The Ecology of Soil Nitrogen Cycling


  • Teri Balser
  • UW-Madison Dept. of Soil Science
Project Media

In order to truly understand the behavior of nitrogen in the soil, it is important to understand the reasons why it cycles; why and how soil microorganisms use nitrogen. For example, unlike plants soil bacteria can use some forms of nitrogen as an energy source rather than simply for biomass production. Their nitrogen needs and ability to compete for it in the soil are unique. In this talk, we will take an alternative view and explore the hows and whys of the nitrogen cycle from the perspective of soil microorganisms. We will see that nitrogen cycling is a consequence of the growth and activity of microorganisms, and that an understanding of how to ‘think like a microbe’ can help us have a greater understanding of plant-soil nitrogen dynamics.

First, we’ll take a look at the N cycle. We’ve all seen this before, but have we ever really looked at it from the organisms’ perspective? We’ll examine some of the reasons nitrogen cycles in the soils, and where are the important points of control. Finally, we’ll discuss how the ecology of soil organisms might contribute to soil quality, and management issues. Our ability to manage soil and fertilizer inputs for sustainable yield and environmental quality may depend on a greater understanding of soil ecology.