Assessing critical plant sulfur concentration and nitrogen to sulfur ratio in spring canola production
Bibliographic record
Abstract
Abstract Aims Plant S concentration (Sc) and nitrogen (N) to S ratio (N:S) in canola are important indicators for diagnosing S deficiency. A field study was conducted on sandy and clay loam soils at two sites in eastern Canada for three growing seasons to determine plant critical Sc and N:S ratios across various growth stages (GSs). Methods For each site year, factorial experiments consisting of combinations of four N levels (0, 80, 160, and 240 kg N ha –1 ) as urea (46–0–0) and four S levels (0, 20, 30, and 40 kg S ha –1 ) as potassium sulfate (0–0–50–18) were classified orthogonally to form 16 combinations. Muriate of potash (0–0–60) was also applied as needed to ensure all plots receiving the equal amount of potassium (K). Results Our study found that S fertilization increased plant Sc at each GS but reduced the whole‐plant N:S ratio, and the effect was stronger during the flowering stage. Both whole‐plant Sc and N:S ratios varied with GS, environment, and soil type and declined with plant aging. Our results showed that whole‐plant S analysis combined with visual signs of plant S deficiency (purple‐edged and cup‐shaped leaves with less green; stunted growth, slow blooming, and fewer flowers) appeared to be the best way to identify S problems in the field, and whole‐plant Sc and N:S ratios could confirm S deficiencies. Conclusion Our findings indicated that if the whole‐plant Sc in the rosette stage is <0.35% and the N:S ratio is >9.6, the plant may be S‐deficient, and timely supplementary S fertilization measures may be beneficial to canola crop yield.
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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 | 0.000 |
| 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".