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Record W2791661023

Agricultural pesticide use trends in Manitoba and 2,4-D fate in soil

2012· dissertation· en· W2791661023 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

aboutThe title or abstract carries a Canadian signal from the geographic lexicon.
no affNo Canadian affiliation: this work is invisible to an affiliation-only frame.
No Canadian affiliation. An affiliation-only frame, the usual design, would never have seen this work. It is one of the works that make the case for inverting the frame.

Bibliographic record

VenueMspace (University of Manitoba) · 2012
Typedissertation
Languageen
FieldEnvironmental Science
TopicPesticide and Herbicide Environmental Studies
Canadian institutionsnot available
Fundersnot available
KeywordsAgriculturePesticideEnvironmental scienceGeographyWater resource managementArchaeologyAgronomyBiology
DOInot available

Abstract

fetched live from OpenAlex

In the last century, agricultural intensification on the Canadian prairies has resulted in increased pesticide use with the potential to expose non-target organisms to pesticides as a result of non-point source pollution. In order to minimize risk and implement programs and regulations that promote sustainable agricultural practices, information on the types of pesticides being used and their subsequent fate in soils is essential. In this study, pesticide use trends were summarized and Herbicide Risk Indicators (HRIs) were calculated for the 1996-2006 growing seasons; a time period in which genetically modified herbicide-tolerant (GMHT) crops were commercially adopted. This study also quantified the influence of soil moisture, temperature, slope position, and soil depth within the plough layer on 2,4-D [2,4-(dichlorophenoxy) acetic acid] fate in soil obtained from a cultivated undulating field in Southern Manitoba. Annual pesticide use varied slightly over the 11-year period, but overall, there were no significant increasing or decreasing temporal trends for herbicides, fungicides, or insecticides. Although the total mass of herbicides remained relatively consistent, there was a significant change in the types of herbicides applied associated with the increased adoption of GMHT-canola; the most significant trend being the increase of GLY, from 16% to 45% of the total herbicides used in 1996 to 2006, respectively. HRIs demonstrated that herbicides used in 2006, are on average, more soluble, but less persistent, less volatile, and less acutely toxic to mammals (inhalation and acceptable daily intake), aquatic invertebrates, fish and algae, than those applied in 1996. Although 2,4-D remains one of the top 10 herbicides applied to agricultural crops in Manitoba, there were no significant increasing or decreasing trends in 2,4-D use between 1996 and 2006. Results from the experimental studies revealed that 2,4-D mineralization half-lives (DT50) in soil varied from 3 days to 51 days with the total 2,4-D mineralization (MT) ranging from 5.8 to 50.9%, depending on soil moisture, temperature, slope position, and depth. Both DT50 and MT demonstrated a polynomial relationship with temperature, typical of a biological system with minimum, optimum, and maximum temperatures.

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.

Full frame distilled prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesMeta-epidemiology (narrow)
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.896
Threshold uncertainty score1.000

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.001
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

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.

Opus teacher head0.016
GPT teacher head0.197
Teacher spread0.180 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it