Second Term Lesson Note for Week Two
Class : Primary 4
Subject: BASIC SCIENCE AND TECHNOLOGY
Topic : Soil and its constituents
Duration : 40 minutes
Periods : Single Period
Previous Knowledge : Learners have previous knowledge of
Measurement of Length, Area of objects
that have been taught in their various previous classes
Learning Objectives : By the end of the lesson , learners willbe able to:
i. Define soil and Identify the constituents of soil;
ii. List the types of soil and explain them.
iii. Discuss the uses of various constituents in the Soil and uses of soil.
Instructional Material : Wall charts and Pictures of types of soil
METHODS OF TEACHING :
- Class Discussion
- Group Discussion
- Asking Questions
- Explanation
- Role Modelling
- Role Delegation
REFERENCE MATERIALS :
- Stan Basic Science and Technology for Primary Schools, UBE Edition, Book 4
- Lagos State Unified Scheme of Work for Primary Schools , (Primary 4 – 6);
- Online Resources
Content :
Soil and its Constituents
Soil is formed by slowly breaking down of rocks into smaller pieces by agents such as living things, wind, heat, water, ice.
The process of breaking down rocks into smaller pieces is known as weathering.
Soil is made up of particles of different sizes due to this process of weathering.
Other things found in the soil are decayed plants and animals. Soil also contains air. The quantity of air depends also on the type of soil.
Soil is essential for the development of most plants, providing physical support and nutrients.
Constituents of Soil
Constituents of the soil are the parts of which soil is made up. It is the combination of substances that form the soil.
The constituents of soil are:
- Air
- Water,
- Mineral particles and
- organic matter.
Importance of Constituents of Soil.
i) Air: Air looses the compartment of soil and create a good condition for plant growth.
ii.) Water : Water keeps the soil moist and wet, thus reducing excess heat in the soil.
iii.) Mineral particles: These are sources of mineral elements present in the soil.
iv.) Organic matter (dead and living organisms) : These give the soil valuable plant nutrients, hold water in the soil, improve the soil structure to absorb more heat.
Among organic matter are leaf litters. Leaf litters are dry leaves that are left on the soil surface.
Types of Soil
Soil is classified based on the sizes of the particles. The three are main types of soil, we have :
i. Sandy soil
ii. Clayey soil
iii. Loamy soil
Properties of Soil
Each type of soil has specific properties.
- Sandy soil:
i. Contains fairly large particles and big pore spaces.
ii. Sandy soils are easy to till, well-drained and aerated.
iii. They are easily washed away because if their looseness
iv. They are greyish or brownish in colour.
- Clayey soil:
i. They have the smallest particles, which are tightly packed.
ii. They can hold water and thus, are nit well drained.
iii. Their colours can be red, reddish brown or white
- Loamy soil:
They are the mixture of sand and clay particles with high proportion of organic matter. Loamy soils are the best soils for planting crops.
Silty soil:
i. They contain smaller particles and pore spaces.
ii. Particles are tightly parked and barely visible to the naked eye.
iii. Silty soils are fairly easy to till, well drained but do not loose water as quickly as sandy soil.
Soil Profile
Soil profile is the layers to which soil is divided. Soil is divided into four. These are:
i. Top soil
ii. Sub soil
iii. Rock particles
iv Solid rock layer
The Soil Profile
Soil texture: This is how a soil type feels when handled. For example, sandy soils feels loose, while clay soils feel sticky when held
Soil structure: This refers to the manner in which soil particles come together to form clumps.
Presentation Steps:
The topic is presented step by step
Step 1: The teacher revises the previous topics with the learners by asking questions orally.
Step 2 : He/ she introduces the new topic to the learners by asking them to define soil and identify its constituents
Step 3 : The teacher allows the pupils to give their own examples and he corrects them when the needs arise
Step 4 : He/ she then
Evaluation
1. _________ is the uppermost layer of the earth on which plants and animals live.
2. Soil is formed from __________________.
3. The process of forming soil from rock is known as _____________.
4. The substances or materials found in the soil are referred to as ____________ of the soil.
5. Mention the soil constituents that you know: _______________, _____________, ________________ and _______________.
6. There are ___________ types of soil.
7. List the types of soil.
8. State three uses of the soil.
Conclusion :
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.
Assignment :
1. Draw and label the soil profile
2. Explain the following:
i. Soil texture
ii. Soil structure
3. State two characteristics of each type of soil.