Effect of time and rate of nitrogen, sulfur and boron application on canola growth in southwestern Québec
Notice bibliographique
Résumé
Canola (Brassica napusL.) seeds have a high oil content (> 40 %), the lowest saturated fat concentration (6.8%) among the vegetable oils, plus low erucic acid and glucosinolate levels, making this crop highly valuable in the oilseed industry. Québec, a province where little canola is currently produced, has considerable potential to expand canola cultivation and, in doing so, strengthen the provincial agricultural sector. However, at this time there are no well-founded fertility recommendations for canola production in southwestern Québec; there is a lack of sufficient data on canola responses to nitrogen (N), sulfur (S) and boron (B). Therefore, field studies were conducted in 2011 and 2012 to determine the optimum rate and timing of N fertilizer additions, and also the best rates of S and B application under southwestern Québec conditions. In 2011, factorial combinations of four levels of N [0, 50, 100 (or 50 + 50) and 150 (or 50 + 100) kg ha-1], two levels of S (0 and 20 kg ha-1), and three levels of B (0, 0.5 foliar spray at 20% flowering stage, and 2 kg ha-1 soil applied before sowing) were tested. Single doses of N fertilization (50, 100, 150 kg ha-1) were all applied before sowing. Split N fertilization was also evaluated at two levels: 100 kg ha-1 (50 + 50 kg ha-1) and 150 kg ha-1 (50 + 100 kg ha-1), where the first dose of 50 kg N ha-1 was applied before sowing, and the remainder was side-dressed at the 3-4 leaf stage. In 2012, two additional treatments were added, one applied as 20 kg S ha-1, 0.5 kg B ha-1 and 200 kg N ha-1, and the other as 20 kg S ha-1, 0.5 kg B ha-1 and 50 + 150 kg N ha-1. In 2011, N fertilization had positive effects on dry biomass, leaf area, plant height, seeds silique-1, harvest index, yield, and seed protein content, but a negative effect on seed oil content. The optimum N rate was 150 kg N ha-1, resulting in the highest seed yield and good seed quality. In 2012, canola did not respond as strongly to fertilizer additions as in 2011, apparently because of lower established plant densities. Application of fertilizer N affected fewer variables in 2012: 1000-seed weight, and harvest index, seed oil content and seed protein content. Of the four blocks in the 2012 experiment, only block four had a reasonably high average plant population density. For block four, the yield data was curvilinearly and positively correlated with N rate (R² = 0.5702, P < 0.0001), with peak yield occurring at 150 kg N ha-1. Canola growth was often not affected by the time of N application. In 2011, there was a S x B interaction for 1000-seed weight, in that the effect was positive with foliar application of 0.5 B kg ha -1 and negative when 2 kg B ha-1 was soil-applied). Boron alone increased 1000-seed weight in 2012. Our results indicated that S and B levels in the soils used were probably sufficient for canola production. Plant height was decreased (2.9 %) by S application at 20 kg ha-1 in 2011. In conclusion, our data suggest that the best N application regime for canola production in southwestern Québec may be a single application at 150 kg N ha-1; this produced the highest seed yield without sacrifice of seed quality. Sulfur and B additions may not be required for canola production in southwestern Québec.
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Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,001 |
| 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 | 0,001 | 0,000 |
| Communication savante | 0,001 | 0,000 |
| Science ouverte | 0,001 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 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
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