Clay between silts and clays based on the plasticity properties of the soil, as measured by the soils' Atterberg limits. ISO 14688 grades clay particles as being smaller than 2 μm and silt particles as being larger. Mixtures of sand, silt and less than 40% clay are called loam. Loam makes good soil and is used as a building material. Clay minerals typically form over long periods of time as a result of the gradual chemical weathering of rocks, usually silicate-bearing, by low concentrations of carbonic acid and other diluted solvents. These solvents, usually acidic, migrate through the weathering rock after
Sand-based athletic fields a major concern when managing a sand-based turf system. Nutrient leaching occurs more readily in a sand-based system because sand has a relatively low cation exchange capacity (CEC). This refers to the sand's ability to retain nutrient particles. Soil particle "hold on" to positively charged nutrient particles because they are negatively charged. The opposite charges cause the nutrients to adhere to soil particles which can then be taken up by plants. Sand has virtually no CEC, whereas clay and organic matter have relatively high CEC. This means that the higher the clay and organic matter of a soil, the more