Data/hora: 16/06/2024 04:55:36

Biblioteca(s): | Embrapa Solos.
Data corrente: | 13/11/2019
Data da última atualização: | 11/11/2021
Autoria: | CHALK, P. M.; INACIO, C. de T.; CHEN, D.
Afiliação: | PHILLIP MICHAEL CHALK, UNIVERSITY OF MELBOURNE; CAIO DE TEVES INACIO, CNPS; DELI CHEN, UNIVERSITY OF MELBOURNE.
Título: | An overview of contemporary advances in the usage of 15N natural abundance (delta N-15) as a tracer of agro-ecosystem N cycle processes that impact the environment.
Ano de publicação: | 2019
Fonte/Imprenta: | Agriculture, Ecosystems & Environment, v. 283, 106570, Nov. 2019.
DOI: | https://doi.org/10.1016/j.agee.2019.106570
Idioma: | Inglês
Conteúdo: | 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 the relative isotopic composition (delta15N signature) of a system component, by innovative selection of experimental conditions that isolate the source or process from confounding factors. Nevertheless, there are examples where significant contemporary advances have occurred in the application of NA as a quantitative tracer, such as in the estimation of the symbiotic dependence of a range of N2 fixing plants. The key is the estimation of isotopic fractionation during N2 fixation and assimilation, and new knowledge has been obtained on factors contributing to variation, and new approaches devised to obtain more accurate estimates of fractionation. A second example is the innovative application of isotopomer measurements of the potent greenhouse gas N2O that enable presumptive identification of the biological and chemical processes resulting in its production under various agricultural scenarios.
Thesagro: | Amônia; Composto Orgânico; Fertilizante; Nitrogênio; Solo.
Thesaurus Nal: | Ammonia; Composts; Fertilizers; Soil.
Categoria do assunto: | P Recursos Naturais, Ciências Ambientais e da Terra
Registro original: | Embrapa Solos (CNPS)
Exemplares: | CNPS - (20296-1) - UPC - AP - DD -  -  - 2019.00206 - DIS