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Titolo:
Contrasted nitrogen utilization in annual C-3 grass and legume crops: Physiological explorations and ecological considerations
Autore:
Del Pozo, A; Garnier, E; Aronson, J;
Indirizzi:
Ctr Ecol Fonct & Evolut, CNRS UPR 9056, F-34293 Montpellier 5, France Ctr Ecol Fonct & Evolut Montpellier France 5 34293 Montpellier 5, France Concepcion Univ, Fac Agron, Chillan, Chile Concepcion Univ Chillan Chile oncepcion Univ, Fac Agron, Chillan, Chile
Titolo Testata:
ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY
fascicolo: 1, volume: 21, anno: 2000,
pagine: 79 - 89
SICI:
1146-609X(200001/02)21:1<79:CNUIAC>2.0.ZU;2-0
Fonte:
ISI
Lingua:
ENG
Soggetto:
RELATIVE GROWTH-RATE; N-2 FIXATION; USE EFFICIENCY; PLANT-GROWTH; SOIL-NITROGEN; GRAIN LEGUMES; LEAF NITROGEN; WINTER-WHEAT; FIELD PEA; CARBON;
Keywords:
interspecific comparisons; nitrogen use efficiency; nitrogen concentration; nitrogen productivity; photosynthesis;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Citazioni:
75
Recensione:
Indirizzi per estratti:
Indirizzo: Garnier, E Ctr Ecol Fonct & Evolut, CNRS UPR 9056, 1919 Route Mende, F-34293 Montpellier 5, France Ctr Ecol Fonct & Evolut 1919 Route Mende Montpellier France 5
Citazione:
A. Del Pozo et al., "Contrasted nitrogen utilization in annual C-3 grass and legume crops: Physiological explorations and ecological considerations", ACTA OECOL, 21(1), 2000, pp. 79-89

Abstract

Although it is well known that legumes have unusually high levels of nitrogen in both reproductive and vegetative organs, the physiological implications of this pattern have been poorly assessed. We conducted a literature survey and used data from two (unpublished) experiments on annual legumes andC-3 grasses in order to test whether these high nitrogen concentrations inlegumes are col-related to high rates of carbon gain. Three different temporal/spatial scales were considered: full growing season/stand, days to month/whole plant and seconds/leaf. At the stand level, and for plants grown under both extratropical and tropical settings, biomass per unit organic-nitrogen was lower in legume than in grass crops. At a shorter time scale, therelative growth rate per unit plant nitrogen ('nitrogen productivity') waslower in faba bran (Vicia faba var. minor cv. Tina) than in wheat (Triticum aestivum cv. Alexandria), and this was confirmed in a comparison of two wild, circum-Mediterranean annuals - Medicago minima, a legume, and Bromus madritensis, a grass. Finally, at the leaf level, a synthesis of published data comparing soybean (Glycine max) and rice (Oryza sativa) on the one hand, and our own data on faba bean and wheat on the other hand, demonstrates that the photosynthetic rate per unit leaf nitrogen (the photosynthetic nitrogen use efficiency) is consistently lower in legumes than in grasses. These results demonstrate that, regardless of the scale considered and althoughthe organic-nitrogen concentration in vegetative organs of legumes is higher than in grasses, this does not lead to higher rates of carbon gain in the former. Various physiological factors affecting the efficiency of nitrogen utilization at the three time scales considered are discussed. The suggestion is made that the ecological significance of the high nitrogen concentration in legumes may be related to a high nitrogen demand for high quality seed production at a time when nitrogen fixation is shut off rather than toa high production potential. (C) 2000 Editions scientifiques et medicales Elsevier SAS.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 06/07/20 alle ore 08:09:30