http://www.cnr.it/ontology/cnr/individuo/prodotto/ID174870
Automated closed-system canopy-chamber for continuous field-crop monitoring of CO2 and H2O fluxes. (Articolo in rivista)
- Type
- Label
- Automated closed-system canopy-chamber for continuous field-crop monitoring of CO2 and H2O fluxes. (Articolo in rivista) (literal)
- Anno
- 2002-01-01T00:00:00+01:00 (literal)
- Alternative label
- Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#autori
- Steduto P.; Çetinkökü Ö.; Albrizio R.; Kanber R. (literal)
- Pagina inizio
- Pagina fine
- Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroVolume
- Rivista
- Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#affiliazioni
- CIHEAM-IAMB;
Çukurova University, Adana, Turkey (literal)
- Titolo
- Automated closed-system canopy-chamber for continuous field-crop monitoring of CO2 and H2O fluxes. (literal)
- Abstract
- As compared to steady-state open-system, transient-state closed-system canopy chambers for gas-exchange determinations of field crops have the advantages of relatively lower cost, simpler operational requirements and reduced disturbance of plant environment. Portability is an additional and essential characteristic of the transient-type canopy chambers, achieved by \"carriers\" such as farm tractors, fork-lifts, gantries or simply men, in order to re-locate the chamber from place to place in the field. The presence of man, though, is required in all cases and thus imposes strong limitations on the day and night monitoring of the gas-exchange determinations.
To overcome these limitations, an automated closed-system chamber was developed to allow unattended day and night, high frequency CO2 and H2O exchange measurements. The automated chamber is illustrated in terms of design, technical solution and operation.
Environment tests on the chamber performance indicated that: leaks introduced maximum errors of 1% in the flux calculation; turbulence effect on CO2 and H2O fluxes was not detectable; during the measurement period, temperature build up inside the chamber was typically within 1-2 °C range; photosynthetic photon flux density (PPFD) attenuation by the chamber as a whole was in the 15-20% range; net radiation (Rn) inside the chamber, instead, was always higher than outside by 10-20%.
Due to the short measurement time (15 s) and the high scanning rate of sampling during measurements (½ s), no differences in flux calculations came out when the rate of change in CO2 and H2O concentrations was derived either by linear or quadratic regressions.
The flux determinations of the automated canopy chamber were compared with other methods. Daily evapotranspiration (ET) of artichoke obtained by canopy chamber was at the most 4.2% lower than ET obtained by high-precision weighing lysimeter. Diurnal ET and carbon exchange rates (CER) of sugarbeet and marjoram crops obtained by canopy chamber closely followed the pattern of those obtained by the Bowen-ratio/energy-balance method, with maximum daily deviations of 6-8 % and 5-6% for ET and CER, respectively.
The results of all tests and comparisons showed that the automated chamber presented is a valuable and accurate tool for monitoring day and night CO2 and H2O fluxes. (literal)
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- Autore CNR
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