Fill the jar 2/3 with water and add 1 teaspoon of liquid dish detergent or table salt.
Shake the jar thoroughly and let the contents settle.
Measure the depths of the different layers.
Wait one minute to measure the bottom layer of sand.
Wait about 2 hours for the silt to settle and measure it.
Wait several days and measure the clay layer.
Some clay particles will remain suspended.
Soil texture is determined by the relative amounts of sand, silt and clay your soil has. Soil is composed of mineral and organic components. Organic matter can be plant material, manure, decomposing organisms, water, air and living organisms. Minerals are sand, silt and clay. Sand is the largest particle. Silt particles are smaller than fine sand but can still be seen by the human eye. Clay particles are microscopic. The relative proportion of these particles determines the soil texture.
Sandy soil—tends to be very light and dries out swiftly. Water drains very quickly and makes the soil easy to dig. It is the first to warm up in the sun.
Silt soil—retains moisture and feels slippery when wet. Retains nutrients better than sand but does not dry out as quickly.
Clay soil—a very heavy soil, it holds moisture for long periods of time when wet and dries hard as a brick. Clay soil retains nutrients and is very fertile but is heavy, sticky and very hard to dig. It is the last to warm up in the sun.
Loam soil—the ideal soil texture, it is composed of sand, silt and clay. The ideal loam soil contains 40% silt, 20% clay and 40% sand and organic matter. Loam is a separate category because none of its compontents account for more than 50%.
Loam soils are ideal for most plants, although many plants grow well in non-loan soils.
Peat soil—a rare soil type, it could be considered endangered. It is dark in color, heavy, highly moisture retentive, highly acidic, low in nutrients and difficult to work. It is highly prized, but concerned gardeners will no longer use peat as it is disappearing from the planet.
Test Soil Texture by Hand
Take a handfull of moist soil, feel it and rub it between your fingers. If it is rough and gritty and breaks up easily it is sandy. If it feels sticky and like plastic it is clay. If it feels slippery with smaller particles than sand, it is silt. Next try to form a lump with. If it makes a solid lump that won't crumble it is clay. If it won't form a lump but crumbles at once it is sand.
This site is used as a teaching aid for the Web Design & Development course offered by University Technology Training Center (uttc.umn.edu) at the University of Minnesota. It is not intended to be a reliable source of gardening information.
