Lesson Plan of Components of Soils
General Science Grade V
Students’ Learning Outcomes
· Investigate and describe soil components.
· Describe the effects of moisture on soil characteristics, e.g. how it holds together soil and effects its texture and color.
Information for Teachers
· Soil is a mixture of organic and inorganic materials together with water and air.
· The organic part includes the living things and the dead remains of the things that lived once. The wastes of living things together with dead animals is called humus
· The inorganic part is made up of particles of rocks and minerals like sand, silt and clay.
· The properties of soil undergo drastic change in the presence of water.
Material / Resources
Different types of soil, water, plastic trays and magnifying glass, textbook.
Worm up Activity
· Call a group of students (2-3 volunteers) and ask them to spread wet ground soil in the tray and observe it through a magnifying glass.
· Ask them to look whether some living organisms are present in the soil.
(Expected response: Yes)
· Tell the students that moisture plays a major role In the chemical, biological and physical activities that take place in the soil. Chemically the moisture transport fertilizers and other chemical substances through the soil. Moisture also affects soil properties much as colour, texture, pH and fertility. Organic material stores much of the water and nutrients the plants need.
· Ask some students to take a sample of top soil from the school garden and put in a glass jar. Dig further and take another sample of soil at a depth of almost two feet. Mix the two samples and add small pieces of gravel.
· Fill glass jar with water.
· Cap the jar and move it upside down to mix the contents with water.
· Next day observe the different layers of the soil which have been visible in the jar.
· Ask students the following questions:
1. How many layers can you see in the jar?
(Expected response: Three Layers)
2. What is the name of the top layer?
(Expected response: top soil)
3. What is present in the bottom layer?
(Expected response: small stones or gravel)
4. What is the name of the layer?
(Expected response: sub-soil)
· Inform the students that the top soil contains a lot of humus, minerals, water and air. This is the best part of the soil for the growth of plants. The roots of plants mostly grow here.
· Take a group of students under our supervision to the school ground and ask them to dig the ground. Very soon the students will find an astonishing creature in the soil, the earthworm. It is called farmer’s friend because it helps to aerate the soil.
· Inform the students that the microscopic living things in the soil like bacteria help to break down the waste matter and thus help to increase the fertility of the soil.
· Ask a few students to go out of school and collect some soil samples from different locations.
· Place these soils in different plastic trays, labeled, X,Y and Z
· Call some student’s and ask them to touch each soil
· Do you feel moisture (water) in the soils?
(Expected response: Yes)
· Inform the students that all types of soil contain moisture.
· With the help of this moisture various chemical, biological and physical activities keep on going in the soil.
· Call a group of students (not more than five) and ask them to take handful of soil from each tray A, B, C, D and E and tray to make balls with the help of water.
1. Is it possible to make balls with wet soil provide in given trays?
2. Are these balls fluffy and break up easily?
· Ask students to identify given soil samples in light of following information.
· The particles of sandy soil don’t cling together in the presence of moisture. Therefore it is not possible to make balls.
· It is not easy to make balls with wet silty soil and they break down easily. Silty soil is suitable for growing crops.
· The particles of clay soil cling together easily and can form balls which don’t break. This soil is suitable to make bricks and pots.
· Sandy soil is used to make glass.
Sum up / Conclusion
· Soil is mixture of organic and inorganic materials.
· The organic material includes the living things and the dead remains of the things that lived once.
· The moisture plays a major role in the chemical, biological and physical activities that take place in the soil.
· The moisture in the soil also affects soil properties such as color, texture, pH and fertility.
· In the presence of moisture the particles of clay soil can cling together while the particles of sandy soil and silty soil remain almost unaffected.
Ask the students following questions:
· How many layers are present in the soil?
· Why do earthworms come out of the soil during rain?
(Response: to breath air)
· How do earthworms increase the fertility of soil?
(Response: They make the soil porous so that air can travel and reach the roots)
· Name a material formed by the decay of plants, leaves and insects?
· Which layer of soil is the best for growing plants?
(Response: Top layer)
· Collect the sandy soil, silty soil and clay soil in there different glass jars. Add sufficient water and sow a few green peas in the soil. Keep the jars in sunlight. Observe the growth of plants after a few days.
· Answer the following questions.
1. Which jar has the maximum number of plants?
2. Which jar has the minimum number of plants?