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00:00Hi kids! Today we will learn about soil erosion. So let's start.
00:10Before we can learn what is soil erosion, first we should know how is soil formed.
00:19Soil is made up of organic and inorganic materials.
00:25Let's first see from where does this inorganic material come.
00:30Inorganic material in the soil comprises of minerals, salts, and particles of sand, clay, or silt.
00:40And we know whether it's sand, clay, or silt, all are rock particles.
00:49A lot of many forces like ocean waves, rain water, flow of rivers, growing of plant roots in the soil,
00:58breaks the small pieces of rocks that then becomes part of the soil.
01:03And this breaking of small pieces of rocks is called as weathering of rocks.
01:11Minerals and salts present in the soil also were once part of big rocks.
01:18They are dissolved by the forces of water and becomes part of the soil.
01:24So all the inorganic material in the soil comes from the weathering of rocks,
01:30that is breaking of small pieces of rocks.
01:34You know all plants need these minerals from soil to grow.
01:42Other component of soil is the organic material,
01:47which is the remains of living things like plant remains,
01:53fallen leaves, twigs, stems, throw away or fallen fruits and vegetables and seeds.
02:02Animal remains, dead animals small or big, dead insects or other animals.
02:10So remains of living things decay and become part of the soil.
02:17These organic remains forms nutrients that are required by plants to grow.
02:23So kids, soil is a mix of organic and inorganic material.
02:30And which is mainly formed by weathering of big or small rocks
02:35and decaying of dead plants and animal remains.
02:40Process of soil creation is very, very slow.
02:44It takes hundreds of years to make top layer of soil,
02:48which is fertile or supports plant growth.
02:52Now let's learn what is soil erosion.
02:57When the soil is subjected to natural and man-made forces
03:02that washes away the top fertile layer of soil,
03:06it is known as soil erosion.
03:09Soil erosion makes the soil unsuitable for cultivation.
03:15Loose and dry soil with no vegetation is more prone to soil erosion.
03:23As roots of the plants hold the soil firmly
03:27and hold it in place against the force of wind and water.
03:33So the land with no or less vegetation is more prone to soil erosion.
03:41Now let's learn some major factors responsible for soil erosion.
03:47Heavy winds and heavy rain leads to washing away
03:52of top layer of soil that leads to soil erosion.
03:58Human settlements and civilization.
04:02Humans, that is we, are the biggest factor responsible for soil erosion.
04:10Construction of new buildings, houses, roads and lakes
04:14leads to the damage of top layer of soil.
04:19Even some practices of farming or cultivation too
04:23damages the top layer of soil.
04:26Human needs are ever growing
04:28and new lands are being cleared up at an unprecedented rate
04:33to make more and more buildings,
04:35which is all leading to damage the top layer of the soil.
04:40Deforestation.
04:43Humans are cutting more and more trees for clearing land
04:47for their purposes like farming or making new buildings.
04:54Overgrazing.
04:56Animals grazing too leads to soil erosion
05:00as animals eat away the plants that protect soil from erosion.
05:05Gardening.
05:07Even we overwater our gardens and that too leads to soil erosion.
05:14Forest fires.
05:17Forest fires too lead to erosion of top soil.
05:21Overcropping.
05:23Repeatedly growing same crops on same land
05:27deplete the soil of its minerals and salts
05:31that make the soil infertile.
05:34Tilling of soil.
05:37Farmer removes all the plants from farm which is called tilling
05:42that makes the soil prone to erosion
05:45during rain and storms as there are no plants on land
05:50at that time to hold soil in place.
05:53Now let's see the effects of soil erosion.
05:57First of all, it degrades the quality of soil
06:01making it less fertile and not fertile at all.
06:06Causes huge loss to farmers
06:09as there is much less yield of crops from same land
06:13if its top layer is eroded.
06:16It harms human health.
06:19Eroded land is required to be added
06:22with a lot of chemical fertilizers in order to grow crops
06:27which ultimately becomes part of the crop and human diet
06:32and affects our health.
06:35Water with eroded soil and chemicals
06:38reaches water body and there too it pollutes the water body.
06:44It also has adverse effects on aquatic flora and fauna.
06:50The eroded soil ultimately reaches the water body
06:54and accumulates there leading to increase in water turbidity.
06:59An increased turbidity does not let much light enter the water
07:04and aquatic flora needs light for photosynthesis.
07:09Soil that reach water bodies is also rich in nutrients
07:15such as phosphorus and nitrogen
07:18which leads to excessive growth of algae.
07:22And algae decreases the amount of oxygen in water body
07:27that leads to death of aquatic fauna.
07:31Soil erosion also causes respiratory problems.
07:36Eroded soil with wind causes respiratory problems as we inhale it.
07:43Soil erosion harms the natural environment
07:47and we must try our best to protect the soil from soil erosion.
07:53And we will learn how we can prevent soil erosion in our next assignment.
08:00Now you may go ahead and take a quiz to learn more.
08:04Bye-bye.