LESSON 2: TYPES OF SOIL, THEIR DIFFERENCES AND PROPERTIES.

TYPES OF SOIL

Sand, silt, and clay are the basic types of soil. Most soils are made up of a combination of the three. The texture of the soil, how it looks and feels, depends upon the amount of each one in that particular soil. The type of soil varies from place to place on our planet and can even vary from one place to another in your own backyard.

Soil Types

People describe soil types in all kinds of ways such as heavy, light, sandy, clay, loam, poor or good. Soil scientists describe soil types by how much sand, silt and clay are present. This is called texture. It is possible to change the texture by adding different things. Changing texture can help in providing the right conditions needed for plant growth.

Sand is the largest particle in the soil. When you rub it, it feels rough. This is because it has sharp edges. Sand doesn't hold many nutrients.

Silt is a soil particle whose size is between sand and clay. Silt feels smooth and powdery. When wet it feels smooth but not sticky.

Clay is the smallest of particles. Clay is smooth when dry and sticky when wet. Soils high in clay content are called heavy soils. Clay also can hold a lot of nutrients, but doesn't let air and water through it well.

Particle size has a lot to do with a soil's drainage and nutrient holding capacity. 

To better understand how big these three soil particles are, think of them like this. If a particle of sand were the size of a basketball, then silt would be the size of a baseball, and clay would be the size of a golf ball. Line them all up, and you can see how these particles compare in size.

 Loam is soil composed of sand, silt, and 

clay in relatively even concentration 

(about 40-40-20% concentration 

respectively).^[1] These proportions can 

vary to a degree however, and result in 

different types of loam soils: sandy loam, 

silty loam, clay loam, sandy clay loam, 

silty clay loam, and loam.^[1] Loam soils 

generally contain more nutrients, moisture 

and humus than sandy soils, have better 

drainage and infiltration of water and air 

than silty soils, and are easier to till than 

clay soils. The different types of loam 

soils each have slightly different 

characteristics, with some draining 

liquids more efficiently than others.

Loam: