TEMPERATURE OF SUBSTRATES IN RELATION TO TROUGH CHARACTERISTICS

In cold greenhouses under Mediterranean conditions the changes in air and soil temperature are very important; at the rhizosphere level these changes could be greater in soilless cultivation.

Regarding the effects of temperature on root activity a study was carried out aimed at quantifying, in the summer and winter seasons, the thermal levels of organic (coconut fibre) and mineral (expanded clay) substrate in relation to trough material (polystyrene and polypropylene), shape (rectangular and square sections) and size (40 l/ml and 90 l/ml). The data were also recorded in a sandy soil.

Recorded temperatures confirmed, over the studied factors, the highest daily variations in the substrate compared to those in the soil (about 10°C greater). Moreover significant differences occurred in relation to the substrate and to the shape and size of the trough.
The extreme values of temperature were 40.7 and 4.9°C in the mineral substrate and 35.1 and 6.7°C in the organic one.
The greatest volume of substrate attenuated maximum temperature in the summer and minimum temperature in the winter of about 4.5°C and 3°C respectively.
Both extreme temperatures were about 2°C lower in the square shape.

V International Symposium on Protected Cultivation in Mild Winter Climates: Current Trends for Suistainable Technologies

F. Giuffrida

rhizosphere temperature, container

https://doi.org/10.17660/ActaHortic.2001.559.95