Forests are being turned into farmland, affecting soil quality. A study compared intact forests with corn fields in tropical acidic red soils. Important indicators of soil quality include organic carbon, nitrogen, potassium, and free iron. Deforestation and corn cultivation led to decreased soil quality. Topsoil was more affected than deeper layers. Loss of total nitrogen and potassium were main factors in soil degradation. Maintaining these nutrients, possibly through fertilization, is crucial for soil quality. Active iron also plays a key role in preserving soil organic carbon levels.