Comprehensive analysis of compost maturity differences across stages and materials with statistical models.

Abstract

Aerobic composting is an environmentally friendly and effective approach to treating organic solid waste. The variability in material composition introduces complex interactions between environmental factors and materials, which in turn affects compost maturity. This study uses multiple statistical analyses to systematically compare key indicators across composting processes for kitchen waste, livestock manure, and sludge. The results show that material type and composting stage have a significant impact on compost maturity (p < 0.001). High-precision modeling (R² > 0.90) was achieved using a Stacking model on the composting dataset, with interpretability analysis highlighting the important roles of temperature, moisture content, and nitrogen content across different composting materials. The combined effects of environmental and material changes jointly influence the composting progression. In kitchen waste composting, strong interactions between multiple indicators were observed, while moisture shifts in livestock manure and sludge composting primarily influenced compost maturity by promoting decomposition and enhancing nitrogen retention, respectively. Partial dependence analysis quantified the relationships between key indicators and compost maturity scores. These findings offer a scientific basis for identifying key factors and optimization paths in various composting processes, supporting the development of more effective composting strategies.