GRADE FIVE SCIENCE

Hello Boys and Girls, Very soon it will be time for school again. If you have any of your text books it would be good for you to start having a look at them. Have you covered your books as yet? Do ensure that everything is in order for your attendance at school on Monday September 5.

Have you enjoyed finding out about food? Did the topic make you hungry? Have you been checking on the foods that you eat? Do try as far as possible to have balanced meals. You do remember how important this is.

This week we will look at soil. It may not seem so exciting, but it is. We will see how different kinds of soil can affect plant growth. We will see that there are different kinds of soil and what happens to soil over time.

First let’s look at what is soil. Soil is the material that can be found on the outermost layer of the earth. It is where plant roots are often found. It forms the surface of the land. It is one of the main natural resources.

What colour is soil? Are all soils the same? What is soil made up of?

Soil is mostly made of small pieces of rock, but it also has air and water. Soil also has materials from dead plants and animals. The dead remains of plants and animals in the soil is called humus. It tends to be dark in colour.

Go out into the yard, dig up some soil and observe. Have you seen that there are different types of soil? Yes there are. Three of the most common ones are sandy soil, clay soil and loam.

Let’s look at sandy soil. Sandy soil is light and easily dug up. It has lot of air spaces in it so water drains through quickly. There are not many minerals useful to plants in this soil and not much water remains, so sandy soil is not the best kind of soil for many plants. Sandy soil has large particles.

Clay soil is heavy and does not allow water to pass through easily. You can imagine how sticky it is when it is wet. It allows plants to grow easily because it has more water and also has more minerals useful to the plant. However the roots of plants can sometimes rot because of waterlogging.

Let’s investigate loam. Is loam a good soil for growing plants? Why do you think so? Loam is very good for growing plants. It is sometimes called garden soil. It is made from a mixture of clay and sand. It also has a lot of humus in it. Loam holds a lot of water, has air spaces and has a lot of useful minerals in it.

In the table below compare sandy soil, clay and loam. Which of these types of soil do you consider to be the best soil? Why? Draw a picture of each type of soil and label them.

Study the picture of some soil below then discuss with a friend what is being shown. Until then, goodbye Boys and Girls. We will examine this next week.