Life cycle inventory of four wheat production systems in Québec
Bibliographic record
Abstract
Abstract. Best agricultural practices can be adopted to lower the environmental impact of wheat production while maintaining productivity. The work done in this project has been entrusted by a grain buyer who wished to compare the economic and environmental performance of four wheat production systems. A “cradle-to-harvest” life cycle inventory (LCI) was done to assess the environmental impact of four production systems (intensive, conventional, integrated and organic) for wheat in Québec. Data used in the project come from plots established on farms that were accustomed to sell their wheat to the grain buyer. Producers were asked to provide data for their cultural operations, fertilizer and pesticide application strategies, soil conditions/texture and yields. This paper focuses on the cradle-to-harvest stages for greenhouse gas emissions (GHG), including the production of agricultural inputs and the associated emissions. GHG were estimated for all cultural operations, as well as all processes upstream of the farm like manufacturing and transportation of machinery, diesel, fertilizers, pesticides and seeds. Nitrogen and phosphorus losses were computed for processes occurring on the farm following the application of manure or mineral fertilizers. Per hectare of land use, GHG emissions were 1,824 kg CO2e for the organic system, 3,506 kg CO2e for the integrated system, 3,614 kg CO2e for the conventional system and 3,750 kg CO2e for the intensive system. Per ton of wheat produced, GHG emissions for organic, integrated, conventional and intensive production systems were respectively 629 kg CO2e, 938 kg CO2e, 852 kg CO2e and 793 kg CO2e. Plots with a higher dose of nitrogen generally have higher GHG emissions. There was little difference between productions systems in terms of N losses because dozes of nitrogen applied were in the same range. N2O emissions were lower for the organic system because three of the plots were not fertilized. PO43- leaching to surface water was higher for the organic system due to higher doses of phosphorus coming from manure. Results presented per ton of wheat produced showed that the emissions were lower for higher yields.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.003 |
| 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) | 0.005 | 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".