sand, description of sediment or soil which is made up of relatively large particles (bigger than silt, and much bigger than clay). See soil texture and geology for more details of this particular form of soil classification. Sandy soils can be difficult to cultivate because of their poor ability to store water and nutrients, but they are notable in viticulture for providing a good measure of protection from the phylloxera louse. Vineyards dominated by sand include those of colares in Portugal, the Camargue in the south of France, the Great Plain of hungary, and Maipo Valley in chile.
