Dataset of soil organic carbon fractions, aggregate stability, and chemical structure across topographical gradients under furrow corn straw mulch

This dataset contains the raw experimental data from an 11-year long-term field experiment conducted in the Chinese Chernozem region. The study evaluated the spatial redistribution and coupling mechanisms of soil organic carbon (SOC) physical protection and chemical stability on sloping farmlands. The data includes soil aggregate size fractions, soil organic carbon (SOC), dissolved organic carbon (DOC), humic substances (HA, FA, HM), and molecular structure parameters derived from solid-state ¹³C NMR spectroscopy. Samples were collected from three slope gradients (3°, 6°, 9°) and three slope positions (Upper, Middle, Lower) under two treatments: bare control without straw (CK) and furrow corn straw mulch (SR).