Data/hora: 08/06/2024 16:26:16

Provedor de dados: 	90	
País: 	Brazil	
Título: 	Method to estimate soil macroporosity and microporosity based on sand content and bulk density	
Autores: 	Stolf,Rubismar; Thurler,Álvaro de Mendonça; Bacchi,Osny Oliveira Santos; Reichardt,Klaus.	
Data: 	2011-04-01	
Ano: 	2011	
Palavras-chave: 	Degree of compaction; Modeling; Macropore; Texture; Maximum bulk density; Relative bulk density.	
Resumo: 	Macroporosity is often used in the determination of soil compaction. Reduced macroporosity can lead to poor drainage, low root aeration and soil degradation. The aim of this study was to develop and test different models to estimate macro and microporosity efficiently, using multiple regression. Ten soils were selected within a large range of textures: sand (Sa) 0.07-0.84; silt 0.03-0.24; clay 0.13-0.78 kg kg-1 and subjected to three compaction levels (three bulk densities, BD). Two models with similar accuracy were selected, with a mean error of about 0.02 m³ m-3 (2 %). The model y = a + b.BD + c.Sa, named model 2, was selected for its simplicity to estimate Macro (Ma), Micro (Mi) or total porosity (TP): Ma = 0.693 - 0.465 BD + 0.212 Sa; Mi = 0.337 + 0.120 BD - 0.294 Sa; TP = 1.030 - 0.345 BD 0.082 Sa; porosity values were expressed in m³ m-3; BD in kg dm-3; and Sa in kg kg-1. The model was tested with 76 datum set of several other authors. An error of about 0.04 m³ m-3 (4 %) was observed. Simulations of variations in BD as a function of Sa are presented for Ma = 0 and Ma = 0.10 (10 %). The macroporosity equation was remodeled to obtain other compaction indexes: a) to simulate maximum bulk density (MBD) as a function of Sa (Equation 11), in agreement with literature data; b) to simulate relative bulk density (RBD) as a function of BD and Sa (Equation 13); c) another model to simulate RBD as a function of Ma and Sa (Equation 16), confirming the independence of this variable in relation to Sa for a fixed value of macroporosity and, also, proving the hypothesis of Hakansson &amp;amp; Lipiec that RBD = 0.87 corresponds approximately to 10 % macroporosity (Ma = 0.10 m³ m-3).	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832011000200014	
Editor: 	Sociedade Brasileira de Ciência do Solo	
Relação: 	10.1590/S0100-06832011000200014	
Formato: 	text/html	
Fonte: 	Revista Brasileira de Ciência do Solo  v.35 n.2 2011	
Fonte: 	info:eu-repo/semantics/openAccess