Delaying application and injecting nitrogen fertilizer with urease and nitrification inhibitors decreased nitrous oxide emissions and enhanced corn yields
Bibliographic record
Abstract
Abstract Early season nitrous oxide (N 2 O) emissions following nitrogen fertilizer application can be significant if spring rains lead to anaerobic conditions before the crop is established and able to utilize the applied N. However, delaying fertilizer application by 4‐5 weeks after planting usually results in warmer temperatures which promote ammonia (NH 3 ) volatilization losses. This 3‐year study on a clay loam soil compared NH 3 losses, N 2 O emissions, and corn ( Zea mays L.) grain yields for pre‐plant urea ammonium nitrate (UAN) injection versus side‐dress UAN injection using no inhibitors, a urease inhibitor, or a urease and nitrification inhibitor. Side‐dress N‐application resulted in 13% greater corn grain yields compared to pre‐plant N application when averaged over the inhibitor treatments. Pre‐plant UAN with a urease inhibitor had 59% greater N 2 O emissions (2.15 kg N ha −1 ) than pre‐plant injected UAN with a urease and nitrification inhibitor (1.35 kg N ha −1 ); pre‐plant UAN injection with no inhibitors produced intermediate N 2 O losses (1.89 kg N ha −1 ). Delaying UAN application to side‐dress in 2015, the year with above‐normal spring precipitation, decreased N 2 O emissions (1.24 kg N ha −1 ) by 52% compared to pre‐plant UAN (2.56 kg N ha −1 ); however, side‐dress application had minimal impact on N 2 O in the subsequent 2 years which had drier spring conditions. The dual urease and nitrification inhibitor treatment reduced yield‐scaled N 2 O emissions by 37% compared to urease only when averaged over the timing treatments. Side‐dress N application reduced yield‐scaled N 2 O emissions by 28% compared to pre‐plant application when averaged over the inhibitor treatments. Urease plus nitrification inhibitors combined with side‐dress UAN application increased corn yields and decreased N 2 O losses, whereas urease inhibitors alone increased N 2 O emissions.
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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".