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00:00Hi kids, today we will learn about soil, so let's start.
00:09Soil is the topmost layer of earth, or the skin of earth, which is mainly made up of
00:15a mixture of minerals, small or big rock particles, clay, water, and organic matter.
00:26This topmost layer of earth is responsible for all the life on earth, as almost all types
00:33of plants grow in this layer of the earth.
00:38And we know ultimate source of food for all living things is plants.
00:45Now let's learn the components of soil.
00:49First is the organic matter.
00:53It is dead and decaying plant and animal remains.
00:59Then is the nutrients and minerals.
01:04Nutrients are substances that all living things need in order to grow.
01:09And minerals?
01:10Mineral are the nutrients found in soil, and it comes from the different types of rocks
01:16in soil.
01:19Air and water.
01:20Air and water are present inside the soil pores.
01:26During dry season, air is more in the soil, and during wet season, water is more inside
01:33the soil.
01:38Microorganisms and small animals.
01:41All living organisms like worms, ants, termites, gastropods, anthropods, and nematodes are
01:51there in the soil.
01:55So kids, we learned the components of soil.
02:00Now let's learn some important functions of soil.
02:05It stores minerals.
02:09Soil contains various minerals that act as the nutrients for the plants.
02:14Soil contains both organic and inorganic mineral matters.
02:21Inorganic minerals are derived from weathering of rocks.
02:27They can be magnesium, sodium, potassium, iron, aluminum, sulfur, chlorine.
02:38And organic minerals are derived from decaying plants and animal remains.
02:47Inorganic minerals provide calcium to the plant, whereas organic minerals provide nitrogen
02:54to the plant.
02:57Water provides hydrogen to the plants.
03:01Air provides carbon dioxide to the plants.
03:07Soil stores water.
03:10Soils consist of particles and pores, and these pores can be filled with air, but also
03:17with water.
03:19The amount of pores in a soil is different for different types of soil.
03:25The process of water entering the soil is called infiltration.
03:31When the soil has taken up all the water it can, we say that it is saturated.
03:40Soil purifies water.
03:43When rainwater passes through the different layers of soil, it filters out the water and
03:49purifies it.
03:52Soil works as a physical strainer, a biochemical renovator, and a biological recycler for all
04:00waste water passing through it.
04:05Soil acts as a habitat for many types of organisms.
04:12Soil is the habitat of both macro and micro organisms.
04:19Micro organisms are worms, rodents, and insects.
04:25Micro organisms are fungi, bacteria, algae, and protozoa, etc.
04:34And these macro and micro organisms are very important.
04:39Earthworm aerate the soil, that is create spaces for air in the soil, and also helps
04:48to disintegrate and mix its constituents by passing large quantities of soil through
04:56their bodies, and ejecting the same on the surface as worm gas.
05:04The quantity of soil passed through the bodies of earthworms is enormous.
05:11It is estimated that earthworm transport about 10 tons of soil per acre per year.
05:20The soil ejected by the earthworms possesses better fertility than the original soil.
05:28This activity of earthworms leads to the transfer of soil from the lower layers to the surface.
05:36The small burrows created by the earthworms provide the facility of aeration and drainage
05:44in the soil.
05:48Soil is the medium for plant growth.
05:52Soil is the medium that fulfills all the requirements of a plant for its growth.
05:59There are other mediums too.
06:02Plants can grow in water and some aerated nutrient solutions too.
06:08But the main and most common medium for plants to grow is definitely soil.
06:16Let's see requirements of a plant that are met by soil.
06:22Mechanical support.
06:23Roots anchored in the soil enable growing plants to remain erect.
06:29Plants stand erect because of the hold exerted by the soil on plant roots.
06:39Nutrient supply.
06:42Roots go deeper into the soil in search of nutrients, water and air.
06:50Air and water supply.
06:53Soil acts as a reservoir of water and air.
06:59Plant absorbs water through their roots.
07:02From this reservoir, roots breathe in oxygen from the air stored in soil mass.
07:09Heat or warmth of the soil helps in rapid decomposition of litter, thus enable faster
07:18release of nutrients.
07:22The soil also stores the sun heat and supplies it to the growing plants.
07:30Soil is necessary for producing many things, almost everything that we use in our daily
07:36lives.
07:38All the fruits, vegetables that we eat, which are all supported by soil.
07:45Even the clothes we wear.
07:48Most of the clothes we wear comes from cotton and the cotton comes from cotton plants and
07:53cotton plants are grown in soil.
07:57So many baskets, carry bags are made up of jute and jute too grows in soil.
08:06Erasers you use comes from rubber and rubber too comes from a tree that grows in soil.
08:16The tea we drink comes from tea leaves, so it's too a plant that grows in soil.
08:24The milk we drink comes from a cow and what does this cow eat?
08:29It eats grass, which too is a plant supported by soil.
08:36So there is no end to the uses of soil.
08:40So kids, today we learned a lot about soil.
08:44Now you may go ahead and take a quiz to learn more.
08:48Bye bye!