Active carbon fractions mediate microbial responses to long-term organic–inorganic fertilization and full-film mulching in a Loess Plateau wheat system
This six-year study on the Loess Plateau demonstrates that combined organic–inorganic fertilization with full-film mulching significantly boosts grain yield and soil biological function by increasing active carbon fractions, which serve as the primary drivers of microbial abundance and enzyme activity rather than total soil organic carbon.