A culture support substrate comprising: a first part, making up the backbone of the substrate and representing more than 70% of the total volume of the substrate, composed of particles P>;100 μm with particle size greater than 100 μm, the particles as a whole consisting of hard particles PH>;100 and/or of resilient particles PR>;100, wherein the resilient particles make up a proportion by volume PV of between 0% and 100% by volume of this first part; a second part of corpuscular components P<;100 with a particle size of less than 100 μm, and making up from 0 to 450 g/l of the substrate; a third part, making up from 0 to 200 g/l of the substrate, composed of fine fibers between 3 mm and 100 mm in length and between 5 μm and 35 μm in diameter; and a fourth part, making up from 0 to 200 g/l of the substrate.