Calculation of fungal and bacterial inorganic nitrogen immobilization rates in soil

Abstract Microbial inorganic nitrogen (N) immobilization is an important mechanism in the retention of N in soils. However, as a result of the high diversity and complexity of soil microorganisms, there is still no effective approach to measuring the respective immobilization rates of inorganic N by fungi and bacteria, which are the two dominant microbial communities in soils. We propose a mathematical framework, combining the experimentally measurable gross inorganic N immobilization rate and proxies for fungal and bacterial inorganic N immobilization rates, to quantify the respective immobilization rates of inorganic N by fungal and bacterial communities in soil. Our approach will help to unravel the mechanisms of microbial N retention in soils.