Sulphur fertilizer and tillage effects on early season sulphur availability and N:S ratio in canola in western Canada
Bibliographic record
Abstract
Field studies in Manitoba, Saskatchewan and Alberta over 3 yr evaluated immediate and residual effects of source, timing and placement of S fertilizers on sulphate-S supply to canola (Brassica napus L.). The treatments were compared under conventional tillage (CT) and in the establishment years of a reduced (RT) system. Sulphate-S in the soil was measured for two weeks after seeding, using PRS TM -probes. Sulphur concentration and N:S ratio were measured in canola tissue at flowering. Tillage system had little effect on available sulphate, tissue S concentration, N:S ratio or response to S fertilization. Ammonium sulphate (AS) generally increased tissue S concentration and reduced N:S ratio with all placements, and the effects of surface-applied ammonium thiosulphate (ATS) were similar to the effects of AS. Tiger 90, a bentonite-elemental S formulation, generally produced lower S concentrations in canola tissue at flowering than did AS, and levels were similar with elemental S and Tiger 90. Both tissue S concentration and N:S ratio were good indicators of S sufficiency for canola. Sulphate carryover from AS increased tissue S concentration and decreased N:S ratio in the year following application. In contrast, increases in tissue S concentration and decreases in N:S ratio were lower with Tiger 90 than AS. The oxidation of the residual elemental S in Tiger 90 could not be relied upon to increase tissue S concentration above deficiency levels in the year following application where soil sulphate levels were low. Key words: Elemental S, bentonite S, zero tillage, N:S ratio, PRS-probes
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".