Soil mechanics not moving, the water pressure obeys the equation of hydrostatic equilibrium, formula_89, but note that formula_93, is negative above the water table. Hence, hydrostatic water pressures are negative above the water table. The thickness of the zone of capillary saturation depends on the pore size, but typically, the heights vary between a centimeter or so for coarse sand to tens of meters for a silt or clay. In fact the pore space of soil is a uniform fractal e.g. a set of uniformly distributed D-dimensional fractals of average linear size L. For the clay soil it has been found that
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