Sand as shown in the table is the largest of the three soil particles. It shows a greater range in size than either silt or clay (from very coarse to very fine). Sand has a small surface area relative to its weight, low water - holding capacity, and poor plant nutrient retention. The large size of sand particles creates large spaces between particles. Since sand particles do not stick together, they do not compact. Trying to compact a sand soil (one containing 70% or more sand) would be like trying to compact a basket of ping - pong balls. This is one reason why sand - based root zones are commonly used on athletic fields and golf greens. Silt particles are smaller than sand particles, so the space between particles is smaller, providing greater water holding capacity than sand. Silts have low to medium nutrient capacity, and they will stick together rather well because of a clayey surface coating. The properties of silt are intermediate between those of sand and clay. Clay particles are the smallest of the three particles. Individual particles of clay will stay suspended in water and are not visible to the naked eye. Of the three particle types, they have the greatest surface area relative to their weight and the greatest nutrient - holding capacity. Since the space between clay particles is very small and their surface area is large, clays retain water strongly. Clay particles will stick together readily, so clay soils are very prone to compaction.
Clays are categorized into two major groups.
Montmorillonite Clays (found in the Midwest and West) show considerable swelling and shrinking when wet and dried, respectively, and have excellent nutrient - retention properties.
Kaolinite Clays (found mostly in the East and Southeast) exhibit little swelling or shrinking and tend to have poor nutrient - holding properties.
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