Students’ Learning Outcomes
· Identify similarities and differences among the different types of soil.
Information for Teachers
· Upper must layer of Earth is called soil. At some places it goes down to the depth of several feet while at other places it remains just a few inches thick.
· Soil have many different properties, including particle size, texture, structure, water holding capacity, colour, acidity and alkalinity.
· Soil may be similar or different depending upon the properties they possess.
· Soil may contain sand, silt and clay.
Material / Resources
Different type of soils, plastic trays, magnifying glass, textbook
Worm up Activity
· Soil like air and water, one of the most important natural resources. Most of our food grows in soil. It is the home for billions of organisms. We build homes and buildings on it.
· Soil are formed very slowly, may be as little as 1cm of thickness in 500 years, so we can’t just replace them in our own life time. However, in some areas, the floods can replace of the top soil almost every year.
· Many of our soil types are being damaged and are at risk of change. It is important that we understand importance of soil and make sure that it remains intact for use of future generations.
· After this introduction announce the topic of today and start by asking the following questions.
1. What is soil?
2. Do you know how soil is formed?
3. What is the texture of soil?
· After these questions introduce them that the way a soil feels in called the soil texture, it may be gritty, floury or sticky.
· Inform students that soils differ in their particle size, colour, texture and humus content.
· Take five samples of soil from different places on the separate plastic trays and label them A, B, C, D and E.
· Divide students in small groups (4-5 members in each group)
· Ask students to pick some quantity of soil from all the trays one by one and note down their following characteristics in the table given below. (you may use magnifying glass if needed)
· Characteristics that should be observed are colour, texture, size and weight of the particles, dampness.
Colour(Grey, Dark grey, Bluish grey
Size of particles(Small, Larger, Largest)
Weight of particles (Heavy,/Light, heaviest
Dampness or Dryness
· Inform the students if the soil particles are greyish in colour, light in weight and larger in size, then the soil is called sandy soil.
· If the soil particles are bluish grey or bluish green, smooth and silky, heavier in weight and smaller in size, then this soil is called silty soil or loam.
· If the particles of the soil are bluish green or bluish grey, smooth and soapy, smallest in size and are heaviest in weight then soil is called clay soil.
Sum up / Conclusion
· In sandy soil, particles are light in weight. It can’t hold water and nutrients. They can easily be drained.
· In silty soil, particles hold water; can be hard to drain, and hold limited nutrients.
· Clay particles hold water well, can become heavy and water logged and can hold onto nutrients.
Ask students the following questions:
· In which type of soil water flows very easily?
(Expected response: Sandy Soil)
· How do plant roots and insects present in the soil breath?
(Expected response: Air fills the gape present in soil and allows the plant roots and insects to breath)
· What characteristics should be present in soil for plant growth?
(Expected response: small size of soil particles, humus soil and its ability to hold water into it are favourable for plants to grow.
· Go to nearby nursery; get hold of the sample of soil in which plants grow and note down its characteristics.