Evaluation of canopy reflectance technology to improve nitrogen application in corn
Bibliographic record
Abstract
Switching from uniform application of N fertilizers to spatial application based on crop need may reduce harmful environmental effects and fertilizer costs for producers. The objective of this study was to determine whether variable rate N application technology, based on the spectral reflectance of the crop canopy, can predict spatial corn nitrogen response as measured by delta yield. A GreenSeeker RT200 was used to measure Normalized Difference Vegetative Index (NDVI) on two main starter nitrogen treatments, 0 and 30 kg N ha-1, at the 6-7, 8, 10 and 11-12 leaf stages. Results show that the GreenSeeker system was unable to determine spatial nitrogen response as measured by delta yield in either starter treatment in either site-year with confidence. However, NDVI was able to predict corn grain yield and was also significantly correlated to Pre-sidedress soil Nitrogen Test values early on in the growing season. Overall the GreenSeeker optical scanning technology can not accurately predict spatial nitrogen requirements for Ontario corn production.
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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 | 0.001 |
| 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".