Data/hora: 06/06/2024 14:23:18

Biblioteca(s): 	Embrapa Cerrados.	
Data corrente: 	16/02/2000	
Data da última atualização: 	16/02/2000	
Autoria: 	WESTERHOF, R.; BUURMAN, P.; GRIETHUYSEN, C. van; AYARZA, M. A.; VILELA, L.; ZECH, W.	
Título: 	Aggregation studied by laser diffraction in relation to plowing and liming in the Cerrado region in Brazil.	
Ano de publicação: 	1999	
Fonte/Imprenta: 	Geoderma, Amsterdam, v.90, p.277-290, 1999.	
Idioma: 	Inglês	
Conteúdo: 	In the Cerrado savanna region in Brazil, the effects of different land use on Oxisol aggregation were studied, using laser diffraction grain size analyses. The topsoil of plowed systems had significantly lower amount of  macroaggrehates (2000-194 um) and a significantly higher amount of soil in the microaggregate size and and primary particle fraction (<76 um) compared to pastures and the native Cerrado. In plowed systems low in soil organic carbon (SOC), lime had a negative effect on aggregate stability. Lime addition had no effect on topsoil aggregation in land use systems that were not plowed regularly  and generally had SOC content. For all the studied topsoils, pHKCl was positively correlated with the amount of clay dispersed after 3 h of shaking in water. SOC did not influence clay dispersion in the range of soils studied. In continuous cropping systems in the Cerrado region, with a combination of mechanical  stress and low SOC, liming will cause an increase in small aggregates and primary particles and hence contribuite to a destabilization of the soil structure.	
Palavras-Chave: 	Ploughing.	
Thesagro: 	Aradura; Calagem; Cerrado; Estrutura do Solo; Matéria Orgânica.	
Thesaurus Nal: 	liming; organic matter; soil structure.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Cerrados (CPAC)	
Exemplares: 	CPAC - (11945-1) - UPC - SP - -- - CRI5089 -  - CRI5089 - DIS