Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Soil is the thin, uppermost layer of the Earth's surface where plants grow.
Soil provides plants with essential water () and minerals required for their growth and survival.
It acts as a natural home (habitat) for many living organisms such as earthworms, ants, beetles, and burrowing animals like rabbits.
Soil contains humus, which is the dark, organic part of the soil formed from decayed plants and animals. Humus increases soil fertility.
Soil stores air (containing gases like and ) and water () in the tiny spaces between soil particles, which are used by roots and soil-dwelling creatures.
Humans depend on soil for agriculture to grow food crops, and for raw materials like clay to make bricks and pottery.
📐Formulae
💡Examples
Problem 1:
Why do farmers add manure or fertilizers to the soil?
Solution:
Farmers add manure to increase the amount of humus and essential nutrients in the soil.
Explanation:
Plants absorb minerals and from the soil to grow. Adding manure ensures the soil remains fertile so that crops can produce a healthy yield.
Problem 2:
Name two gases found in the air pockets of the soil that are important for living things.
Solution:
Oxygen () and Nitrogen ().
Explanation:
Roots and soil organisms like earthworms need to breathe, while is essential for plant proteins.
Problem 3:
How does soil help in the production of food?
Solution:
Soil holds the roots of plants firmly and provides the necessary and minerals for the plant to grow.
Explanation:
Since all animals and humans depend on plants for food, the soil is the foundation of the food chain.