Land use impacts on weathering, soil properties, and carbon storage in wet Andosols, Indonesia

•Land management affect the weathering of minerals.•Decrease of net acidification through agricultural practice.•The change of soil chemical properties under agricultural practice is considered to be an expression of soil phenoforms.•Increase of organic carbon stock after conversion to cultivated land.•Formation of SRO aluminum promotes retention of organic carbon. We investigated changes in geochemical soil properties in response to deposition age and land use management over 30 – 50 years on tropical volcanic soils. Our purpose was to find out how weathering stage and land use interactively affect soil properties and organic carbon, and to check if phenoforms (management-related soil subtypes) exist within the genoforms (genetic soil types). Soil samples were taken at land uses that have been converted (pine forest and agricultural land) and a natural forest as the original land use. The results showed that pine forest soil displayed more intense weathering as indicated by higher values of three weathering indices. Intensive agricultural practices also improved soil chemical properties such as pH, exchangeable base cations, base saturation, and organic carbon stock leading to WRB-qualifier of “eutric” in cultivated soils, whereas the average of bulk density was relatively similar between forests and cultivated soils. Positive correlations were found between amorphous materials and Alo, specific surface area, and micropore volume. Correlations between the content of short-range order Al (hydr-) oxides (indicated by Alo) and organic carbon were found in pine forest and agricultural soils, particularly in subsoils. Our results clearly indicate the increase of base cations retention due to less acidification and an increase of organic carbon stock under agricultural land use, likely due to stabilization with non-crystalline materials.