Monday, August 3, 2009 - 3:50 PM

SYMP 1-6: Sustainable agroecosystems and soil organisms: Moving towards a process-oriented understanding of management impact

Klaus Birkhofer, Justus Liebig University

Background/Question/Methods Agricultural practices, such as fertilization strategy, severely affect the abundance, activity and diversity of soil organisms. Results of a recent comprehensive sampling in an agricultural long-term experiment suggest complex interactions between fertilization practices and biotic components, leading to pronounced differences in associated ecosystem functions and services between farming systems. As the mechanistic understanding of the development of those differences is still insufficient our follow-up studies focus on the impact of specific management components on interactions in soil animal communities. Farming system specific fertilization strategies affect the resource base for soil organisms, as quality and quantity of fertilizers differ. Such bottom-up effects may cascade up to higher trophic levels and could ultimately change the structure and dynamics of food-web compartments. Additionally, fertilizer mediated differences in plant communities may affect spatial interactions between soil organisms and predators.

Results/Conclusions Information about these “hidden” effects of farming practices on food-web and spatial interactions may contribute to a better understanding of management impacts on soil organisms. Ultimately this knowledge may contribute to the development of improved and sustainable agricultural management practices.