Theory question 206
Soils(a) Define soil. (b) Outline three characteristics of the following soil types: (i) Sandy soil; (ii) Clay (c) Highlight four ways in which soil is important
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(a) Soil is the thin layer of loose material on the earth's surface made of weathered rock particles, humus, water, air and living organisms, in which plants grow.
(b)(i) Sandy soil: large, coarse particles; very porous and drains quickly; holds little water and few nutrients (leached); light and easy to cultivate; warms quickly.
(ii) Clay soil: very fine particles; holds water and becomes waterlogged; sticky when wet and cracks when dry; poorly aerated; rich in nutrients; heavy and hard to till.
(c) Medium for plant growth and farming; supplies nutrients and water to plants; raw material for bricks, pottery and building; habitat for organisms; supports grazing and forests; foundation for buildings and roads; filters and stores water.
Compare the two soils by particle size, drainage and fertility.