Nitrite isotope characteristics and associated soil N transformations
Dominika Lewicka‐Szczebak, Anne Jansen‐Willems, Christoph Müller, Jens Dyckmans, Reinhard Well
Abstract
Abstract Nitrite (NO 2 − ) is a crucial compound in the N soil cycle. As an intermediate of nearly all N transformations, its isotopic signature may provide precious information on the active pathways and processes. NO 2 − analyses have already been applied in 15 N tracing studies, increasing their interpretation perspectives. Natural abundance NO 2 − isotope studies in soils were so far not applied and this study aims at testing if such analyses are useful in tracing the soil N cycle. We conducted laboratory soil incubations with parallel natural abundance and 15 N treatments, accompanied by isotopic analyses of soil N compounds (NO 3 − , NO 2 − , NH 4 + ). The double 15 N tracing method was used as a reference method for estimations of N transformation processes based on natural abundance nitrite dynamics. We obtained a very good agreement between the results from nitrite isotope model proposed here and the 15 N tracing approach. Natural abundance nitrite isotope studies are a promising tool to our understanding of soil N cycling.