Soil-available phosphorus as evaluated by desorption techniques and chemical extractions
Bibliographic record
Abstract
The P-supplying power of the fine-textured soils from Abitibi-Temiscaming (Quebec, Canada) has never been investigated. Anion exchange membranes (AEM), the electro-ultrafiltration (EUF) technique and chemical extractions were used to describe their P status. Phosphorus was desorbed from four soils that had received 52.4 kg P ha–1 yr–1 from 1994 to 1996 and from unfertilized soils. The cumulative amount of P desorbed in 75 min by EUF from unfertilized soils varied from 10 to 69 mg P kg–1. Averaged over all sites and treatments, the amount of soil P extracted by different methods ranged from 1.0 to 18.9 mg P kg–1. The cumulative grass P uptake was significantly related to P desorbed by all methods (0.39 < r < 0.84). A close relationship between grass P uptake and PAEMs indicated the adequacy of the AEMs to determine plant-available P in Abitibi-Temiscaming soils. A high degree of linearity (0.97 < R2 < 0.99) of the EUF-P desorption curves at 200 V and 20°C with time was obtained. This indicates that soils have a high capacity to buffer removal of P from soil solution with reserve P. The EUF technique has shown that these soils hold very large inorganic P reserves and this may explain the lack of grass response to P fertilizers. Key words: Anion exchange membranes, grass-P uptake, P-desorption, Mehlich3-P, Olsen-P.
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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
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".