Nitrous Oxide Production from Urea Granules of Different Sizes
Bibliographic record
Abstract
Abstract Three laboratory experiments were conducted to determine if urea granule size or a high concentration of urea prills influence N 2 O production in soil. Urea hydrolysis results in a localized increase in soil pH and an increase in ammonia concentration. Such conditions may adversely affect the nitrification process, thereby increasing the N 2 O to NO − 3 product ratio. Also, if anaerobic conditions should occur, the N 2 O to N 2 product ratio during denitrification may increase. In general, under aerobic conditions, increasing the urea granule size from a powder to prill (commercial granules) and to larger granules resulted in increased N 2 O production. The increase in N 2 O production as granule size increased was accompanied by an increase in NO − 2 concentration. The accumulation of NO − 2 and the lower rates of disappearance of NH + 4 , or appearance of NO − 3 , indicated that the nitrification process was adversely affected. The appearance of N 2 O was delayed with increasing granule size. A high concentration of urea prills produced a similar but greater effect than large granules. The appearance and rapid production of N 2 O was closely related to the rapid disappearance of hydroxylamine and the presence of NO − 2 . The failure to detect hydroxylamine in urea granule‐treated soil may have been due to its rapid oxidation to N 2 O. The proportion of the added urea N transformed to N 2 O increased with granule size but did not exceed 1.24% of the urea added. A high concentration of urea prills resulted in 2.80% converted to N 2 O−N.
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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) | 0.001 | 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 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".