Late-season fertilization of <i>Picea mariana</i> seedlings: intensive loading and outplanting response on greenhouse bioassays
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
Traditional greenhouse culture involves a late-season hardening period that withholds irrigation and fertilization from black spruce seedlings to promote frost-hardiness. Since nutrient uptake is limited without supplemental fertilization, growth during hardening may lead to internal nutrient dilution, a condition detrimental to field performance of seedlings. We examine whether late-season fertilization, applied as intensive loading, will counter dilution and build up nutrient reserves in seedlings reared conventionally or nutrient loaded before hardening. A mixed NPK fertilizer delivering 0, 12, 24, or, 48 mg Nseedling -1 for 9 weeks after bud set was tested. Root and shoot dry mass increased as much as 104 and 42% during hardening. Seedling biomass, however, was unchanged by late-season fertilization, but N uptake was increased 44-167% signifying induced luxury consumption. Extra K supplementation of treatments averted K dilution in plant tissues often occurring with high N addition. A 13-week outplanting trial on intact soil bioassays retrieved from a boreal site showed that growth and nutrient allocation were significantly enhanced by larger N reserves built up after intensive nutrient loading. About 72-80% of N required for new shoot growth was met from internal cycling, demonstrating the capacity of loading to enhance retranslocation. Intermediate loading (24 mg N) was most effective in promoting N accumulation and outplanting growth of both seedling types. Survival was reduced (30%) only at the highest dose. Study results demonstrate the potential advantage of these practices to improve growth of newly planted seedlings on northern forest sites. black spruce / hardening period / nitrogen / nutrient loading / retranslocation / super-loading Rsum -Fertilisation tardive de semis de Picea mariana : apport intensif et rponse aprs plantation en serre d'essais biologiques. Les cultures traditionnelles en serre comportent une priode tardive d'endurcissement qui retarde l'irrigation et la fertilisation des semis de Picea mariana pour promouvoir l'endurcissement au froid. Puisque le prlvement de nutriments est limit sans supplmentation de fertilisation, la croissance pendant la priode d'endurcissement peut conduire une dilution interne des nutriments, une situation prjudiciable pour les performances au champ des plants. Nous avons examin si la fertilisation tardive, applique par des apports massifs peut contrebalancer la dilution et accrotre les rserves de nutriments dans les semis levs conventionnellement ou les nutriments apports avant l'endurcissement. On a test un mlange de fertilisant NPK librant 0,12, 24 ou 48 mg d'azote par semis pendant 9 semaines aprs le dbourrement. Le poids sec des racines et des pousses s'est accru de 104 et 42 % pendant l'endurcissement. Cependant la biomasse des semis a t inchange par une fertilisation tardive, mais le prlvement d'azote s'est accru de 44 167 %, indiquant une consommation de luxe. Une supplmentation en K vite une dilution en K des tissus, ce qui arrive souvent avec un apport important d'azote. Un essai 13 semaines sur un sol pour essais biologiques, extrait d'une station borale, a montr que la croissance et l'allocation des nutriments taient significativement augmentes par de grandes rserves d'azote accumul aprs des apports intensifs de nutriments. Environ 72 80 % de N requis pour la croissance des nouvelles pousses provenaient du cycle interne, dmontrant l'importance des apports pour augmenter les retranslocations. Un apport intermdiaire (24 mg N) tait plus efficace pour promouvoir l'accumulation de N et la croissance des deux types de semis. La survie a t rduite (30 %) seulement pour la plus forte dose. Les rsultats de cette tude ont dmontr l'avantage potentiel de ces pratiques pour l'amlioration de la croissance des semis dans les stations forestires du Nord.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it