Silicon cycles soils

When the concentration of relatively insoluble elements in soil solutions reaches saturation with secondary minerals, they precipitate in soils, particularly tropical soils. Lucas (2001) points out that precipitation of silicon, aluminum, and iron in tropical soils occurs because of the low solubility of clay minerals and oxides and the high concentrations of these elements in the topsoil horizons produced by plant cycling of these elements. 

The characteristics of the soil from muddy farmland are very different from rocky moimtainous terrain. The angle of the cleat, which forms part of the grip pattern, can help grip the soil material whilst releasing it when the foot is lifted off at the end of the walking or t cycle. Materials within the cleat may also assist in the release of soil fiom its sidewall. The use of silicone as part of the cleat sidewall, which does not directly involve friction grip onto an object surface, has been considered to help the release of soil materials. 

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