Irrigation in soilless culture is generally managed by taking into account the air-filled porosity and water availability of the growing medium for plants, which are determined before culture from the water retention curve. However, many factors can affect the physical properties during the growth period and then lead to poor irrigation. This study aimed to analyze the combined effects of root development and irrigation management on the hydraulic properties of organic media and their consequences for water and air availability for the root system with time. A culture of Radrazz Rosa ×hybrida was performed with four different materials (peat, pine bark, coir, and wood fiber) during 6 mo in a greenhouse, with the most common irrigation management between −1 and −10 kPa. Root volume, total volume, air and water retention properties, saturated hydraulic conductivity, relative gas diffusivity, and wettability of each growing medium were measured at the beginning and the end of the experiment. The study showed different physical behaviors for the growing media in terms of air and water retention but mainly highlighted decreases in total volume, pore tortuosity, and wettability and an increase in gas diffusion as the common and most relevant parameters influencing their evolution with time.

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