A chemical and clay mineralogical study of a yellow-grey earth profile from the Wairarapa

Abstract

Essentially, a soil is a natural body that supports plants. It possesses properties due to the integrated effect of climate and living organisms acting upon parent material and conditioned by relief, over periods of time. Thus no soil is a static body for as the environment is ever changing, the soil must change to remain in equilibrium with it. In a sense, the soil is in constant evolution. Soils generally are composed of rocks and minerals (fragmented and in various stages of weathering), also organic matter, water and air in various proportions. They are differentiated into layers termed horizons. A soil profile is a vertical section from the surface to parent materials. A hypothetical soil profil is show in diagramatic form below, (fig.1).