Water-stable aggregates and aggregate-associated organic carbon after two years of biochar application

Abstract

ABSTRACT Solving the soil organic carbon (SOC) sequestration problem is crucial for agricultural sustainability. The main objective of our study was to assess the effects of biochar derived from different organic wastes on SOC, SOC storage, and soil aggregate fractions in a corn-Chinese cabbage rotation system. A consecutive two-year field experiment was conducted with six fertilization treatments, including nonfertilization (CK), mineral N, P, and K fertilizer (NPK), distiller-derived biochar (NPK + D), tobacco-derived biochar (NPK + T), tobacco-derived modified biochar (NPK + TM), and corn straw-derived biochar (NPK + CS). Compared to the NPK treatment, the NPK + D, NPK + T, and NPK + TM treatments significantly increased SOC by 56.3%, 58.6%, and 31.7%, respectively. Among all treatments, the NPK + T treatment had the highest SOC storage at 32.1 t ha−1. Compared with CK, the NPK + T treatment increased large macroaggregates and small macroaggregates by 38.3% and 10.7%, respectively. Compared to the NPK treatment, the biochar treatments improved the geometric mean diameter (GMD) by 15.5%–25.2%. Biochar has considerable potential for enhancing crop productivity in degraded yellow soils by improving the physical environment.