Agroforestry management improves soil surface layer structure and hydrological behavior

Abstract

Long-term inappropriate agricultural and forestry practices can degrade soil structure, compromising critical hydrological functions such as water regulation, groundwater recharge, and storing and filtering of water. This study assessed the hydro-physical attributes of soils under different land uses, aiming to identify their impacts and relationships using Principal Component Analysis (PCA). We hypothesized that agroforestry systems (AF) would improve soil structure compared to crop (CR) and forest monocultures (EP). Our findings confirmed improvements in soil structure within the surface layer (0–10 cm) under AF, evidenced by very high infiltration rates (515.5 mm.h⁻¹) compared to CR (93.0 mm.h⁻¹) and EP (154.9 mm.h⁻¹). AF also showed higher total porosity (0.51 m.m⁻³), better aggregate stability, and higher soil organic carbon (SOC), promoting better hydrological functioning. In contrast, CR exhibited higher bulk density (BD) (1.41 g.cm⁻¹), lower mean weight diameter (MWD) (1.27 mm), and reduced SOC (12.62 g.kg⁻¹), indicating greater erosion susceptibility due to compromised aggregation and infiltration. EP soils showed signs of compaction, with increased BD (1.46 g.cm⁻¹), MWD (2.48 mm), and penetration resistance (PR) (2.01 MPa). PCA analysis revealed that land use impacts are more pronounced in surface layers, while subsurface layers are influenced mainly by pedogenetic processes. These results highlight the importance of adopting sustainable practices, such as agroforestry, which minimize soil disturbance and enhance organic matter inputs to maintain soil health and hydrological functioning.