Soil Erosion & conservation Hello everybody lets start with a new chapter called as soil erosion and conservation. In this chapter we will be talking about what is soil erosion, what are the various ways in which soil gets eroded and how we can conserve soil and prevent soil erosion Soil Erosion & conservation Part 1

Introduction The upper layer of the earth is mostly soil Soil provides minerals for plants to grow Soil is made up of small particles of broken down rock, remains of dead plants and animals, water and air Soil also has tiny living things called as bacteria The upper layer of the earth is made up of soil Soil is so important that it provides minerals for plants to grow Now when you see what soil is made up of, we see that it is made up of small particles of broken down rocks, dead and decaying plants and animals, water as well as air. Soil even has tiny living things called as bacteria. We know that soil is very important for us. Let us see how exactly we depend on soil and what all it provides us

Importance of soil Plants Animals Get nutrition from soil They are able to grow and make food Find shelter in soil. Eg: rabbits, ants, & earthworm We need products from soil to build our home

How is soil formed? Soil is formed by breaking down of rocks into small pieces- Weathering of rocks Animals, roots of plants, rain, force of flowing water, and wind & weather changes help to break down rocks into smaller pieces Moving water carries rocks, these knock against each other and break into smaller pebbles which finally breaks into tiny grain of sand When rocks break down into smaller pieces soil is formed. This process is called as weathering of rocks Weathering is rocks happens because of animals, roots of plants that go deep into certain rocks, rain, force of flowing water, wind and weather changes. (Read 3)

Now let us look at soil erosion more in detail & how its caused

Soil erosion Soil forms and settles in layers. The topmost layer of the soil is called ‘topsoil’ Topsoil gets mixed with humus & is the fertile layer of the soil If the topsoil is removed by wind or water, fertility of the soil is lost and the land becomes barren and unfit for farming The removal of topsoil by wind or water is known as soil erosion The soil on earth when formed settles in layers In these layers the topmost layer is called as topsoil It is this topsoil that gets mixed with humus (organic material- dead and decaying animals and plants) because it mixes with humus it is the fertile part of soil If this topsoil is removed by wind and water then even the fertility of soil gets lost and the land becomes barren Barren: dry land where plants cannot grow

Different types of soil erosion Erosion by water Erosion by wind Erosion due to human activity

Erosion by water Flowing rain water carries a part of the soil Soil erosion by water is greater in hilly regions At planes flow of river slows down and deposits soil This causes rivers to change course and which results in floods As rain water flows on land, it takes a part of soil with it. This results in soil erosion (read point 2) As water flows with more and more speed as it comes down hill it erodes more and more soil from uphill. (read point 3) Over the years as these deposits increase, rivers change course, which even results in floods, causing heavy loss of life and property

Erosion by wind Strong winds cause top soil to be blown away. Wind erosion is greatest in dry areas particularly in deserts. (Read point 1) especially in areas where there is less vegetation to bind soil. This soil that is carried goes and deposits at a place where there is less wind speed. Read point 2

Erosion due to human activities Overgrazing Deforestation Roots of plants hold soil particles together and reduce erosion of soil by wind and water. However human activities have lead to the reduction in plant cover and caused an increase in soil erosion Deforestation: we have cleared forests to build farmlands, cities, roads and for our wood requirements. This leaves land bare and increases erosion. Even ploughing leaves soil loose Overgrazing: we rear cattle for our use, and when these cattle overgraze they expose the top soil by eating away all the plants growing on it, this increases soil erosion

recap The removal of topsoil by wind or water is known as soil erosion What is soil erosion? The removal of topsoil by wind or water is known as soil erosion Various ways in which soil gets eroded: Erosion by water Erosion by wind Erosion by human activities: Deforestation Overgrazing

So with this we come to the end of part 1 of soil erosion So with this we come to the end of part 1 of soil erosion. In the next part we will discuss how to conserve soil. Thank you! Thank you!

Soil Erosion & conservation Hello and welcome to part 2 of soil erosion and conservation. So in the previous part of the chapter we looked at what was soil erosion and what were the various ways in which soil is being eroded. Now in this part we will focus on how to conserve soil. Soil Erosion & conservation Part 2

Formation of just 1cm thick layer of soil takes more than 100 years, but it can all get eroded in just a few years leaving the land barren and unfit to farm. Therefore, it is very important to protect soil from erosion. So… # (read) Soil conservation The protection of soil against erosion is known as soil conservation.

afforestation Planting tress or afforestation is a very effective way of reducing soil erosion.# Grass grown on slopes in hilly areas prevents erosion of soil by water flowing down the slopes

Soil cover The next method is soil cover. After crop is harvested or before the next crop is sown, soil remains bare#. Now see this image and imagine what would happen if a strong wind blows or it rains heavily what would happen?? Soil will get eroded very easily by wind and water To prevent this farmers either grow grass(#) or cover their land with dried vegetation(#). This is called as soil cover

Windbreakers shelterbelts Growing hedges or trees along the edges of farmlands acts as wind breakers and reduces wind speed hence reduces erosion due to wind

Terrace/ step farming Along the slopes of hills, farming is done by cutting steps in slopes. This reduces the speed of water as it flows down. This reduces erosion by water. The soil eroded from one step deposits in the next step. So in this way no soil is lost.

Building embankments Rivers constantly erode soil on their banks. Strong embankments of rocks and soil are built along the edges of banks of rivers and lakes. These embankments are called as bunds. This also prevents the nearby land from getting flooded and protects it from soil erosion So with this we come to the end of the chapter! Lets do a quick recap

recap Soil conservation Types of Soil Conservation Afforestation The protection of soil against erosion is known as soil conservation. Types of Soil Conservation Afforestation Soil cover Shelterbelts Step farming Building embankments

Thank you!