How do terrestrial plants access high molecular mass organic nitrogen, and why does it matter for soil organic matter stabilization?

Abstract

Although there is increasing awareness of the potential role of organic N compounds (ON) in plant nutrition, its implications for soil organic matter (SOM) stabilization have hardly been discussed yet. The aim of this paper is therefore to gather the newest insights into plant use of high molecular mass organic N, its effect on root growth and anatomy, and finally, to discuss the implications of plant use of organic N for SOM stabilization. I propose that modified root growth due to the uptake of ON provides greater root and root-associated microbe input, leading to enhanced SOM stabilization. Finally, I discuss the role of the proposed framework in different ecosystems, and I encourage future studies combining plant N nutrition and SOM stabilization.