5 Interesting Facts About Clay Soil

Clay soil has some remarkable characteristics. Alone of all soil types, clay can be used naturally to form barriers against moisture and erosion, for example. In a pure clay form, it is not well suited for most plants, but the natural plasticity of clay makes it easy to mix. Here are 5 interesting facts about clay soils, why they special, and how they can be used.

Fact 1: Classes of Soils

There are 3 main types of soil: clay soil, sandy soil and loamy soil. Clay and sand are effectively opposites, with loamy soil being ideal for the growth of plants. Where sandy soil is made up of visible grains, clay soil is much finer, with the individual grains much more difficult to discern. Because they are so small, clay grains are able to align, binding with other clay particles to form a substance that is able to resist water seepage. This alignment is the reason that clay feels slippery, as the grains slide almost without friction against each other. The common misconception is that things slide easily on clay, but the fact is that clay binds to other materials, and then slides against itself.

Fact 2: Types of Clay Soil

While most clay soil is inorganic, it can also be found as sedimentary deposits that have eroded from other locations and mixed with organic matter as it was transported. This type of clay tends to be found in mountain valleys, or in low lying areas that have intermittent flows of water. Organic clay mixtures are darker in color, and are often streaked with darker lines formed by layers of decomposed plant matter.

Fact 3: Uses for Pure Clay

If conditioning the clay soil is not what you have in mind, clay can be used to define garden borders, preventing excess flooding during heavy rains, and channeling the garden drainage to the desired location. Clay forms a natural barrier to moisture, and can be used as the central fill for berms, dikes or small dams. Additionally, clay can be formed into different shapes, and fired or baked. Sun-dried bricks can be made by shaping small blocks and leaving them in direct sunlight.

Fact 4: How Clay is Conditioned

To condition clay soils for use in planting, the addition of sand is required to increase the ability of air and water to move through the soil, and humus should be added to increase the amount of organic compounds available to fuel plant growth. Add approximately 1 part of humus and sand for each 5 parts of clay being treated. Turn the area being conditioned with a tiller until the three soil types have been well mixed.

Fact 5: How Clay Soil is Beneficial

Clay soil is unique in that it can retain moisture, making conditioned clay excellent for use in dry climates. It also adds density to the soil, which allows plants to grow stronger and taller. Pure clay inhibits root growth, but conditioned clay soils offer an almost optimal support for bushes, shrubs and trees.