Sandy loam soil is a type of soil used in plant beds and pots that require ample drainage for the plants to thrive. Soil types are based on the ratio of materials in the soil. Though soil type is most accurately determined through a soil test, observing the properties of soil can help render clues to determine its type.
Sandy loam soil is a mixture that is generally well-balanced, but has sand as a dominant component. Perfect loamy soil is ideal for most growing, and contains an even mixture of sand, silt and clay in roughly even proportions. Sand, silt and clay are defined by different particle types in soil identification.
Each soil type has distinct properties that change when water is added to the soil. Dry sandy loam soil forms into a ball that falls apart readily when touched. When it is lightly wet, it forms a crumbly ball and will hold some finger marks when squeezed.
Sandy loam is ideal for plants that need more soil drainage than usual. A chronic incurable "overwaterer" will appreciate the drainage benefits sandy loam soil provides, since good drainage in soil decreases the chance of plant disease. The large soil particles of sand in sandy loam soil increase the soil's capacity to let water flow through, making it easier for fresh water to move through the planting media.
Sand consists of larger particles than silt, and silt has larger particles than clay. Sandy loam contains less than 70 percent sand and has somewhat less sand than loamy sand, which contains 70 to 90 percent sand.
Types of sandy loam are categorized by the size of the sand and include coarse sandy loam, sandy loam, fine sandy loam and very fine sandy loam. Very fine sandy particles will provide less additional drainage to a soil mixture than larger coarse sand particles. Fine sand tends to be smoother in appearance than coarse sand, which appears as larger flecks in a bed of otherwise loamy soil.