Soil texture measures the size of the particles that make up your soil. Given that it took several millennia for these particles to reach the size they now are, this is not one of the things you can easily change in your soil.
The texture is determined by the proportions of different sized particles in your soil. There are three main categories:
• Sand - particles ranging in size from 0.05 mm to 2.0 mm
• Silt - particles ranging in size from 0.002 mm to 0.05 mm
• Clay - particles <0.002 mm
|Here is a picture that gives you an idea of the relative sizes of these particles.|
A lab can tell you what your soil texture is but it's fun and easy to get a good idea with this test.
• Collect a cup or so of soil from about 3 inches below the surface.
• Add one cup of soil and two cups of water to a clear glass jar like a mason or pasta sauce jar.
• Put the lid on tightly and shake it up until all the soil is suspended in the water.
• Put the jar in a place where it can stay for 24 hours. You will take three measurements over the next 24 hours.
• Measure after one minute to get the depth of sand.
• Measure after one hour to get the depth of silt.
• Measure after 24 hours to get the depth of clay.
• Do the math.
This usda chart shows how, once you have your figures you can name your soil.
Even though you can't change your soil's texture, it dictates the way you will manage your soil. You need to add extra organic matter to both clayey and sandy soils. And when adding soil amendments you add less to sandy soils than to the loamy or clayey soils. This is because in sandy soil it tends to leach out very quickly which wastes whatever you are adding and can contaminate your ground water.