Diversity and Activity of Free-Living Nitrogen-Fixing Bacteria and Total Bacteria in Organic and Conventionally Managed Soils

摘要: ABSTRACT Agricultural soils are heterogeneous environments in which conditions affecting microbial growth and diversity fluctuate widely space time. In this study, the molecular ecology of total bacterial free-living nitrogen-fixing communities from Nafferton Factorial Systems Comparison (NFSC) study northeast England were examined. The field experiment was factorial design, with organic versus conventional crop rotation, protection, fertility management factors. Soils sampled on three dates (March, June, September) 2007. Total RNA extracted all soil samples reverse transcribed. Denaturing gradient gel electrophoresis (DGGE) quantitative PCR (qPCR) used to analyze nifH 16S rRNA genes order diazotrophs community, respectively. Crop rotation shown have a significant effect (and that N fixers) (P ≤ 0.001). On dates, activity higher rotation. contrast, qPCR analysis fixers indicated significantly levels conventionally fertilized plots June = 0.0324) protection September 0.0143). To our knowledge, effects farming systems never been studied. An increased understanding impacts practices could allow modifications optimize these organisms.