Wendy M. Williamson

Relevance of Interactions amongst Soil Microorganisms to Soil Biological Fertility

In this chapter we discuss trophic interactions within the soil food web, with emphasis on soil microorganisms, and how these interactions influence the release of plant-available nutrients. The theme is that soil fertility is causally linked to interactions between soil biotic components and is exemplified by the interdependence and non-random location of plants and soil organisms. We use a conceptual model of detritus decomposition divided into bacterial and fungal energy channels to illustrate how nonrandom interactions, such as substrate quality and the presence of plant roots, influence soil fertility. Finally, an ecological perspective summarises land management effects on nutrient cycling and identifies key mechanisms that control the fertility of soil in managed systems.