What are the requirements for the use of soil in the cultivation of orchids?

Soil: the native land of Magnolia is under the trees of high-altitude forests in southern Africa, and its roots are rooted in decaying leaves that have been accumulated for many years. The gentleman orchid should use loose and fertile neutral or weakly acidic humus soil, and the cultivation soil can be mixed with 65% humus soil, 20% net sand and 15% fine furnace ash. The relative humidity of the soil should be about 40%.