Which of the following is NOT a factor indicating soil texture?

Soil texture refers to the relative proportions of different particle sizes present in the soil, specifically sand, silt, and clay. These elements directly impact soil characteristics such as aeration, drainage, and nutrient retention.

The measurement of minerals is not a direct indicator of soil texture, as it focuses more on the chemical composition and nutrient content of the soil rather than its physical structure. The other factors, like the proportion of sand and the amount of clay, clearly define the grain size distribution which is central to understanding soil texture. Additionally, the water drainage rate can also be influenced by soil texture, as different textures drain water at different rates. Therefore, the identification of minerals does not pertain to the categorization of soil texture in the same way that the other factors do.