Effects of Stubble Height and Mulching on Wind Erosion in Maize–Peanut Intercropping Farmland

To clarify the effectiveness of different stubble heights and mulching patterns for wind erosion control in maize–peanut intercropping systems, this study was conducted in the black soil region of Northeast China using a combination of wind tunnel simulation and field wind erosion monitoring. Monocropped peanut bare land was used as the control (CK). Four wind tunnel treatments were established: maize stubble with mulching (WT-1), maize stubble without mulching (WT-2), and peanut strip with maize straw mulching (WT-3). Additionally, seven field treatments were established, comprising mulched and non-mulched plots at three stubble height levels (low, medium, and high), as well as a mulched peanut plot without stubble (T7). Wind erosion intensity and amount were systematically measured across all treatments. The results showed that: (1) Wind erosion intensity increased exponentially with wind speed (R2 = 0.90–0.96, p < 0.001). Over the full range of wind speeds, wind erosion intensity was consistently greater in CK and WT-2 than in WT-3 and WT-1. The three mulching treatments exhibited distinct protective characteristics across different wind speed intervals: rapid response of surface mulching at low wind speeds, enhanced wind erosion control of standing stubble at moderate wind speeds, and diminished stubble protection but sustained mulching advantage at high wind speeds. The WT-1 treatment maintained an anti-wind erosion efficiency of 70.15% even at the extreme wind speed of 18 m·s−1. (2) Field wind erosion amounts ranked as CK > T6 > T2 > T4 > T1 > T7 > T5 > T3. The medium stubble with mulching treatment (T3) showed a net dust deposition effect with a wind erosion amount of −0.35 g, demonstrating the optimal erosion reduction performance. (3) Standing stubble and surface mulching synergistically increased aerodynamic roughness by 22.86–394.44%, effectively reducing near-surface wind speed by 30.32–55.55%. Meanwhile, straw mulching reduced soil water evaporation, increased pre-sowing surface soil water content by 5.4–126.01%, and enhanced inter-particle cohesion, thereby effectively suppressing soil wind erosion. Therefore, after harvest in the maize–peanut intercropping system in the black soil region of Northeast China, the combined application of maize straw mulching on peanut strips (T7) and medium stubble (40–50 cm) with mulching on maize strips (T3) is recommended as an optimal technical strategy for wind erosion control in the study area and similar brown soil-dominated wind erosion-sensitive regions after autumn harvest.