Data/hora: 17/06/2024 19:56:33

Provedor de dados: 	90	
País: 	Brazil	
Título: 	Estimating subsoil resistance to nitrate leaching from easily measurable pedological properties	
Autores: 	Nakagawa,Fábio Keiti; Forti,Gabriel Benjamin Siqueira; Alves,Marcelo Eduardo; Lavorenti,Arquimedes; Miranda,Jarbas Honório de.	
Data: 	2012-11-01	
Ano: 	2012	
Palavras-chave: 	Anion exchange capacity; Remaining phosphorus; Retardation factor.	
Resumo: 	Leaching of nitrate (NO3-) can increase the groundwater concentration of this anion and reduce the agronomical effectiveness of nitrogen fertilizers. The main soil property inversely related to NO3- leaching is the anion exchange capacity (AEC), whose determination is however too time-consuming for being carried out in soil testing laboratories. For this reason, this study evaluated if more easily measurable soil properties could be used to estimate the resistance of subsoils to NO3- leaching. Samples from the subsurface layer (20-40 cm) of 24 representative soils of São Paulo State were characterized for particle-size distribution and for chemical and electrochemical properties. The subsoil content of adsorbed NO3- was calculated from the difference between the NO3- contents extracted with 1 mol L-1 KCl and with water; furthermore, NO3- leaching was studied in miscible displacement experiments. The results of both adsorption and leaching experiments were consistent with the well-known role exerted by AEC on the nitrate behavior in weathered soils. Multiple regression analysis indicated that in subsoils with (i) low values of remaining phosphorus (Prem), (ii) low soil pH values measured in water (pH H2O), and (iii) high pH values measured in 1 moL L-1 KCl (pH KCl), the amounts of surface positive charges tend to be greater. For this reason, NO3- leaching tends to be slower in these subsoils, even under saturated flow condition.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832012000500013	
Editor: 	Sociedade Brasileira de Ciência do Solo	
Relação: 	10.1590/S0100-06832012000500013	
Formato: 	text/html	
Fonte: 	Revista Brasileira de Ciência do Solo  v.36 n.5 2012	
Fonte: 	info:eu-repo/semantics/openAccess