RECENT TRENDS IN PROTECTED CULTIVATIONS-MICROCLIMATE STUDIES: A REVIEW

New constraints’ for agricultural production also apply to protected cultivations’. A sustainable production of fruits, vegetables and ornamentals is now requested, with lower environmental impacts, particularly less energy, pesticides and mineral pollution and better production’s quality. Exploring or revisiting the new climate-crop relationships induced by these novel production constraints is required.
A high quality production of vegetables and ornamentals under cover with less energy, water, fertilizers and pesticides call for a precise comprehension of the climatic determinism of (i) plant functioning but also of (ii) the interactions between the aerial and root zones of the plants and (iii) the climatic interactions between the various biotic agents living in the greenhouse (crops, bio-aggressors and bio-control agents).
In view of these approaches, substantial advances have been observed with respect to the exploration of the distributed greenhouse climate but also plant activity using both wireless sensors and geostatistical methods. They are completed by also substantial progresses in Computer Fluid Dynamics (CFD) assisted characterization of the phenomena occurring in greenhouses.
The studies about the crop-climate relationships induced by the new energy saving techniques are first reviewed. They indicated that the consequences of high inside air confinement, as in closed or semi closed greenhouses, on inside air humidity and CO2 content are very important and their consequences are analyzed in terms of crop photosynthesis and transpiration. Also, crop-climate relationships are reviewed for the new simple protected cultivation systems, such as the screenhouses, which develop rapidly in tropical and inter-tropical regions.
The interactions between the aerial climate and the root zone are also evaluated with respect to the requested minimization of water and nitrogen’s leakages for both soilless and in-soil cultivations.
More generally, the climatic dependences of other organisms than cropped plants present in the shelters, such as bio-aggressors and bio-control agents which can help saving pesticides, have been reviewed.