Soil - Types And Characteristics
Transcript
00:00Hi kids! Today we will learn about different types of soil. So let's start!
00:10There are three basic types of soil. Sand, silt, and clay.
00:18All types of soil are mainly made up of small particles of weathered rocks.
00:24That is, very small broken pieces of rocks.
00:29And different types of soil are differentiated by the size of rock particles in them.
00:36Now let's learn about sand.
00:40It is characterized by largest rock particles that do not stick together
00:46and this type of soil, that is, sand, does not hold any water.
00:52Sand is fairly coarse and loose so water is able to drain through it easily.
00:59While this is good for drainage, it is not good for growing plants
01:05because sandy soil will not hold water or nutrients.
01:11Take some sand in a strainer and add water.
01:16Water will easily drain through the sand.
01:20So sand is not good soil for growing plants
01:24because it does not hold water and nutrients that are required for the growth of plants.
01:32Now let's see another type of soil which is called silt.
01:38Silt has bigger rock particles than those of sand.
01:43It holds some water in contrast to sand which does not hold any water.
01:50Silt is a type of soil which is mainly deposited by rivers.
01:57Let's learn more about it.
02:00A river, when flows down a mountain,
02:04brings with it some weathered or broken rock particles from the mountains.
02:10When the river reaches lower areas,
02:13it deposits those fine particles on the banks of the river and riverbeds.
02:19It seems like very fine sand which is soft to touch.
02:24And this deposited sand is called silt.
02:29Now put some silt in a strainer and now pour water on it.
02:35Water will drain through the silt slowly as compared to sand.
02:40So silt holds some water and water drains through silt slowly,
02:46then that through sand.
02:49Now we will learn about clay.
02:53Clay has the smallest rock particles among all types of soil.
02:59They stick together very close to each other.
03:03It is very silky and smooth to touch and holds good amount of water.
03:09That is, if you add water to clay, much of it will stay in the clay.
03:16Now take some clay in a strainer and now again pour water on it.
03:23What do we see?
03:25Very little amount of water will drain through the soil.
03:30And that too very slowly because clay holds the water
03:35and water drains through it very slowly.
03:39Clay does not drain well and does not provide space for plant roots to breathe.
03:46So only clay in the garden is also not a good option
03:51as it won't let plants grow properly.
03:56Clay soil is used to grow roses, bergamots, compass plant and partridge pea.
04:07Clay can be fired or dried in the sun to make bricks
04:12which are then used in construction of buildings.
04:16Clay combined with straw and sand makes cob.
04:20And cob is a construction material which is used to make buildings, ovens and benches.
04:29Clay soil is also used to make walls, floors, countertops, ceramic tiles.
04:37Now here we have another type of soil which is loam.
04:43Loam is a mixture of sand, silt and clay.
04:49The quality of loam soil depends on the quantity of various types of soil in it.
04:57This is why loam soil is always the first choice of a gardener
05:03as it's best for plant growth since it is a mixture of all types of soil and it has humus too.
05:12So it holds good amount of moisture and also allows good drainage.
05:19The decaying plant and animal matter help give structure to the soil to hold the plant roots in place.
05:29Loam also holds just the right amount of water, neither too less nor too much.
05:38It lets some water in which allowing the extra to drain.
05:43Ingredients of loam are sand, silt, clay and humus.
05:50Loamy soil is ideal for plant cultivation and is commonly used to grow flowers, fruits and a variety of vegetables.
06:01Loamy soil in combination with straw is also used in wall construction
06:07and applied on the inner surface of walls to control humidity.
06:14Now let's revise what we have learned about types of soils.
06:21We learned about four types of soil.
06:39It is the mixture of all types of rock particles and humus.
06:44Now let's learn what humus is.
06:50Humus is dark organic matter in soil which is made up of dead and decayed plant and animal matter.
06:58Like when small insects and animals die in the soil, their bodies turn into humus.
07:06Likewise, plant waste like dropped leaves, twigs, fruits and seeds too form humus.
07:15So humus is the remains of living material and becomes a part of the soil
07:21which makes it very fertile as it adds to the amount of nutrients in the soil.
07:28So kids, today we learned a lot about different types of soil and their characteristics.
07:36Now you may go ahead and take a quiz to learn more.
07:40Bye-bye!