Nitrogen Management Effects on Spring Wheat Yield and Protein Concentration Vary with Seeding Date and Slope Position
Bibliographic record
Abstract
Efficient N fertilizer can improve economic returns and reduce environmental risk. This study evaluated effects of fertilizer rate, source, timing and placement combinations on spring wheat ( Triticum aestivum L.) yield and protein concentration under varying environmental conditions created by differing slope position and seeding dates. Grain yield and protein responses to N management were evaluated for 3 yr at two locations near Brandon, MB, Canada. Grain yield was generally higher by up to 0.9 t ha −1 and protein lower by up to 20 g kg −1 on lower vs. upper slope positions. Grain yield was higher by up to 0.7 t ha −1 and protein concentration lower by 20 g kg −1 with early vs. late seeding. While grain yield and protein both usually increased with N application, by up to 25 and 20%, differences among fertilizer treatments were infrequent. In 2 site‐years, grain yield was lower with fall‐ than spring‐banded urea and the use of fall‐banded controlled release urea (CRU) reduced N losses and led to yields intermediate between fall‐ and spring‐banded urea. Where differences occurred among fertilizer treatments, yield was generally highest with spring side‐banded urea. However, protein occasionally increased with use of CRU vs. urea fertilizer. Spring side‐banded urea, although less costly than enhanced efficiency fertilizers or split N applications, produces both yield and protein concentrations as high or higher than a range of enhanced efficiency fertilizer products or split applications of N, and is a good N management option under environmental conditions in southwestern Manitoba. Core Ideas Benefits of controlled release fertilizers are low where N losses are low In‐soil banding of N is an effective management practice Use of urease inhibitors may not overcome loss of efficiency for surface application as compared to in‐soil banding Spring in‐soil bands are as or more effective than split applications of N in increasing spring wheat yield under common prairie conditions When banded in the fall, controlled release urea can be more effective than uncoated urea where environmental conditions promote N losses
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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 | 0.000 | 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".