Data/hora: 09/06/2024 15:30:36

Provedor de dados: 	90	
País: 	Brazil	
Título: 	Sheep Excreta as Source of Nitrous Oxide in Ryegrass Pasture in Southern Brazil	
Autores: 	Tomazi,Michely; Magiero,Emanuelle Cavazini; Assmann,Joice Mari; Bagatini,Tatiane; Dieckow,Jeferson; Carvalho,Paulo Cesar de Faccio; Bayer,Cimélio.	
Data: 	2015-10-01	
Ano: 	2015	
Palavras-chave: 	Climate change; Emission factor; Urine; Dung; Crop-livestock system.	
Resumo: 	ABSTRACT Livestock urine and dung are important components of the N cycle in pastures, but little information on its effect on soil nitrous oxide (N2O) emissions is available. We conducted a short-term (39-day) trial to quantify the direct N2O-N emissions from sheep excreta on an experimental area of ryegrass pasture growing on a Typic Paleudult in southern Brazil. Four rates of urine-N (161, 242, 323, and 403 kg ha-1 N) and one of dung-N (13 kg ha-1 N) were applied, as well as a control plot receiving no excreta. The N2O-N emission factor (EF = % of added N released as N2O-N) for urine and dung was calculated, taking into account the N2O fluxes in the field, over a period of 39 days. The EF value of the urine and dung was used to estimate the emissions of N2O-N over a 90-day period of pasture in the winter under two grazing intensities (2.5 or 5.0 times the herbage intake potential of grazing lambs). The soil N2O-N fluxes ranged from 4 to 353 µg m-2h-1. The highest N2O-N fluxes occurred 16 days after application of urine and dung, when the highest soil nitrate content was also recorded and the water-filled pore space exceeded 60 %. The mean EF for urine was 0.25 % of applied N, much higher than that for dung (0.06 %). We found that N2O-N emissions for the 90-day winter pasture period were 0.54 kg ha-1 for low grazing intensity and 0.62 kg ha-1 for moderate grazing intensity. Comparison of the two forms of excreta show that urine was the main contributor to N2O-N emissions (mean of 36 %), whereas dung was responsible for less than 0.1 % of total soil N2O-N emissions.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832015000501498	
Editor: 	Sociedade Brasileira de Ciência do Solo	
Relação: 	10.1590/01000683rbcs20140497	
Formato: 	text/html	
Fonte: 	Revista Brasileira de Ciência do Solo  v.39 n.5 2015	
Fonte: 	info:eu-repo/semantics/openAccess