Shoot Growth, Phosphorus–Nitrogen Relationships, and Yield of Canola in Response to Mineral Phosphorus Fertilization
Bibliographic record
Abstract
Crop responses to increasing P fertilization are often variable and poorly related to soil P test. Our objectives were to determine the influence of P fertilizer on the growth and seed yield of canola ( Brassica napus L.) and to develop a first approximation of its critical phosphorus concentration (P c ) in shoot biomass. An experiment with four rates of P fertilizer (0, 20, 40, and 80 kg P ha −1 ) was conducted on soils with a low available P content at 5 site‐years [Normandin (QC; 2010, 2011, 2012) and Brandon (MB; 2010, 2012)] in Canada. Dry matter (DM) yield, and N and P concentrations were measured weekly on 5 d from early bolting to late flowering, and seed yield was measured at harvest. Seed yield was significantly increased by P fertilization at only 1 of the 5 site‐years, even though a positive response was expected at all site‐years. Phosphorus fertilization did not affect shoot growth and P uptake at any of the 5 site‐years. However, the estimated shoot biomass on the first sampling day was reduced with no P application at 3 of the 5 site‐years. A reduction in early crop growth of more than 30%, however, was required to affect seed yield. The whole‐plant canola P c was expressed as function of N concentration (P c = 1.74 + 0.024N, R 2 = 0.24, P = 0.05) but this first approximation requires further validation.
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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".