Development of planting substrates for ecological restoration using quarry waste

Area of Science:

• Environmental Science
• Soil Science
• Waste Management

Background:

• Quarry waste presents disposal challenges and contributes to land resource scarcity.
• Externally sourced soil is often used for landfill cover and slope restoration, increasing costs and environmental impact.

Purpose of the Study:

• To develop a novel artificial planting substrate (APS) using quarry waste.
• To optimize APS composition for improved physicochemical properties and plant growth.
• To provide a sustainable solution for quarry waste utilization and ecological restoration.

Main Methods:

• Orthogonal experimental design with four factors (polyacrylamide, weathered basalt, mudstone, straw powder) and four levels.
• Glutenite was used as the base matrix for APS development.
• Evaluation of APS physicochemical properties and plant growth under varying component ratios.

Main Results:

• Pure glutenite was unsuitable as a planting substrate.
• Polyacrylamide (PAM) at 0.3% optimized water-holding capacity, nitrogen content, and plant growth.
• Weathered basalt (60%) improved phosphorus content and cation exchange capacity.
• Straw powder enhanced porosity, moisture, organic carbon, and available nutrients, while reducing pH.
• Optimal APS formulation: 0.3% PAM, 60% weathered basalt, 40% mudstone, 6% straw powder (ratios to glutenite).

Conclusions:

• The developed APS effectively utilizes quarry waste for ecological restoration.
• Optimized APS composition significantly improves substrate properties and promotes plant growth.
• This research offers a theoretical and technical foundation for quarry area ecological restoration and waste resource utilization.