Chemical Composition of Plant Residues Regulates Soil Organic Carbon Turnover in Typical Soils with Contrasting Textures in Northeast China Plain

Soil organic carbon (SOC) turnover plays a pivotal role in achieving C neutrality, promoting retention and increasing soil fertility. Residue biochemistry texture essentially determine SOC distribution (including CO2 mineralization stock soil) farmland. However, less is known about allocation of residue-C with contrasting the fate under two different textures. This study was conducted 61-day aerobic incubation Black soils distinct (clay loam vs. sandy loam) Northeast China. Chemical composition seven residue parts (soybean roots, leaves, stems maize leaves top bottom stem parts) characterized using solid-state 13C nuclear magnetic resonance spectroscopy. The results showed that both crops contained significantly higher nitrogen (N), carbonyl aryl concentrations lower (C) lignin than other parts, resulted faster decomposition soils, especially clay loam. Stems O-alkyl di-O-alkyl concentrations, C/N lignin/N, while roots aromaticity. Maize larger slow pool longer half-life had contribution to accumulation parts. textures also induced great impact on turnover. favored sequestration due Generally, alkyl/O-alkyl ratio most significant correlation SOC, emission biochemical factors loam; whereas loam, lignin/N indicator for accumulation. provides insights into differences chemical among various highlights effects