Silt will form clods that crumble easily when wet. Water soaks readily into silty soil, and such soil holds its moisture well. The coarser silt particles are similar to the finer sands in particle surface exposed and therefore take very little part in the chemical activities of soils. The finer silt has sufficient particle surface area to give it some chemical activity. The particles stick together and form clods that are difficult to break when dry.
Clay soils have a much larger surface area per weight due to their small size.
The amount of clay in the soil has a great influence on its total water-holding capacity. In addition, certain available nutrients are held on the surface of the clay particles. Therefore, clay acts as the major storage reservoir for both water and nutrients. Using a soil texture triangle, have the students apply the following information to soil samples. The soil triangle shows how the various separates combine to form the various classes of soils.