THE FOUR MAJOR KINDS OF SOIL

Created By Gita Deonaraine-Sahadeo

SOIL TEXTURE

Texture refers to the size of the particles that make up the soil. The terms sand, silt, and clay refer to relative sizes of the soil particles and are what make up soil. Pick up a pinch of soil between your fingers, and rub it back and forth. You will quickly notice that the soil is made up of a many different sized particles. These particles give the soil its texture.

COMPARING THE SOIL PARTICLES

SOIL COLORThe color of soil can tell us a lot about it. Most of these are shades of black, brown, red, gray, and white.

The darker a soil is, the more nutrient rich it is. The darker color often indicates an increase in decomposed organic matter known as humus.

SOIL STRUCTURE

Soil structure is the arrangement of soil particles into small clumps, called peds or aggregates. Soil particles (sand, silt, clay) bind together to form peds. Structure correlates to the pore space in the soil which influences root growth and air and water movement.

Clayey Soil•Texture: Clay, being the smaller size of particles,

feels sticky.

•Color: Depends on the chemical composition of the clay. Clay soils can be any shade of yellow to brown to red depending on the dominant minerals.

•Structure: Clay is formed by small particles. It has flat flakes that fit snugly together, creating a dense mass, some considered to be "sticky“ as it is tightly packed.

Sandy Soil

•Texture: Sand, being the larger size of particles, feels gritty or grainy.

•Color: Sandy soil is lighter in color than other soil. It can looked like light brown, white, or light gray and some other colors in it like red ...if it has oxidized iron in it.

•Structure: No structure because it is loosely packed and lacks the ability to stick together.

Silt Soil

•Texture: Silt soil is finer than sand, and feels smooth and silky

•Color: Usually a brown to black in color.

•Structure: Silt soil is similar to loam soil but contains smaller ratios of both sand and clay particles.

*Silt soil retains water well and provide the proper growth medium for most plants.

Loamy Soil

• Texture: Loams are gritty, moist, and retain water easily.

• Color: Loam soil has the color of black or dark brown.

• Structure: Loam is soil composed of sand, silt, and clay in relatively even concentration (about 40-40-20% concentration respectively).

*Loam soils generally contain more nutrients and humus than sandy soils, and is considered to be the most desirable medium for growing crops and many types of plants.