Data/hora: 21/06/2024 07:34:18

Biblioteca(s): | Embrapa Pantanal.
Data corrente: | 18/10/1995
Data da última atualização: | 07/04/2017
Autoria: | ROSS, D. J.
Título: | Influence of sieve mesh size on estimates of microbial C and N by fumigation-extraction procedures in soils under pasture.
Ano de publicação: | 1992
Fonte/Imprenta: | Soil Biology Biochemistry, v.24, n.4, p.343-350, 1992.
Idioma: | Inglês
Conteúdo: | Measurements were made with five soils from perennial, grazed pastures of the influence of sequential sieving through a 5.6 and 2 mm mesh on estimates of (a) extractable C and N, (b) flushes of C and N, determined by fumigation extraction methods, and (c) mineral-N flush determined by a fumigation-incubation procedure. Wet winter samples, partially dried winter samples and drier summer samples were used. Levels of extractable C and N were highest in smeared and compared, < 2 mm winter samples, largely because of a sieving artefact. In the summer samples, levels were mainly unaffected by sieve mesh size. Flushes of extractable C and N were generally lower in < 2 mm soil than in < 5.6 mm soil; they highest in root residues remaining on the 2 mm mesh. Estimates of mineral-N flush were, however, influenced little by sieve mesh size. Partial drying of the winter samples had no effect on flushes of extractable C, but slightly lowered some extractable-N flush values. In contrast, mineral-N flush values of three of the soils were higher after partial drying. Implications of these for the assessment of kec- and ken-factors, to convert flushes of extractable C and N to microbial C and N, respectively, are discussed. Sieving effects did occur, but they appeared, overall, less marked than other variables influencing these factors.
Palavras-Chave: | Pasture.
Thesagro: | Bioquímica; Pastagem; Solo.
Thesaurus Nal: | biochemistry; soil.
Categoria do assunto: | --
Registro original: | Embrapa Pantanal (CPAP)
Exemplares: | CPAP - (30082-1) - ADD - SP - PP - SP14668 -  - 14668 - DIS