Economics of N and P fertilization to restore wheat yields on three artificially eroded sites in southern Alberta
Bibliographic record
Abstract
An important economic concept in the evaluation of soil conservation is the ease with which production inputs can be substituted for one another. This concept and economic optimum application rates of N and P fertilizer for wheat grown after fallow were applied to three artificially eroded soils in southern Alberta. Each site had topsoil removed to depths of 0, 10 and 20 cm. Four rates of N (0, 50, 75 and 100 kg ha−1) and three rates of P (0, 11 and 22 kg ha−1) were applied to each eroded depth. There were four replications. Fertilizer N and P did not easily substitute for the loss of topsoil. The economic optimum level of N and P was nearly constant across depths of eroded topsoil. Increases in fertilizer N and P applied to eroded soils were primarily to replace lost soil nutrients. It was not economical to apply inorganic fertilizer on these eroded soils at rates that would restore grain yields. Key words: Eroded soil, economics, inorganic fertilizer, wheat
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| 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 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 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 source (direct Gemma or distilled Codex), 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".