Bioenergy Potential from Crop Residues: A Systematic Review and Climate-Stratified Meta-Analysis of Residue Generation Factors

The study synthesizes 186 peer-reviewed studies to develop a harmonized, climate-adjusted framework for estimating the potential for agricultural residue generation for bioenergy applications. A systematic literature search across Web of Science and Scopus identified two fundamentally distinct estimation paradigms, dimensionless residue-to-product ratios (RPR) for annual crops and area-based pruning yields (t ha⁻¹) for permanent orchard systems, segregated prior to quantitative pooling to preserve dimensional consistency. Random-effects meta-analysis on log-transformed RPR values generated validated pooled baselines for six major crop systems: wheat straw (1.27), maize stover (1.39), rice straw (1.34), cotton stalks (3.03), sugarcane bagasse (0.28), and cassava stalks (0.37). Permanent crop pruning yields were pooled separately: vineyard (1.56 t ha⁻¹), olive (1.93 t ha⁻¹), and apple (4.34 t ha⁻¹). Subgroup meta-regression identified climate zone as a statistically significant moderator for wheat (p = 0.046), maize (p = 0.004), and rice straw (p = 0.023), revealing a latitudinal RPR gradient across all three cereal systems. The estimation method group was non-significant across all crops, confirming cross-methodological consensus. The repository provides full transparency for all quantitative analyses, including the corrected extraction dataset, Python analysis scripts, processing sub-pool datasets, subgroup regression outputs, and the consolidated Golden Table of climate-stratified sustainable baselines.