Dry clay soil can make plant growing difficult.
ASTM International, which evolved from the American Society for Testing Materials, is an international organization that establishes and regulates technical standards for products and materials. These materials include soil that people use for agriculture, gardening, landscaping, outdoor construction projects and other applications. ASTM International bases its soil classifications on the quantity of soil particles that are able to pass through sieves or sifting implements. Detailed soil classification information is available in ASTM International's D2487 document, which is linked in the Resources section.
Fine-Grained Soil
ASTM International classifies a fined-grained soil as any soil that allows for 50 percent or more of its particles to pass through a No. 200 sieve. The No. 200 sieve has openings that are 0.075mm or about 0.003 inches wide.
Coarse-Grained Soil
Coarse-grained soil is the opposite of fine-grained soil. ASTM International classifies a coarse-grained soil as a soil that does not allow 50 percent or more of its particles to pass through a No. 200 sieve.
Gravel
Gravel is a well-known type of coarse-grained soil that consists of small stones and other mineral particles. ASTM International classifies gravel as a soil that can pass through a sieve with 75mm or 3-inch openings but cannot pass through a No. 4 sieve. A No. 4 sieve has 4.75mm or about 0.2-inch openings.
Fine Gravel
ASTM International classifies fine gravel as a soil that can pass through a sieve with openings that are 19mm or 3/4 inch wide.
Coarse Gravel
Coarse gravel, according to ASTM International standards, is gravel that cannot pass through a sieve with 19mm or 3/4-inch wide openings.
Sand
Sand is a mixture of tiny rock and mineral particles. ASTM International classifies sand as a soil that can pass through a No. 4 sieve, which has 0.2-inch openings, but that cannot pass through a No. 200 sieve, which has 0.003-inch openings.
Fine Sand
According to ASTM International, fine sand is a sand that is able to pass through a No. 40 sieve, which has 0.475mm or about 0.02-inch openings.
Medium Sand
Medium sand is a sand that can pass through a No. 10 sieve, which has 2mm or about 0.08-inch openings, but cannot pass through a No. 40 sieve, which has 0.02-inch openings.
Coarse Sand
ASTM International classifies coarse sand as sand that can pass through a No. 4 sieve, which has 0.2-inch openings, but that cannot pass through a No. 10 sieve, which has 0.08-inch openings.
Clay
Clay, according to ASTM International, is a soil that can pass through a No. 200 sieve, which has 0.003-inch openings. When wet, clay soil demonstrates plasticity, meaning it is easily moldable. When dry, it becomes strong.
Silt
Silt, like clay, is a soil that can pass through a No. 200, 0.003-inch sieve. Silt, however, does not demonstrate plasticity when wet and is not strong when dry.
Related posts
Break Down Clay SoilSoil types are described by how much sand, silt or clay the soil contains. Although most soil contains a combination of these particles, the exact combination determines the so...
Most soils can be amended to support a lawn.A lush, green lawn is not an accident, but rather the result of careful planning, preparation, planting and care. Soil is the turf's growth medium and i...
Use a Soil HydrometerA hydrometer is a relatively simple piece of laboratory equipment used to measure the specific gravity of the density of a liquid. When used to test soil, a hydrometer measure...
Clay soil has finer particles than silt or sand, making it more challenging to aerate.Among sand, silt and clay soil textures, clay has the least natural tendency to aeration, tending to be highly...
Gardening with clay soil may be difficult because of its dense composition.Clay soil is dense and rich, holding a lot of the nutrients plants need to thrive. Made up of small particles, clay feels...
