Data/hora: 22/06/2024 01:52:12

Biblioteca(s): 	Embrapa Cerrados.	
Data corrente: 	15/07/1999	
Data da última atualização: 	15/07/1999	
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, soil organic matter, and lime in the Brazilian cerrados.	
Ano de publicação: 	1999	
Fonte/Imprenta: 	In: THOMAS, R.; AYARZA, M.A., ed. Sustainable land management for the oxisols of the Latin American savannas: dynamics of soil organic matter and indicators of soil quality. Cali: CIAT, 1999.	
Páginas: 	p.64-76.	
Idioma: 	Inglês	
Conteúdo: 	In the Cerrados, a large savanna region in Brazil, the effects of different land use on aggregation in Oxisols were studied, using laser diffraction grainsize analysis. The topsoil of plowed systems had significantly fewer macroaggrehates (194-2000 um) and a significantly larger fraction of microaggregates and primary particles (<76 um) than did pastures and native savanna. In plowed systems that were low in soil organic carbon (SOC), lime negatively affected aggregate stability. Lime addition had no effect on topsoil aggregation in land-use systems that were irregularly plowed and generally had a higher SOC content. For all the studied topsoils, pHKCl was positively correlated with the amount of clay dispersed after 3 h of shaking in water. Soil organic carbon did not influence clay dispersion in the range of soils studied. In continuous cropping systems in the Cerrados, a combination of mechanical stress, low SOC, and liming will increase the number of small aggregates and primary particles and hence contribuite to destabilizing 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 - (2455-1) - UPC - PL - -- - CRI4998 -  - CRI4998 - DIS