Which feature indicates the presence of certain minerals in soil?

The presence of certain minerals in soil can often be indicated by the existence of iron or manganese nodules. These nodules form as a result of the weathering processes that concentrate specific minerals and elements within the soil profile. Iron and manganese oxides can precipitate out of solution and form visible nodules, which are commonly associated with certain soil types and environmental conditions. Their presence typically signals more about the soil's mineral composition and can provide insights into the nutrient availability for plants, as well as the soil's drainage and aeration characteristics.

In contrast, high moisture levels do not necessarily indicate specific minerals but rather reflect the soil's water-holding capacity. A granular soil structure suggests good aeration and drainage but does not directly point to specific minerals. Increased organic matter enriches the soil with nutrients but is more associated with the biological aspect of soil rather than its mineral content.