The substrate manufacturer Grupo Projar has recorded a 30% growth of its water retention analysis service, designed to facilitate the choice of the most suitable substrate for the growth of ornamental plants and horticultural and fruit products. This growth entails a technification that contributes to the sector and to the good development of horticultural products.
This analysis determines the relation between water and air and the variations in the amount of water retained by the substrate under several tensions. Samples are taken from the substrate, which are then saturated with water and subjected to various pre-set tensions. After the time has passed, the distribution of solid material (substrate), water and air is measured.
The objective of this analysis is to learn how a substrate behaves hydrically. Until now, the sector worked on the basis of the chemical composition of the substrate, but it was not easy or quick to carry out physical analyses of the substrate.
Water behaviour
Thus, this technique provides essential information for the choice of a suitable substrate, such as aeration capacity, readily available water, back-up water and hardly available water.
The first parameter refers to the volume percentage of substrate containing air after being saturated in water and allowed to drain under 10 cm of water column tension. That is, the equivalent of leaving a 10 cm high substrate to dry freely.
The readily available water is the volume of water retained by the substrate at between 10 and 50 centimetres of water column tension; in other words, the water that the plant can consume practically without any energy expenditure. Meanwhile, reserve water is the one that, in times of difficulty, may be available to the plant, but which entails a superfluous use of energy.
The hardly available water parameter refers to the water retained by the substrate which requires a greater effort on the part of the roots for its absorption, especially in the case of ornamental plants.
Substrate with 20% aeration
In this sense, Projar's Product Manager Álvaro Villalba explains that "based on these studies and analyses, the company has determined how, for example, the Potplant 1040 Extracoarse substrate, made of blonde peat and coarse coco, is ideal for ornamental plants grown in containers from 14 cm which are sensitive to root hypoxia (lack of oxygen)."
Its analysis shows how a substrate with 20% aeration is ideal for plants that are sensitive to root hypoxia. In this way, the substrate facilitates the handling of irrigation and, consequently, allows for greater control over the development of the plants.
Projar's Product Manager highlights how, in addition to water retention analyses, "we carry out controls on some other parameters, such as porosity, bulk density or contraction index to be able to supply the most suitable and ideal substrate."
"For years, we have been working to increase the technification within the sector by providing our knowledge, because we believe that this has a positive impact on everyone's interests, be it nurseries or producers," stresses Alvaro Villalba.
This technique allows us to supply the producer with the substrate he or she really needs based on the specific characteristic of the facilities, the crop variety, the type of pot or the type of irrigation.
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