Evaluation of species selection and management decisions for fall seeded cover crops in Manitoba
Notice bibliographique
Résumé
There is limited local research available on cover crops in the eastern Canadian Prairies, including Manitoba. Cover crops are an agronomic practice in which plants are used to cover the soil for ecosystem benefits, rather than for market. Cover crops are often seeded and managed outside the conventional growing season, as to not displace cash crops. Ecosystem benefits (e.g. soil erosion control, N retention, weed suppression) can only be realized when there is sufficient cover crop establishment and growth. Cover crop performance depends on the overlapping influences of species selection and management decisions made in the context of a particular location. The limitations of GDD accumulation and precipitation amounts and timing in Manitoba present unique challenges when making cover crop decisions. The objective of this thesis was to compare cover crop decisions and to evaluate how these decisions affected the performance of different fall seeded cover crops in Manitoba. In addition, the impact of fall seeded cover crops on following cash crops was determined. This was achieved through three research studies. The first research study compared seven cover crop species, plus one mixture, seeded at three different dates in the fall. Two site-years were dry and two site-years were wet. Emergence, biomass production, C:N ratio, and ground cover were similar between winter killed cool season cover crop species when seeded around September 1. The second research study evaluated the effects of fall seeded cover crops on a spring wheat (Triticum aestivum L.) test crop. Three cool season annuals, one winter annual, and one cover crop mixture were seeded in the fall. Winter killed cover crops had no effect on the test crop. Fall rye (Secale cereale L.) and the mixture that contained fall rye had a negative effect on wheat density and wheat yield. The third research study compared fall rye cover crop termination timings prior to soybean (Glycine max (L.) Merr.) and edible bean (Phaseolus vulgaris L.). Managing the living cover crop in the spring with strip tillage removed the soybean yield penalty caused by late fall rye termination but only slightly improved edible bean yield. These results highlight the opportunity for using winter killed fall seeded cover crops in Manitoba with minimal risk to a following small grain crop. Fall rye used as a cover crop prior to spring wheat and edible bean requires termination prior to planting. Soybean can be planted green into fall rye with strip tillage. Results from this research show that there are opportunities for fall seeded cover crops in Manitoba cropping systems and will provide guidance for cover crop decision making. Future research under these environmental conditions should explore cover crop performance and thresholds for ecosystem benefits in Manitoba.
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 | 0,001 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| 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 ».