What Three Types of Sediment Are Measured to Obtain Soil Texture?

• Soil texture is an important part of successful gardening. Alistair Berg/Digital Vision/Getty Images

  Soil is made up of different sized inorganic sediments. The combination of these particles is referred to as soil texture, which is named for the percentage of sand, silt and clay found in the soil. A 90 percent mixture of sand is called sandy soil. Clay soil is a mixture with at least 50 percent clay. Loam is the best mixture for plants with equal parts of sand, silt and clay. The soil texture is important since it determines how much moisture the soil holds, how fast the soil drains and what nutrients are in the soil.

Sand

• Sand is the coarsest inorganic particle in the composition of soil texture. It is usually visible to the naked eye. The grains show up clearly with a magnifying glass. Sand feels gritty when rubbed between the fingers. Sand has the fastest drainage of the three types of sediments. It also does not hold moisture or contain many nutrients. Sand keeps plant roots dry, so plants that tend to like arid conditions do well in sandy soils.

Silt

• Silt is medium sized inorganic particles that you cannot see without the aid of a microscope. This particle type feels smooth and floury to the touch when dry. When silt is pressed down with fingers, it will retain its shape. Silty soil drains and stays moist without being overly wet. Silt is full of nutrients, which makes silt ideal for growing plants.

Clay

• Clay is the finest of all the inorganic particles in soil. The individual particles are only seen with the aid of an electron microscope. Clay is smooth to the touch when dry, but slick and sticky when wet. Wet clay keeps its shape when molded. This causes soil with high clay content to compact. Clay soil's surface becomes hard and cracked when it dries out. Clay drains slowly, so it stays wet for long periods of time. This tendency to stay wet lowers the oxygen content of clay soil, which retards the growth of plant roots. Plants adapted to survive long periods of soggy soil do well in clay soil.