Data/hora: 09/06/2024 17:49:50

Provedor de dados: 	Revista Brasileira de Ciência do Solo	
País: 	Brazil	
Título: 	Efficiency of nitrogen fertilizer applied at corn sowing in contrasting growing seasons in Paraguay	
Autores: 	Amado,Telmo Jorge Carneiro; Hahn Villalba,Enrique Oswin; Bortolotto,Rafael Pivotto; Santi,Antônio Luis; Benítez León,Enrique Asterio; Menefee,Dorothy; Kunz,Junior.	
Data: 	2013-12-01	
Ano: 	2013	
Palavras-chave: 	Zea mays; Plant nutrition; No-tillage; Soil fertility.	
Resumo: 	In order to select soil management practices that increase the nitrogen-use efficiency (NUE) in agro-ecosystems, the different indices of agronomic fertilizer efficiency must be evaluated under varied weather conditions. This study assessed the NUE indices in no-till corn in southern Paraguay. Nitrogen fertilizer rates from 0 to 180 kg ha-1 were applied in a single application at corn sowing and the crop response investigated in two growing seasons (2010 and 2011). The experimental design was a randomized block with three replications. Based on the data of grain yield, dry matter, and N uptake, the following fertilizer indices were assessed: agronomic N-use efficiency (ANE), apparent N recovery efficiency (NRE), N physiological efficiency (NPE), partial factor productivity (PFP), and partial nutrient balance (PNB). The weather conditions varied largely during the experimental period; the rainfall distribution was favorable for crop growth in the first season and unfavorable in the second. The PFP and ANE indices, as expected, decreased with increasing N fertilizer rates. A general analysis of the N fertilizer indices in the first season showed that the maximum rate (180 kg ha-1) obtained the highest corn yield and also optimized the efficiency of NPE, NRE and ANE. In the second season, under water stress, the most efficient N fertilizer rate (60 kg ha-1) was three times lower than in the first season, indicating a strong influence of weather conditions on NUE. Considering that weather instability is typical for southern Paraguay, anticipated full N fertilization at corn sowing is not recommended due the temporal variability of the optimum N fertilizer rate needed to achieve high ANE.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832013000600020	
Editor: 	Sociedade Brasileira de Ciência do Solo	
Relação: 	10.1590/S0100-06832013000600020	
Formato: 	text/html	
Fonte: 	Revista Brasileira de Ciência do Solo  v.37 n.6 2013	
Fonte: 	info:eu-repo/semantics/openAccess