Sandy, silty and clay soils are found in freshwater biomes. They support a rich population of vegetation. The same soil may be used to enrich your garden and outdoor areas. Freshwater biomes are found in areas with freshwater rivers, streams, ponds and lakes. Moving water and still water create different types of freshwater biomes, each featuring diverse plant and animal life.
Clay particles are the finest of all soil particles, so small they cannot be seen with a standard microscope. Clay binds together well, creating a densely packed soil that's capable of holding a great deal of water. Clay soil holds enough water to double in volume. Wet clay is very sticky to the touch, while dry clay is hard. Clay is a dense soil, which does not allow for a lot of airflow, but it is nutrient rich.
Silt particles are larger than clay particles but are still invisible to the naked eye. Silty soil holds together well and stays soft even when dry. When wet, the soil is smooth to the touch. Water drains through silt, but the soil retains some moisture. Silt is often considered to be the most desirable of soils, as it allows air and water to flow naturally while retaining moisture and nutrients to feed plants.
Sandy soils are very loosely packed. Sand is the largest of all soil particles and allows air and water to circulate through the soil very well. Sandy soils do not retain much moisture or hold many nutrients, and soils containing a high level of sand are often classified as poor or undesirable. Many gardeners add richer silt or clay soils to sandy soil types in order to make the soil suitable for planting. Sandy soil is very commonly found in freshwater biomes of all types.