Quantification des pertes en phosphore en milieu agricole - outil LoPhos.
Bibliographic record
Abstract
La contamination des cours d'eau par le phosphore (P) est une problématique de plus en plus préoccupante en milieu agricole. En 1998, le ministère de l'Environnement du Québec a subventionné le développement d'un outil de calcul des pertes de P à l'environnement en provenance des activités agricoles. L'outil développé s'appelle LoPhos et est applicable dans les conditions agro-clirnatiques du Québec. LoPhos utilise une approche basée sur des régressions linéaires et des coefficients de perte moyens. Cette approche a l'avantage d'utiliser directement les données les plus récentes de la littérature et d'intégrer l'ensemble des processus dominant les pertes de P en milieu agricole. Le présent article a pour objectif de présenter les relations mathématiques développées à partir des pertes de P mesurées sur des fermes sous différentes conditions, et intégrées dans l'outil LoPhos. Dans LoPhos, les pertes de P au champ par ruissellement, érosion, drainage et lessivage sont prises en compte. Les données de la littérature ont permis de développer des relations pour calculer distinctement l'effet du P épandu annuellement et du P contenu dans le sol. Une relation tenant compte de la rétention du P par les bandes riveraines a aussi été obtenue. Finalement, les pertes de P aux bâtiments en provenance des cours d'exercice, des amas de fumier, des sites de compostage, ainsi que les rejets de P dans les eaux usées de laiterie sont calculées à l'aide de coefficients. L'outil développé répond ainsi au besoin des professionnels qui doivent évaluer le risque de contamination associé à l'entreposage des fumiers, à la fertilisation et à la culture des sols. \n \n Abstract \nWater pollution by agricultural phosphorus (P) is an increasing concern problern in rural areas. ln 1998, the Quebec rninistry of Environrnent sponsored the developrnent of a tool to predict P losses to the environrnent frorn agricultural activities. The rnathernatical tool which was developed is narned LoPhos. lt uses an approach based on linear regressions and average loss coefficients, and is applicable to the agro-clirnatic conditions of the province of Quebec. This approach uses data frorn the rnost recent literature and integrates the rnost important processes involved in agricultural P losses. This paper presents the rnathernatical relations integrated in LoPhos and obtained frorn P losses rneasured on farrn under different conditions. This review provided ail the data necessary for developing LoPhos. ln this tool, P losses in the field corne frorn runoff, erosion, drainage and leaching. The available data frorn previous studies provide sufficient information to develop equations to calculate separately the effects of fertilizer P and of soil P. An equation taking into account P retention by riparian zones was also identified. Finally, P losses frorn exercise lots, rnanure piles, cornposting sites, as well as P tosses to the environrnent frorn dairy farrn wastewater are calculated using coefficients. LoPhos rneets the needs of professionals who must evaluate pollution risks associated with fertilization practices, soil cultivation and management of rnanure stocks.
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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 | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 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 | 0.000 |
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".