Effectiveness of seedrow placement of granular copper products for wheat
Bibliographic record
Abstract
The practice of placing granular Cu fertilizers with the seed of cereals and oilseeds has been expanding in western Canada mainly due to the high cost of applying the minimum suggested broadcast and incorporation rate of 3.5 kg Cu ha-1. The hypothesis made is that annual applications of small amounts of Cu in the order of 1 kg Cu ha-1 will satisfy the Cu requirement of a crop and, over a period of years, have the same effect as a single broadcast and incorporated application. We tested this hypothesis in a number of experiments aimed at assessing the effectiveness of seedrow placement of a variety of Cu products (sulphate, oxysulphate and chelated) at various rates (0 to 4 kg Cu ha-1) in the year of application, its residual effect after four annual applications and whether it can be combined with foliar Cu applications to provide an agronomic and economic solution both in the short and longer terms. Annual seedrow applications of up to 4 kg ha-1 were both agronomically and economically inferior to broadcasting and incorporation of 4 kg ha-1 as Cu sulphate; the former provided a statistically significant grain yield increase only in 3 of 10 site-years and only when the Cu fertilizer was in sulphate or chelated forms. However, yield increases thus obtained were neither economical nor as good as those obtained with broadcast and incorporated copper sulphate. The residual effects of seedrow-applied Cu at rates up to 4 kg ha-1 were very small compared to a single, 4-yr old broadcasting and incorporation of 4 kg Cu ha-1, and were obtained primarily after 3 yr of annual applications and with sulphate or chelated products only. However, average yield increases as a result of residual effects in the fifth year were approximately 35% of those obtained with broadcasting and incorporation. Combining seedrow with foliar applications did not have any agronomic or economic advantage, since most benefit arose from the latter. Key words: Broadcast and incorporation, sulphate, oxysulphate, chelate, residual
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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 | 0.001 |
| 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 | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".