Wheat Straw Incorporation Affecting Soil Carbon and Nitrogen Fractions in Chinese Paddy Soil

Soil organic carbon (SOC) and nitrogen (N) fractions greatly affect soil health quality. This study explored the effects of wheat straw incorporation on Chinese rice paddy fields with four treatments: (1) a control (CK), (2) mineral NPK fertilizer (NPK), (3) moderate (3 t ha?1) plus (MSNPK), (4) high (6 (HSNPK). In total, 0–5, 5–10, 10–20, 20–30 cm depths were sampled from in China. Compared CK, HSNPK treatment (p < 0.05) increased C fraction content (from 13.91 to 53.78%), mainly including SOC, microbial biomass (MBC), water-soluble (WSOC), labile (LOC) profile (0–30 cm), it also N 10.70 55.31%) such as total (TN) at 0–10 depth, (MBN) 0–20 (WSTN) 0–5 depths, (LTN) 0–30 depth. The primary components LOC LTN are MBC MBN. Various positively correlated each other 0.05). promoted MBC, WSOC, SOC ratios, MBN, WSTN, TN ratios depth cm. To summarize, application could maintain improve quality, which leads grain yields.