ISHS Acta Horticulturae 396: Hydroponics and Transplant Production
PHYSICAL, CHEMICAL AND BIOLOGICAL PROPERTIES OF GROWING MEDIUM |
| Author: | F. Lemaire |
| Keywords: | Soilless culture, Substrate, Physical properties, Chemical properties, Biostability, Receptiveness |
| DOI: | 10.17660/ActaHortic.1995.396.33 |
| Abstract:
In soilless culture, the substrate is an important factor to obtain the best growth of ornamental and vegetable plants. Many kinds of materials can be used ; mineral and organic but, whatever the substrate nature is, it is necessary to know its characteristics. As physical properties, the total porosity, the water and air capacity at 1 kPa (pF1) and 10 kPa suction (pF2), the available water are taken into account. All known materials can be ranked into four classes. Consequences for irrigation are also drawn from those characteristics. The chemical properties are the following : pH H20, Cation Exchange Capacity (CEC), electrical conductivity (EC), P fixing capacity and nutrient potential. Investigated materials can be divided into two classes : without or with CEC. To calculate the fertilization before planting and to control the salinity level during the growing, those characteristics are used. The biological characteristics are considered according to two points of view : consequences of the C/N ratio for the biostability of organic materials ; the substrate availability to welcome and to keep phytopathogen or beneficial microorganisms (fungi, bacteriae). The choice of the substrate must be realized according to the nutrient supplying technique (solution, long term fertilizer), the watering technique (sprinkling, dripping, sub-irrigation) and also the level of the grower technicality. | |
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