Feasibility of applying all nitrogen and phosphorus requirements at planting of no-till winter wheat
Notice bibliographique
Résumé
The recent advances in no-till seeding technology are providing new N management options for crop production on the prairies. The objectives of this study were to evaluate the potential interaction between P and N fertilizer on winter wheat production in a one-pass seeding and fertilizing system and to determine the feasibility of side-banding all N requirements using urea or anhydrous ammonia at planting as compared with the current practice of broadcasting ammonium nitrate early in the spring. Three forms of N fertilizer (urea, anhydrous ammonia, ammonium nitrate), three rates of N (50, 75 and 100 kg ha–1) and three rates of P (0, 9 and 17 kg P ha–1) were investigated. Urea and anhydrous ammonia were applied during the seeding operation, whereas ammonium nitrate was broadcast the following spring. Applying P fertilizer to the side and below the seed at planting with rates > 9 kg Pha–1 increased grain yield in 3 out of 6 site-years when ammonium nitrate was broadcast early in the spring. The positive yield response to P corresponded to soil test levels of 24 kg P ha–1. With soil test levels greater than 34 kg P ha–1, grain yield response to P fertilizer was not observed. When urea was banded at planting, together with P fertilizer, the yield increases with the increased P rates was shown only in 1 out of 6 site-years. At 5 of th e 6 site-years, grain protein concentration was not affected by P fertilizer; while for 1 site-year, the high rate of P fertilization decreased grain protein concentration. Responses of total grain N and P yields to P fertilization were parallel to the corresponding responses of P fertilization to grain yield, and were rarely associated with N or P concentrations in the grain. Applying N fertilizer at rates of 50 to 100 kg N ha–1 increased winter wheat grain yields by 3 to 8% in 3 out of 6 site-years. The high N rates increased grain protein concentrations in all 6 site-years. Grain protein concentration was 6% greater with N fertilizer applied as ammonium nitrate in early spring than when banding urea or anhydrous ammonia at planting. More consistent improvements in grain yield and grain protein concentration were obtained when the N fertilizer was applied as ammonium nitrate in the spring. Further research is required to determine the benefits of applying some of the crop’s N fertilizer requirements at planting, to reduce the risks of N stresses when the spring application is delayed because of adverse weather or soil conditions. Key words: Ammonium nitrate, anhydrous ammonia, grain yield, nitrogen timing, phosphorus, protein, urea
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Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
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 | 0,000 | 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) | 0,001 | 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 source (Gemma direct ou Codex distillé), 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 ».