Data/hora: 08/06/2024 12:06:24

Provedor de dados: 	90	
País: 	Brazil	
Título: 	Carbon content in Amazonian Oxisols after forest conversion to pasture	
Autores: 	Silva Júnior,Mário Lopes da; Desjardins,Thierry; Sarrazin,Max; Melo,Vânia Silva de; Martins,Paulo Fernando da Silva; Santos,Elaine Rodrigues; Carvalho,Claudio José Reis de.	
Data: 	2009-12-01	
Ano: 	2009	
Palavras-chave: 	Soil carbon stock; Particle-size fractions; Tropical soil; Amazon rain forest.	
Resumo: 	Soil plays an important role in the C cycle, and substitution of tropical forest by cultivated land affects C dynamic and stock. This study was developed in an area of expansion of human settlement in the Eastern Amazon, in Itupiranga, State of Pará, to evaluate the effects of native forest conversion to Brachiaria brizantha pasture on C contents of a dystrophic Oxisol. Soil samples were collected in areas of native forest (NF), of 8 to 10 year old secondary forest (SF), 1 to 2 year old SF (P1-2), 5 to 7 year old SF (P5-7), and of 10 to 12 year old SF (P10-12), and from under pastures, in the layers 0-2, 2-5 and 5-10 cm, to evaluate C levels and stocks and carry out separation of OM based on particle size. After deforestation, soil density increased to a depth of 5 cm, with greater increase in older pastures. Variation in C levels was greatest in the top soil layer; C contents increased with increasing pasture age. In the layers 2-5 and 5-10 cm, C content proved to be stable for the types of plant cover evaluated. Highest C concentrations were found in the silt fraction; however, C contents were highest in the clay fraction, independent of the plant cover. An increase in C associated with the sand fraction in the form of little decomposed organic residues was observed in pastures, confirming greater sensitivity of this fraction to change in soil use.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832009000600009	
Editor: 	Sociedade Brasileira de Ciência do Solo	
Relação: 	10.1590/S0100-06832009000600009	
Formato: 	text/html	
Fonte: 	Revista Brasileira de Ciência do Solo  v.33 n.6 2009	
Fonte: 	info:eu-repo/semantics/openAccess