| Substrate name | Composition | Characteristics | C sequestration (g C/m2/yr) |
|---|---|---|---|
| Lightweight Nutrient Substrate (LNS) | Local natural soil | Lightweight: Suitable for rooftops with strict load-bearing requirements. Balanced nutrients: Rich in organic matter and slow-release fertilizers, supporting long-term plant growth. Good water retention and aeration: Maintains moisture during dry periods while preventing waterlogging. Wide applicability: Suitable for a variety of plant types, including herbaceous and shrub species. | 8.15 |
| Modified Soil Substrate System (MSSS) | Soil mixture prepared by combining sludge and local soil at a 1:1 volume ratio | Structural stability: Maintains a stable soil structure, supporting root development. Strong amenability: Customizable formulas based on plant species, offer high flexibility. High nutrient retention: Beneficial for long-term plant growth, reducing the need for frequent fertilization. Medium weight: Suitable for rooftops with moderate load-bearing capacity. | 7.03 |
| Waste-Based Modular Substrate (WBMS) | Artificial substrate produced from construction waste | Environmental recycling: Reflects the concept of a circular economy, reducing urban solid waste. Lightweight and high strength: Modular processing ensures both structural strength and lightweight properties. Modular design: Facilitates easy installation and maintenance, enabling quick replacement and mobility. | 12.8 |
