Data/hora: 17/06/2024 19:56:16

Biblioteca(s): 	Embrapa Cerrados.	
Data corrente: 	30/09/2004	
Data da última atualização: 	30/09/2004	
Autoria: 	MENDES, I. C.; BANDICK, A. K.; DICK, R. P.; BOTTOMLEY, P. J.	
Título: 	Microbial biomass and activities in soil aggegates affected by winter cover crops.	
Ano de publicação: 	1999	
Fonte/Imprenta: 	Soil Science Society of America Journal, Madison, v. 63, p. 873-881, 1999.	
Idioma: 	Inglês	
Conteúdo: 	Witer cover may increase soil organic matter (SOM) and improve soil structure in intensively managed summer vegetable croping systems. Our study examined the influence of three cover crop treatments ( fallow, cereal, and legume within a summer crop rotation of sweet corn and broccoli) on microbiological properties associated with five soil aggregate-size classes (<0.25,0.25 to 0.5 0.5 to 1.0, 1.0 to 2.0, and 2.0 to 5.0 mm) of a willamentte silt loam ( Pachic Ultic Argixerolls). The distribuitions of total organic C ( TOC), total Kjeldahl N (TKN), soil microbial biomass c (SMBC), readily mineralizable Cand N, and two enzyme activities (B-glucosidade and fluorescein diacetade [FDA] hydrolysis) were compared among aggregate-size classes of surface (0-20 cm) soils at seedbed preparation (June 1996) and after harvest of either brocoli (September 1995) or sweet corn (September 1996). Although cover croping did not significantly influence aggregate - size distribuition, TOC, nor TKN on any sampling date, it did significantly (P<0.05) influence SMBC in September 1995, mineralizable C and N and FDA hydrolisys and B- glucosidade activites in june 1996, and levels of mineralizable C and N and B-glucosidade activiy in september 1996. Significant(P<0.01) interactions occurred among the cover crop treatments and aggregate-size classes for SMBC in September 1995, an among mineralizable C and N FDA hydrolisys in june and september 1996. Mineralizable C and N and FDA Hydrolisys differed ( P < 0.01) among aggregatesize classes between june and september 1996: These changes were significantly (P<0.01) sffected by cover crop treatment. these studies identified focal pints for further research on the effects of aggregatesize classes and cover croping on activities and dynamics of their respective microbial communities.	
Palavras-Chave: 	Biomassa microbiana.	
Thesagro: 	Análise do Solo; Cerrado; Física do Solo; Planta de Cobertura; Química do Solo; Solo.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Cerrados (CPAC)	
Exemplares: 	CPAC - (24910-1) - UPC - AP - -- - CRI6355 -  - CRI6355 - DIS