Nitrogen concentration of cauliflower organs as determined by organ size, N supply, and radiation environment

verfasst von: H. Kage, C. Alt, H. Stützel
Abstract: Data from field experiments carried out in three consecutive years under contrasting N supply and radiation environment altered by artificial shading were used to identify (a) the relationship between N concentration and organ size under conditions of unrestricted N supply and (b) critical levels of soil nitrate (Nmin_crit), where nitrogen concentration of cauliflower organs begin to decline because of N limitations. The decline of N concentrations in cauliflower was analysed at different levels of morphological aggregation, i.e., the whole shoot level, the organ level (leaves, stem, and curd), and within different leaf groups within the canopy. Nmin_crit values (0-60 cm soil depth) for total nitrogen concentration of cauliflower organs leaves, stem and curd were estimated at 85, 93 and 28 kg N ha ^-1, respectively. Within the canopy, Nmin_crit values for total N of leaves increased from the top to the bottom from 44 to 188 kg N ha^-1. Nmin_crit values for protein N in leaves from different layers of the canopy were much lower at around 30 kg N ha ^-1, without a gradient within the canopy. It is discussed that these differences in Nmin_crit values are most likely a consequence of N redistribution associated with nitrogen deficiency. The decline of average shoot nitrogen concentrations, [Nm] (%N DM), with shoot dry matter, W _sh, (t ha^-1) under conditions of optimal N supply was [Nm]= 4.84 (±0.071) W_sh ^{-0.089(±0.011)}, r²=0.67 (±S.E.). The reduction of radiation intensity by artificial shading (60% of control) had no significant influence on total nitrogen concentrations of leaves and only a small influence on protein nitrogen concentrations in lower layers of the canopy. The leaf nitrate nitrogen fraction of nitrogen, f_nitr (-), within the canopy decreased linearly with increased average incident irradiance in different canopy layers (I_av, W PAR m^-2) (f_Nitr. = 0.2456(±0.0188)-0.0023(±0.0004)I_av, r² = 0.67.
Organisationseinheit(en): Institut für Gartenbauliche Produktionssysteme
Externe Organisation(en): Christian-Albrechts-Universität zu Kiel (CAU)
Typ: Artikel
Journal: Plant and soil
Band: 246
Seiten: 201-209
Anzahl der Seiten: 9
ISSN: 0032-079X
Publikationsdatum: 10.2002
Publikationsstatus: Veröffentlicht
Peer-reviewed: Ja
ASJC Scopus Sachgebiete: Bodenkunde, Pflanzenkunde
Elektronische Version(en): https://doi.org/10.1023/A:1020627723616 (Zugang: Geschlossen)

BibTeX

@article{6a286f07924b4992994ffa13e9c3e449,
title = "Nitrogen concentration of cauliflower organs as determined by organ size, N supply, and radiation environment",
abstract = "Data from field experiments carried out in three consecutive years under contrasting N supply and radiation environment altered by artificial shading were used to identify (a) the relationship between N concentration and organ size under conditions of unrestricted N supply and (b) critical levels of soil nitrate (Nmincrit), where nitrogen concentration of cauliflower organs begin to decline because of N limitations. The decline of N concentrations in cauliflower was analysed at different levels of morphological aggregation, i.e., the whole shoot level, the organ level (leaves, stem, and curd), and within different leaf groups within the canopy. Nmincrit values (0-60 cm soil depth) for total nitrogen concentration of cauliflower organs leaves, stem and curd were estimated at 85, 93 and 28 kg N ha -1, respectively. Within the canopy, Nmincrit values for total N of leaves increased from the top to the bottom from 44 to 188 kg N ha-1. Nmincrit values for protein N in leaves from different layers of the canopy were much lower at around 30 kg N ha -1, without a gradient within the canopy. It is discussed that these differences in Nmincrit values are most likely a consequence of N redistribution associated with nitrogen deficiency. The decline of average shoot nitrogen concentrations, [Nm] (%N DM), with shoot dry matter, W sh, (t ha-1) under conditions of optimal N supply was [Nm]= 4.84 (±0.071) Wsh -0.089(±0.011), r2=0.67 (±S.E.). The reduction of radiation intensity by artificial shading (60% of control) had no significant influence on total nitrogen concentrations of leaves and only a small influence on protein nitrogen concentrations in lower layers of the canopy. The leaf nitrate nitrogen fraction of nitrogen, fnitr (-), within the canopy decreased linearly with increased average incident irradiance in different canopy layers (Iav, W PAR m-2) (fNitr. = 0.2456(±0.0188)-0.0023(±0.0004)Iav, r2 = 0.67.",
keywords = "Brassica oleracea L. botrytis, Cauliflower, Nitrogen concentration, Nmin, Organ size, Radiation intensity, Shading",
author = "H. Kage and C. Alt and H. St{\"u}tzel",
note = "Funding Information: The technical assistance of E. Diedrich, I. Lippert and ML. Lehmann is gratefully acknowledged. Financial support was gratefully given by the Deutsche Forschungsgemeinschaft. Two unknown reviewers gave valuable comments for improving the manuscript.",
year = "2002",
month = oct,
doi = "10.1023/A:1020627723616",
language = "English",
volume = "246",
pages = "201--209",
journal = "Plant and soil",
issn = "0032-079X",
publisher = "Springer Netherlands",
number = "2",
}