Quantifying carbon sequestration in a conventionally tilled crop rotation study in southwestern Saskatchewan
Notice bibliographique
Résumé
In this study we used results from 10 cropping systems in a 37-yr field experiment being conducted on a medium-textured Orthic Brown Chernozem in semiarid southwestern Saskatchewan, in which soil organic carbon (SOC) had been sampled in 7 different years, to quantify trends and changes in SOC in the 0- to 15-cm depth. We tested the effectiveness of three models: Century, the Introductory Carbon Balance Model (ICBM), and the Campbell model to predict the measured values. The 10 cropping systems allowed us to assess the influence of cropping frequency, fertilization and crop type on SOC and, because growing season weather was distinctly more humid in the final 12 yr of the study, we were able to assess the impact of weather. In this soil on which a fallow-wheat (Triticum aestivum L.) (F-W) rotation was maintained for the previous 60 yr, SOC remained fairly constant under normal weather for the first 20 yr of the study for the systems that were frequently fallowed, except for fallow-fall rye (Secale cereale L.)- wheat (F-Rye-W). In contrast, in the final 12 yr, SOC increased in all systems in response to increased C inputs from crop residues associated with improved precipitation. SOC gains were greater for well-fertilized extended crop rotations such as continuous wheat (Cont W) and wheat-lentil (Lens culinaris Medikus) (W-Lent) and the F-Rye-W systems receiving N and P than for the F-W, F-W-W, F-Flax (Linum usitatissimum L.)-W (F-Flx-W) receiving N and P, and Cont W receiving only P. SOC was also greater for well- fertilized than for poorly fertilized systems. The ICBM and Campbell models performed well in simulating SOC trends, partly because they used measured grain yields to estimate C inputs. However, the Century model was less effective in its simulation of SOC especially for the fallow-containing systems due to its difficulty in estimating spring soil water and crop yields. We showed how grain yields can be used, together with coefficients of conversion of C inputs from crop residues to SOC, to estimate SOC changes. Using these relationships, and assuming the coefficient of conversion of C inputs to SOC sequestered is 15% for well-fertilized extended rotations, or 10% for well-fertilized frequently fallowed spring-seeded systems, one can make reasonable first estimates of the impact of management on C sequestration in degraded soils of the semiarid prairies. Key words: ICBM model, Century model, Campbell model, soil organic C, N and P fertilizer, cropping frequency
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,003 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».