Data/hora: 29/05/2024 17:14:28

Biblioteca(s): | Embrapa Meio Norte / UEP-Parnaíba.
Data corrente: | 13/02/1996
Data da última atualização: | 13/02/1996
Autoria: | GUPTA, V. V. S. R.; ROPER, M. M.; KIRKEGAARD, J. A.; ANGUS, J. F.
Título: | Changes in microbial biomass and organic matter levels during the first year of modified tillage and stubble management practices on a red earth.
Ano de publicação: | 1994
Fonte/Imprenta: | Australian Journal of Soil Research, v.32, n.6, p.1339-1354, 1994.
Idioma: | Inglês
Conteúdo: | Farming practices involving stubble burning and excessive tillage in Australia have led to losses of organic matter from the soil. Crop residue retention and reduced tillage practices can reverse these trends, but changes in organic matter levels are evident only after a long term. Microbial biomass (MB), the living portion of soil organic matter, responds rapidly to changes in soil and crop management practices. We evaluated changes in microbial biomass and microbial activity in the first year following the modification of stubble management and tillage practices on a red earth near Harden, New South Wales. Following an oat crop harvested late in 1989, seven treatments involving stubble and tillage management were applied in February 1990. Wheat wasplanted in May 1990. Measurements of total organic carbon (C) and total nitrogen (N) in the top 15 cm of soil indicated no significant changes after 1 year, although there was a significant effect on the distribution of C and N. However, significant changes in MB were observed in the first year. Microbial biomass C in the top 5 cm of the soil ranged from 25 to 52 g C m-2 and these levels dropped by 50% or more with each 5 cm depth. Implementation of treatments altered MB, particularly in the top 5 cm where MB-C and MB-N were significantly greater in stubble-retained than in the stubble-burnt treatments, and in the direct drill treatment than in the stubble-incorporated treatment. Microbial biomass in soil increased during the growth of wheat in all...
Palavras-Chave: | Atividade microbiana; Biomassa microbiana; Cultivo; Mineralizacao do nitrogenio; Nitrogen mineralization; Stubble management.
Thesagro: | Matéria Orgânica.
Thesaurus Nal: | microbial activity; microbial biomass; organic matter; tillage.
Categoria do assunto: | --
Registro original: | Embrapa Meio Norte / UEP-Parnaíba (CPAMN-UEPP)
Exemplares: | CPAMN-UEPP - (5032-1) - ADC - SP - -- -  -  - 1996.00059 - DIS