Soil bacteria and archaea found in long-term corn (Zea mays L.) agroecosystems in Quebec, Canada
Bibliographic record
Abstract
Sheibani, S., Yanni, S. F., Wilhelm, R., Whalen, J. K., Whyte, L. G., Greer, C. W. and Madramootoo, C. A. 2013. Soil bacteria and archaea found in long-term corn ( Zea mays L.) agroecosystems in Quebec, Canada. Can. J. Soil Sci. 93: 45-57. The soil microbial community controls all biological processes in soils and is considered a good indicator of general soil health. Assessment of the microbial community in intensively cropped soils that are under reduced tillage management is especially important because the microbes are the primary decomposers of the high residue input in such systems. We investigated the microbial biomass and diversity of bacteria and archaea in a sandy-loam Dystric Gleysol from a long-term (15 yr) corn (Zea mays L.) agroecosystem in Quebec, Canada, under conventional (CT), reduced tillage (RT), and no tillage (NT) and two residue inputs (high level: +R and low level: -R). Analysis included microbial biomass C and N (MBC, MBN), catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH) and 5-(4, 6-dichlorotriazinyl) amino fluorescein hydrochloride (DTAF) cell counts, 16S rRNA polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and an archaeal clone library. The PCR-DGGE analysis identified Proteobacteria, Actinobacteria and Firmicutes as dominant groups in all tillage and residue management treatments. The archaeal group was diverse, with most individuals identified as belonging to the Crenarchaeota phylum. We also detected soil archaea belonging to the newly proposed phylum Thaumarchaeota, the chemolithoautotrophic ammonia-oxidizing archaeota, in a corn agroecosystem in Quebec, Canada. Microbial biomass increased in the +R treatment according to MBC concentration and direct cell counts. Considering results from the CARD-FISH counts (bacterial and archaeal cell counts without fungal cells) and from MBC results (all microbial biomass including fungi) we concluded the likelihood of greater fungal biomass in the NT plots.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".