Soil (constituents) : Air Water Leaf litters Small rocks Dead animals and Living animals

Subject : 

Basic Science and Technology

Term :

Second  Term


Week 2

Class :

Basic 4 / Year 4 / Primary 4


Previous lesson : 

The pupils have previous knowledge of previous topics that have been taught in the previous class

Topic :

Soil (constituents) : Air, Water Leaf litters, small rocks ,Dead animals,  and Living animals

Behavioural objectives :

At the end of the lesson, the pupils should be able to

  • Define soil
  • Explain the meaning of constituents
  • Give examples of soil constituents which are air , water , leaf litters , etc.


Instructional Materials :

  • Wall charts
  • Pictures
  • Related Online Video
  • Flash Cards

Methods of Teaching :

  • Class Discussion
  • Group Discussion
  • Asking Questions
  • Explanation
  • Role Modelling
  • Role Delegation


Reference Materials :

  • Scheme of Work
  • Online Information
  • Textbooks
  • Workbooks
  • 9 Year Basic Education Curriculum
  • Workbooks


Content :

What is soil?

Soil is the upper part of the earth surface that supports animal existence and plants growth . Soil is made when rocks are broken down into smaller units or forms ,. These process of breaking down rock to form soil is known as weathering .

The composition or constituents  of soil

Soil is made up of particles of different sizes. Besides soil particles, there are many other things in the soil. All plants grow in the soil, and their roots are inside the soil. Some animals live in the soil but, from time to time, they come to the surface. When plants and animals die, their dead bodies remain in the soil where they become rotten and later form part of the soil as humus. Let us find out more about things in the soil.

Things in the soil

Many living things can be found in the soil. Some animals like earthworms and termites can only live inside the soil. Living plants and animals are not the only things in the soil. The soil also contains parts of dead plants and animals.

Types of soil

There are three main types of soil and these are:-

  1. Loamy soil
  2. Sandy soil
  3. Clayey soil

Air in the soil

Soil particles have spaces between them. As you probably know, what is in these spaces is air.

Properties of soils

We have found out that soil is made up of particles of different sizes. Some are large and some are small. We will now learn more about soil particles and how soils are different in the way they allow water to pass through them

Soil particles

We can find out about the different particles of soil if we shake up the mixture of soil in water and allow this soil and water mixture to settle down


Soil constituents are the properties that combine together to form soil . These are

Air : Air is a mixture of gases . Air bubbles are form in the air and these are seen in as bubbles as they escape from sand when water is poured on the sand

Water : Water is liquid . Water is made up of two gases which are oxygen and hydrogen . Water is always available in the ground as water supports plants growth .

Leaf litters : Dead decaying leaves fall off from trees and they also form parts of soil as they decay and add nutrients to the soil

Small rocks : Small rocks are the products of rocks being broken down into smaller units and forms . This is the end result of climatic factors reacting with rocks

Dead animals : These dead animals are small animals like rodents, earthworms or insects that lived and died in the soil

Living animals :  These are living micro organisms that live in the soil . These are crickets , earthworms or other smaller animals

  1. Which of the following is NOT an example of organic matter found in soil? a) Dead plant material b) Animal waste c) Minerals d) Decaying organic matter
  2. Which of the following is responsible for breaking down organic matter in soil? a) Minerals b) Water c) Microorganisms d) Insects
  3. Which of the following is NOT a common mineral found in soil? a) Clay b) Sand c) Silt d) Carbon
  4. Which of the following is important for aerating the soil? a) Microorganisms b) Water c) Air d) Insects
  5. Which of the following is responsible for holding water in the soil? a) Roots b) Microorganisms c) Organic matter d) Minerals
  6. Which of the following is important for controlling plant diseases in the soil? a) Microorganisms b) Insects c) Water d) Air
  7. Which of the following is responsible for providing essential nutrients to plants in the soil? a) Insects b) Water c) Organic matter d) Air
  8. Which of the following is important for anchoring plants in the soil? a) Minerals b) Microorganisms c) Roots d) Insects
  9. Which of the following is responsible for promoting soil fertility? a) Air b) Water c) Microorganisms d) Minerals
  10. Which of the following is NOT a common invertebrate found in soil? a) Worms b) Beetles c) Ants d) Snakes



The topic is presented step by step

Step 1:

The class teacher revises the previous topics


Step 2.

He introduces the new topic


Step 3:

The class teacher allows the pupils to give their own examples and he corrects them when the needs arise




The class teacher wraps up or conclude the lesson by giving out short note to summarize the topic that he or she has just taught.

The class teacher also goes round to make sure that the notes are well copied or well written by the pupils.

He or she does the necessary corrections when and where  the needs arise.



  • Define soil
  • Explain the meaning of constituents
  • Give  four examples of soil constituents .
  • Define soil particles .
  • State three kinds of soil .
  • Explain four uses of soil .




  1. __________ provide the necessary physical structure to support plant growth in soil.
  2. Soil is composed of a variety of __________, such as clay, sand, and silt.
  3. __________, such as dead plant material and animal waste, provide essential nutrients to plants in the soil.
  4. __________, such as bacteria and fungi, are important for decomposing organic matter in the soil.
  5. Insects and other __________ are important for breaking down organic matter and aerating the soil.
  6. __________ are a crucial component of soil, anchoring plants in place and absorbing water and nutrients.
  7. Soil acts as a reservoir for __________, holding moisture that plants can use for growth.
  8. The spaces between soil particles allow for __________ to circulate, which is important for root respiration and the growth of soil microorganisms.
  9. Microorganisms in the soil can help control __________ and promote soil fertility.
  10. The most common minerals found in soil include clay, sand, and __________


Multiple-choice questions:

  1. c) Minerals
  2. c) Microorganisms
  3. d) Carbon
  4. c) Air
  5. c) Organic matter
  6. a) Microorganisms
  7. c) Organic matter
  8. c) Roots
  9. c) Microorganisms
  10. d) Snakes

Fill-in-the-blank questions:

  1. Minerals
  2. Minerals
  3. Organic matter
  4. Microorganisms
  5. Invertebrates
  6. Roots
  7. Water
  8. Air
  9. Plant diseases
  10. Silt


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