Kabir M., Chotte Jean-Luc, Rahman M., Bally R., Jocteur Monrozier L. (1994). Distribution of soil fractions and location of soil bacteria in a vertisol under cultivation and perennial grass. Plant and Soil, 163 (2), p. 243-255. ISSN 0032-079x.
Titre du document
Distribution of soil fractions and location of soil bacteria in a vertisol under cultivation and perennial grass
Année de publication
1994
Type de document
Article
Auteurs
Kabir M., Chotte Jean-Luc, Rahman M., Bally R., Jocteur Monrozier L.
Source
Plant and Soil, 1994,
163 (2), p. 243-255 ISSN 0032-079x
Effects of soil management on soil characteristics were investigated on the rhizosphere (RPP) and the non-rhizosphere (NRPP) siol of a re-grass vertisol under Digitaria decumbens and in the soil under continuous cultivation (CC). A low energy technique allowed to separate eight size and density fractions, including macro- and micro-aggregates while preserving soil bacteria. Organic C and N, microbial biomass C and the number of total bacteria (AODC) and of Azospirillum brasilense and their distribution were determined in soil fractions isolated from the CC, NRPP and RPP soils. Soil macroaggregates (>2000 micrometers) were similarly predomminant in the NRPP and RPP soils when the dispersible clay size fraction (<2 micrometers) represented more than 25% of the CC soil mass. The main increase of C content in RPP originated from the macroaggregates (>2000 micrometers) and from the root fraction, not from the finer separates. The proportion of organic C as microbial biomass C revealed the low turnover of microbial C in the PP situations, especially in the clay size fraction of the NRPP soil. A common shift of AODC toward the finer separates from planted soils (CC and RPP) revealed the influence of living plants on the distribution of soil bacteria. The relative abundance of A. brasilense showed the presence of the active roots of Digitaria in the macroaggregates and their contact with the dispersible clay size fraction of the rhizosphere soil. (Résumé d'auteur)
Plan de classement
Bactéries [074MICFLO01]
Descripteurs
BIOLOGIE DU SOL ; BACTERIE ; NUMERATION ; VERTISOL ; BIOMASSE ; HERBACEE ; DENSITE DE POPULATION ; AGREGAT
