Nitrogen fractions in the microbial biomass in soils of southern Brazil


Autoria(s): Camargo,F. A.O.; Gianello,C.; Vidor,C.
Data(s)

01/03/1999

Resumo

The reaction of nitrogen compounds with ninhydrin can be used as an indicator of cytoplasmic materials released from microbial cells killed by fumigation. Total-N, ninhydrin-reactive-N (NR-N), ammonium-N (A-N), and α-amino-N in the microbial biomass of soils from the State of Rio Grande do Sul, Brazil, were determined, in 1996, in 0.5 mol L-1 K2SO4 extracts of fumigated and non-fumigated soils. Total-N varied from 20.3 to 104.4 mg kg-1 and the ninhydrin-reactive-N corresponded, in average, to 27% of this. The ninhydrin-reactive-N was made up of 67% ammonium-N and 33% aminoacids with the amino group at the α-carbon position. It was concluded that colorimetric analysis of NR-N and A-N may be used as a direct measure of microbial N in soil. This simple and rapid procedure is adequate for routine analyses.

Formato

text/html

Identificador

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06831999000100022

Idioma(s)

en

Publicador

Sociedade Brasileira de Ciência do Solo

Fonte

Revista Brasileira de Ciência do Solo v.23 n.1 1999

Palavras-Chave #Biomass-N #biomass ninhydrin-reactive-N #biomass ammonium-N #biomass α-amino-N
Tipo

journal article