Bibliographic record
Abstract
Nitrogen (N) is one of the most important nutrients influencing both yield and grain quality,and N supply is one of the few production factors that can be controlled and which is known to effectively influence crop performance.Both SPAD reading and Dualex reading are shown to be highly correlated with leaf N concentration,and crop N status can be assessed through the SPAD reading and Dualex reading.The purpose of this study was to evaluate the suitable N rate at topdressing time.In order to evaluate the N application rates on SPAD reading and Dualex reading of corn after silking,corn field experiment was conducted with application of 45 kg N ha-1 at sowing and planting density of 79 000 plants ha-1 in 2008 on the L’Acadie experimental farm (Quebec,Canada).Topdressing N was performed with 0,34,68,101,135,169,and 203 kg N ha-1 at jointing stage.N-saturated reference plots with topdressing of 180 kg N ha-1 at 10 days after sowing,besides 45 kg N ha-1 at sowing,was established.With increasing topdressing N rates,SPAD reading,aboveground dry biomass and corn grain yield increased,and Dualex reading decreased.The SPAD-NSI of topdressing N treatments with 101,135,169,and 203 kg N ha-1 was always higher than 0.95 at all samplings dates.The Dualex-NSI of topdressing N treatments with 101 kg N ha-1 was higher than 0.95 from 18 d to 46 d;the Dualex-NSI of topdressing N treatments with 135,169,and 203 kg N ha-1 was also higher than 0.95 at all samplings dates.SPAD reading,Dualex reading,SPAD-NSI and Dualex-NSI were strongly correlated with topdressing N rates.The maximum yield was reached when topdressing N was 101 or 135 kg N ha-1 at jointing stage.When maximum yield was reached,any additional N was no significant effect on SPAD reading,Dualex reading,aboveground dry biomass and corn grain yield.Topdressing N rate of 101 or 135 kg N ha-1 was enough for corn growth after silking and getting maximum grain yield.There was no significant difference between splitting the N into two applications and N-saturated application on grain yield;however,splitting the N into two applica-tions significantly decreased the total N application rate and growers’ inputs.In the present study,the suitable topdressing N rate was 101 or 135 kg N ha-1 with 45 kg N ha-1 at sowing.SPAD and Dualex could be integrated to evaluate in-season N status of corn.
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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".