An overview of contemporary advances in the usage of 15N natural abundance (δ15N) as a tracer of agro-ecosystem N cycle processes that impact the environment
PM Chalk, CT Inácio, D Chen
Agriculture Ecosystems & Environment | Elsevier BV | Published : 2019
© 2019 Elsevier B.V. During the past 20 years there have been major advances in the application of 15N natural abundance (NA) measurements to trace the pathways and magnitudes of N fluxes in the soil-plant-atmosphere continuum. However, estimates are often not quantitative due to the unknown extent of isotopic fractionation during a particular N transformation under study, when other processes compete simultaneously for substrate. Examples are the estimation of N fertilizer use efficiency or the transfer of biologically-fixed N2 to non-fixing companion species in intercrops or crop sequences. In some cases it has been possible to identify a particular process or source leading to a change in..View full abstract
We thank Dr. Fabiano Balieiro for drawing Fig. 1. We also thank the University of Melbourne for supporting this work by providing funds for our participation in the 7th International Nitrogen Initiative 2016 conference in Melbourne, Australia, and the 21st World Congress of Soil Science 2018 in Rio de Janeiro, Brazil, which provided us with opportunities to review progress and to plan the completion of the review.