Modeling the adsorption of phosphate in agricultural soils of Southern Ontario
Bibliographic record
Abstract
This thesis is an investigation of the behaviour of phosphates (P) in southern Ontario agricultural soils with the development of a soil assemblage model. The model was used to predict P availability in soils with varying pH and soil texture. The model considers the aqueous speciation of P and the complexation of P onto two reactive surfaces: clay minerals and iron oxides. Clays were separated from four representative soils from southern Ontario and were used to develop the soil assemblage model. Goethite was chosen as the representative iron oxide and was synthesized in the laboratory. Clay and goethite proton and P binding constants were determined with potentiometric titrations and batch adsorption experiments. All data was analyzed with the program FITEQL. The model was tested with soils sampled from an agricultural field in Parkhill, Ontario, which were characterized for soil texture, pH, and calcium, magnesium, dissolved organic carbon, extractable iron and P content. Model predictions were most accurate for the sites with the lowest soil clay content and in general were accurate around the actual soil pH of the site soils.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.000 |
| Scholarly communication | 0.001 | 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".