organic and integrated farming methods, where the latter uses mineral fertilisers. The study has provided knowledge of how the soil can be farmed so as to produce low emissions.
Responsible for this page: Birgitta Bruzelius