Data/hora: 23/09/2024 01:04:33

Biblioteca(s): 	Embrapa Agrobiologia.	
Data corrente: 	11/03/2021	
Data da última atualização: 	11/03/2021	
Autoria: 	MONGE-MUÑOZ, M.; URQUIAGA, S.; MULLER, C.; HEINRICHS J. C. C.; ZAMAN, M.; CHINCHILLA SOTO, C.; BORZOUEI, A.; DAWAR, K.; RODRÍGUEZ-RODRÍGUEZ, C. E.; PÉREZ-CASTILLO, A. G.	
Afiliação: 	MAYELA MONGE-MUÑOZ, University of Costa Rica; SEGUNDO SACRAMENTO U CABALLERO, CNPAB; CHRISTOPH MÜLLER, Justus Liebig University Giessen; UNIVERSITY OF COSTA RICA; MOHAMMAD ZAMAN, FAO/IAEA; CRISTINA CHINCHILLA-SOTO, UNIVERSITY OF COSTA RICA; AZAM BORZOUEI, Nuclear Agriculture Research School, IRAN; KHADIM DAWAR, University of Agriculture, Peshawar, Pakistan; CARLOS E. RODRÍGUEZ-RODRÍGUEZ, UNIVERSITY OF COSTA RICA; ANA GABRIELA PÉREZ-CASTILLO, UNIVERSITY OF COSTA RICA.	
Título: 	Nitrapyrin effectiveness in reducing nitrous oxide emissions decreases at low doses of urea in an Andosol.	
Ano de publicação: 	2021	
Fonte/Imprenta: 	Pedosphere, v. 31, n. 2, p. 303-3013, 2021.	
ISSN: 	1002-0160	
DOI: 	10.1016/S1002-0160(20)60072-8	
Idioma: 	Inglês	
Conteúdo: 	In the tropics, frequent nitrogen (N) fertilization of grazing areas can potentially increase nitrous oxide (N2O) emissions. The application of nitrification inhibitors has been reported as an effective management practice for potentially reducing N loss from the soil-plant system and improving N use efficiency (NUE). The aim of this study was to determine the effect of the co-application of nitrapyrin (a nitrification inhibitor, NI) and urea in a tropical Andosol on the behavior of N and the emissions of N2O from autotrophic and heterotrophic nitrification. A greenhouse experiment was performed using a soil (pH 5.9, organic matter content 78 g kg?1, and N 5.6 g kg?1) sown with Cynodon nlemfuensis at 60% water-filled pore space to quantify total N2O emissions, N2O derived from fertilizer, soil ammonium (NH4+) and nitrate (NO3?), and NUE. The study included treatments that received deionized water only (control, CK) and two doses of 15N-enriched urea (65 (UR) and 129 mg N kg?1 (UD)) without or with 350 g nitrapyrin for each 100 kg N (UR + NI and UD + NI). No significant differences were observed in soil NH+ content between the UR and UR + NI treatments, probably because of soil mineralization and immobilization (influenced by high soil organic matter content). Nitrapyrin application failed to maintain a stable pool of labeled NO3&#8722; due to the additional NO&#8722; produced by heterotrophic nitrification, which is not effectively inhibited by nitrapyrin. After 56 d, N2O emissions in UR (0.51 ± 0.12 mg N2O-N kg?1) and UR + NI (0.45 ± 0.13 mg N2O-N kg?1) were not significantly different; by contrast, emissions were 36.3% lower in UD + NI than in UD. It was concluded that the soil organic N mineralization and heterotrophic nitrification are the main processes of NH4+ and NO3? production. Additionally, it was found that N2O emissions were partially a consequence of the direct oxidation of the soil's organic N via heterotrophic nitrification coupled to denitrification. Finally, the results suggest that nitrapyrin would likely exert significant mitigation on N2O emissions only if a substantial N surplus exists in soils with high organic matter content.	
Palavras-Chave: 	15N tracer; Autotrophic nitrification; Heterotrophic nitrification; Mineral N; Nitrification inhibitor.	
Thesaurus Nal: 	Tropical grasslands.	
Categoria do assunto: 	P Recursos Naturais, Ciências Ambientais e da Terra	
Registro original: 	Embrapa Agrobiologia (CNPAB)	
Exemplares: 	CNPAB - (41673-1) - UPC - AP - DD -  -  -  - DIS