Diversified Cropping Systems Improve Soil Quality and Infiltration Characteristics in the Tropical Northern Guinea Savanna

Soil degradation continues to threaten arable lands across the Northern Guinea Savanna (NGS), undermining soil quality and food production and necessitating sustainable management strategies. This study aimed to identify cropping systems that improve soil physical, chemical, and infiltration properties in the NGS. Soil samples were collected under four established cropping systems—Agroforestry (AGF), Intercropping (INT), Crop Rotation (CRT), and Monocropping (MNC)—at the topsoil layer (0–20 cm). Field infiltration was measured using the Turftec infiltrometer, and the Philip and Kostiakov models were evaluated. The soil textural class under AGF was sandy loam, whereas INT, CRT, and MNC were classified as loam. Bulk density was highest under AGF, attributable to textural differences. Aggregate stability was 9.0%, 23.2%, and 13.3% higher under AGF compared to CTR, INT, and MNC, respectively. Saturated hydraulic conductivity was higher under the diversified cropping systems, ranging from 50.29 to 67.21 cm h−1, compared with MNC (23.99 cm h−1). Soil organic carbon increased by 22.95–72.29%, while exchangeable Ca increased by 26.82–84.14% under CRT and AGF, respectively, compared with MNC. Available P was highest under AGF and lowest under INT. Aggregate stability and cumulative infiltration increased in the following order: AGF > CRT > MNC > INT. The Kostiakov model had a higher R2 (0.95–0.99), lower MAE (0.337–0.837), and lower RMSE (0.5–1.4) than the Philip model, suggesting higher applicability for the NGS. The results highlight the potential of diversified cropping systems, especially agroforestry and crop rotation, as sustainable management strategies to improve soil quality and enhance agricultural resilience in the NGS.