Soil is major part of the environment.
without soil we can't exist. The soil profile
layers can be easily identified by the texture
and color of the soil. The topmost layer of
the Earth’s crust is the soil. These layers of
the Earth’s crust help to grow and support
Sand, Silt, Clay and Loam
Sand: The first type of soil is sand.
• The size of sand particles range between 2.0 mm and 0.05
Silt: Small particles, and size is between sand and clay.
• Silt size as 0.05 mm and 0.002 mm.
Clay: very fine particles.
• less than 0.002 mm.
Loam : It is the fourth type of soil.
• It is a combination of sand, silt and clay such that the
beneficial properties of each are included.
What is the Difference Between Sand,
Silt, Clay and Loam
The main difference between sand silt and clay is their
particle size. Sand particles are larger in size while clay
particles are extremely fine, and silt particles are somewhere
in between sand and clay particles.
Parent material- transported from else where, usually by wind
or water at different speed.
Climate- The characteristics of weather as they over time
scales longer than those necessary for soil properties to
Topography- The term topography refers to the configuration
of the land's surface. and the general shape and connectivity of
Biological- Plants, animals, microscopic organism humans
interact with soil in different ways.
Time- The amount of the time it takes for the above four
factors to interact with each other.
The soil is arranged in layers or in horizons.
They are arranged during their formation.
The layers or the horizons are basically known
as the soil profile.
Soil horizons are the layer in a soil profile used
to classify soil type.
O Horizon:- The origin matter horizon surface layer at
depth of 0-2 feet, Dark in color, soft in texture.
• Humus- Rich organic material of plants and animal origin
in a stage of decomposition.
• Leaf litter- Leaves, needles, twinges, moss, lynches that
A Horizon:- “Top soil’’ or “Biomantle” horizon. Top most
layer of mineral soil, at depth of 0-10 feet.
• Some humus present, darker in color than layers blow.
• Biomantle- Most biological protective layer; earthworm,
fungi and bacteria live this layers (soft soil)
• Smallest and finest soil particles.
E Horizon:- small layer between A and B Horizons
• At depth of 10 to 15 ft
• E Horizon also called leaching layer.
• Leaching is some how water is present.
• E Horizon light in color, mainly sand and silt.
• Poor mineral and clay content due to leaching.
• Leaching are the loss of water returning plant nutrient
to the water table
• Soil particles are larger than in A Horizon but smaller
than B horizon.
• B Horizons are also called as sub soil Horizon
• At depth of 10 to 30 feet.
• Rich in clay and mineral like Fe and Af.
• Red and brown in color due to Oxides of the fe
C Horizon:- The “Saprolite” horizon.
• At Depth of 32 to 48 feet.
• Made up of large rocks or lumps of partially
• Least affected by weathering and have charged
the least since their origin.
• The “Bedrock” Horizon.
• At Depth of 48+ feet .
• Deepest soil horizon in the soil profile.
• Continuous mass of Bedrock.
• No rock or Boulder only a continuous mass of Bedrock.