Question

When a small amount of garden soil is put into a glass jar containing water, stirred and allowed to stand for two hours, the layers from top to bottom would be:

• A. Debris, water, sand and clay
• B. Humus, water, clay and sand
• C. Debris, clay, gravel and sand
• D. Humus, sand, gravel, and clay

Answer 1

The correct option is A Debris, water, sand and clay

The soil is a complex mixture of various minerals and organic matter. When soil is mixed with water, it forms a suspension where soil particles remain suspended in water for sometime and then gradually settle down and form layers according to their weight. Clay settles down first as it is the heaviest component of soil and forms the lowest layer. Sand is lighter than clay, so forms a layer above it, whereas soil debris floats on the water surface as it consists of very light and small, scattered fragments of loose and wrecked materials like leaf pieces, twigs, etc.