Direct chemical speciation of soil phosphorus in a Saskatchewan Chernozem after long and short-term manure amendments
Bibliographic record
Abstract
Chemical form of phosphorus (P) in soils influences both plant accessibility and solute transport of P. Soil P speciation receiving inorganic and organic fertilizers is extensively studied to address a range of agronomic and environmental concerns. It is known inorganic P sources react over long time scales in soils, but relatively few studies have focused upon long-term P speciation changes in soils receiving organic amendments. This study was conducted to address this gap by providing detailed information on the speciation of P in agricultural soils from short- (2 yr) and long-term (11 yr) applications of liquid hog manure (LHM) and solid cattle manure (SCM) made at a field research site. Chemical speciation was performed with a combination of laboratory-based soil test P extraction methods and solid-state synchrotron-based techniques. There was clear evidence that initial phosphate minerals in the manures rapidly transform into new phases after short-term soil application. The X-ray absorption near edge spectroscopy results for SCM soil samples were consistent with high solubility (likely Mg-substituted) dicalcium phosphate minerals and phosphate (PO4) adsorption species present after short-term period, whereas long-term SCM application resulted in transformation of soil phosphate into more crystalline calcium phosphate minerals. In contrast, phosphate speciation after short term of LHM application revealed predominantly magnesium phosphate and adsorbed P compounds. Soils under long-term LHM amendment still had phosphate speciation dominated by poorly crystalline dicalcium phosphate minerals. This suggests that the manure form plays a strong role not only in short-term plant availability but also in long-term P speciation.
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 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 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 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".