This article examines the role of soil minerals as diagnostic indicators for assessing land degradation in Ultisol and Inceptisol soils subjected to intensive horticultural cultivation in the upstream area of the Jeneberang Watershed, South Sulawesi. The study analyzes changes in mineralogical composition, particularly primary and secondary minerals, as affected by long-term horticultural practices such as continuous tillage, fertilizer application, and crop rotation. By comparing degraded and non-degraded soil profiles, the research identifies key mineral transformations, including the depletion of weatherable minerals and accumulation of clay minerals like kaolinite and iron oxides, which correlate with declining soil fertility, structure, and water-holding capacity.Results indicate that Ultisols show more advanced mineral weathering and higher susceptibility to degradation than Inceptisols under similar management. Specific mineral indices are proposed as early warning indicators of degradation, offering a practical tool for land evaluation and sustainable management planning in tropical upland horticultural systems.The findings provide a scientific basis for developing conservation strategies to mitigate land degradation and maintain soil productivity in the Jeneberang Watershed.

Research on the impact of climate change on soil susceptibility in the Tangnga watershed, Bantaeng, South Sulawesi, Indonesia

Land susceptibility research in the Kelara River Watershed and Sub-watershed in Rumbia District, Jeneponto Regency, was conducted in 2021.

Rainfall with C-2 type of climate in areas with carbonate rock as a parent material has influenced the recrystallization process of calcite minerals in the rock body and contributed free nutrients to the soil. This process forms a lot of halloysite, vermiculite, and nontronite minerals. The process of inundation twice a year also enhances the hydropedological process and speeds up the process of oxide mineral formation in the soil. Land use for over 70 years has been able to form a pan oxide layer with the main minerals e.g. ferrihydrite, hematite, and goethite. The presence of oxides mineral in the soil gives a high color value and croma. The soils formed are classified as Aquic Durudepts category. This soil has low c-organic content, high bulk density, and base saturation in the medium category. The rainfall has a positive correlation with soil water content and CEC. But has a negative correlation with soil pH and base saturation.
Rainfall with D-2 type of climate in areas with carbonate parent rock gives only small contribution to hydropedological process but high in the accumulation of nutrients in soil. The soil has a high base saturation and pH value is close to neutral. This condition forms a lot of montmorillonite and nontronite minerals in the soil. The inundation process once a year forms oxide minerals, such as ferrihydrite and lepidocrocite mineral. The soil formed is classified as Udic Haplusterts category, with characteristics such as; high c-organic content, provided soil color with low value and croma, and high percentage of base saturation. The relationship of soil parameters showed a positive correlation between c-organic with base saturation, but has a negative correlation between water content and soil bulk density.

The soils susceptibility were very closely related to the layers which have the liquid limit 174 range from 60% to 72% and have plasticity index on ≤20%clay, with the minerals contain were 175 kaolinite and halloysite as 1:1 type and vermiculite as 2:1 type.