Relationship between concentration of isoflavones in soybean grain and potassium fertilization
Notice bibliographique
Résumé
Soybean grain contains isoflavones that may prevent various human diseases. Previous studies in Canada found that K fertilization and high grain K concentration can result in increased isoflavones concentration in grain, but effects were inconsistent across sites and soil-test K (STK) levels. The objective of this study was to assess (1) effects of K fertilization on the concentration of isoflavones and K in soybean grain and (2) relationships between soybean grains K concentration, isoflavone concentration, and yield. The study was based on analyses of grain collected from selected treatments and years of six Iowa long-term experiments that investigated effects of K fertilization and placement methods on soybean yield. Four experiments evaluated K placement methods for no-till soybean in rotation with corn (Zea mays, L.) from 1994 to 2001 at Iowa research farms located near Nashua, Kanawha, Lewis, and Sutherland. Two experiments evaluated broadcast K rates from 1976 until 2001at research farms near Ames and Kanawha. Grain samples were collected from two replications of three treatments from 17 site-years. Treatments selected from the placement trials were a control (no K) and 66 kg ha-1 yr-1 broadcast or deep-banded 15-20 cm depth, although at (two sites) Kanawha and Nashua grain also was collected from plots receiving 33 kg K ha-1 yr-1. Treatments selected from the other trials were a control and 67 or 100 kg K ha-1 yr -1. Soil samples were collected before planting soybean from the control plots for STK analyses. Grain was analyzed for concentration of K and 12 isoflavones. Potassium fertilization did not increase (P ≤ 0.05) grain yield, K concentration, or isoflavones concentration at sites where STK was above optimum for soybean. However, it increased grain K concentration and uptake consistently and yield and isoflavones concentration less consistently in other sites with STK Low or Optimum for soybean. On average across responsive sites, K fertilization increased K uptake 20%, yield 11%, K concentration 10%, and total isoflavones 6%. Isoflavones response to K was explained by response of total daidzein and genistein (total glycitein did not respond). Relationships between STK, concentration of K and isoflavones in grain, and grain yield often were positive and significant within sites but seldom across sites. Potassium fertilization increased yield and isoflavones concentrations only when STK was below optimum levels for crops but did not increase yield or isoflavones concentrations in high-testing soils. Relationships within and across locations indicated that the concentration of isoflavones in grain decreased or was unrelated with grain K concentration. Therefore, grain K concentration alone is not a good index of potential effects of K fertilization on isoflavones concentration in soybean grain.
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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 ».