Year: 2025
Type: article
Abstract: Objective The genesis and evolution of lateritic soils in tropical monsoon regions differ markedly from those in other climatic zones，primarily due to prolonged high-temperature and high-rainfall conditions.However，the influence of parent material on soil aggregation and stability in these regions remains insufficiently understood.Using Hainan Province，China，as a case study，this research focuses on lateritic soils developed from basalt and granite，two dominant parent materials in the region，to explore how parent material regulates aggregate composition and water stability.The aim is to provide a scientific basis for optimizing soil structure and enhancing sustainable land management in tropical monsoon climates. Method Two representative lateritic soil types were selected in Hainan Province：basalt-derived soils from Meilan District and granite-derived soils from Danzhou City.Stratified sampling was performed for each profile，collecting A and B horizon soils（0-10 cm，30-40 cm for basalt；0-15 cm，>15-45 cm，>45 cm for granite）.Soil aggregates were separated by dry sieving into four size classes（10->5 mm，5->2 mm，1->0.5 mm，0.25->0.1 mm）.Aggregate water stability was assessed using the fast wetting method proposed by Le Bissonnais.Three quantitative indices were used：normalized mean weight diameter（NMWD），Percentage of macroaggregates index（PMI），and Anti-Slaking Index（ASI）.Soil physicochemical properties（pH，bulk density，organic carbon，sesquioxides，texture，CEC）were also measured.Redundancy analysis（RDA），Mantel tests，and structural equation modeling （SEM） were applied to explore multivariate relationships among soil properties，aggregate fractions，and stability indices. Result Aggregate size distributions exhibited distinct bimodal or unimodal patterns，with peaks generally shifting toward finer fractions（0.5->0.25 mm and 0.25->0.1 mm）after wet sieving.Basalt-derived soils demonstrated significantly greater aggregate stability compared to granite-derived soils，particularly in the surface（A）horizons，reflecting enhanced erosion resistance due to higher organic matter content and sesquioxide accumulation.Aggregates in the 0.25->0.1 mm size class exhibited the highest stability across all profiles（NMWD>0.66，ASI>57%），attributed to their dense internal structure and cohesive bonding.In contrast，larger aggregates（>2 mm）contributed more substantially to improving bulk soil water stability，as evidenced by strong positive correlations with water-stable aggregate content（WSA），MWDwet，and GMDwet（|R|>0.7）. Conclusion This study demonstrates that parent material plays a decisive role in determining aggregate size distribution and stability in tropical lateritic soils.Basalt-derived soils exhibit superior physical structure due to favorable mineral composition，higher clay and sesquioxide content，and higher organic matter accumulation.These characteristics promote the formation and stabilization of both micro- and macroaggregates，enhancing erosion resistance and soil quality.Conversely，granite-derived soils，with limited weatherable minerals and lower fine particle content，are more vulnerable to structural breakdown under moisture fluctuations.The dual role of fine aggregates（for internal stability）and large macroaggregates（for structural preservation）is essential for maintaining soil function.These findings provide important theoretical support for soil conservation and land-use planning in tropical monsoon regions.In practice，management strategies such as organic matter addition，reduced tillage，and selection of cultivation zones based on parent material should be emphasized to promote soil resilience and long-term sustainability.
DOI: 10.3724/aauj.2025146
Authors: Xin CHEN, Junkang XU, Chongfa CAI, Jie WANG
Language: English
Subfield: Soil Science
Domain: Life Sciences
SDG: Life on land
Open Access status: bronze
Award: G1402372987
OpenAlex ID: W7125658273
FWCI:
Cites:
Cited by:
Related to: