The medium layer is made of green artificial soil (see Figure 5), because it has good air permeability and water retention, and can maintain the looseness of the soil
The media layer is made of green-preserving artificial soil (Figure 5) because of its breathability, good water retention, and the ability to maintain soil looseness
Green keeping artificial soil (as shown in Figure 5) is selected as the medium layer, because it has good air permeability and water retention, and can maintain the soil porosity<br>