The document discusses the history and distribution of soil erosion globally and in India. It describes common forms of soil erosion such as water erosion, wind erosion, and mass movement. Key indicators for identifying soil erosion are mentioned, such as eroded soil, gullies, sedimentation, and loss of topsoil. The impacts of soil erosion include reduced soil fertility, increased flooding, and water pollution. Strategies to control erosion include terracing, contour plowing, cover cropping, check dams, and reforestation.

1. UNIVERSITY OF AGRICULTURAL SCIENCES
DEPARTMENT OF SOIL SCIENCE AND AGRIL. CHEMISTRY
COLLEGE OF AGRICULTURE
G.K.V.K, BENGALURU- 560065
SOIL EROSION

2. Flow of Presentation:
1. History of soil erosion
2. Distribution
3. Identification and description of soil erosion problems in India
4. Forms of soil erosion
5. Impact of soil erosion on-site and off-site effects
6. Strategies for erosion control and conservation

3. 1. History
❑ Soil erosion is a natural geological
process that has been occurring for millions
of years. It involves the removal and
transportation of soil by various agents
like water, wind, ice, and gravity.
❑ The history of soil erosion can be traced
back to the early stages of Earth's
formation, where natural forces like
rainfall and wind have been eroding the
soil. Ancient civilizations also experienced
soil erosion, but their impact was localized
and relatively limited compared to modern
times.

4. The history of accelerated soil erosion due to human activities
can be divided into several key periods:
1. Prehistoric and Ancient Times
2. Civilization
3. Middle Ages
4. Colonial Era
5. Industrial Revolution
6. Modern Era

5. 1. Prehistoric and Ancient Times:
❖ Even in prehistoric times, early human
societies began practicing agriculture, which
involved clearing land for cultivation. This
led to some degree of soil erosion, but the
effects were relatively minor compared to later
periods.

6. 2. Civilization
❖ As civilizations developed and
expanded, agricultural practices
intensified, and deforestation became
more common.
❖ In Mesopotamia, ancient Greece, and
Rome, widespread soil erosion
occurred due to unsustainable land use
practices, contributing to the decline of
some civilizations.

7. 3. Middle Ages
• During the Middle Ages, soil erosion
continued to be a significant problem,
particularly in Europe. The expansion
of agriculture, coupled with
inappropriate land management,
resulted in extensive soil degradation.

8. 4. Colonial Era:
• The period of European
exploration and colonization
in the 15th to 19th centuries
brought significant land use
changes and increased soil
erosion in various parts of the
world. The introduction of new
crops, overgrazing, and large-
scale land clearing caused
substantial environmental
degradation.

9. 5. Industrial Revolution
➢ starting in the late 19th century, brought
about technological advancements, which
further intensified soil erosion. The
increased use of machinery and
industrial agriculture practices
exacerbated the problem.

10. 6. Modern Era:
• The 20th century witnessed rapid
population growth, urbanization, and
industrialization, leading to even more
widespread soil erosion. Large-scale
deforestation, construction of roads
and infrastructure, and improper
agricultural techniques accelerated soil
degradation on a global scale.

11. 2. Distribution of soil erosion in the world
✓ Africa: Many regions in Africa, such as the Sahel, experience
severe soil erosion due to factors like deforestation,
overgrazing, and unsustainable agricultural practices.
✓ Asia: In several Asian countries, soil erosion is a significant
problem. Countries like China, Indonesia and the Philippines
face extensive erosion due to deforestation, intensive
agriculture, and rapid urbanization.
✓ South America: Countries in South America, particularly
Brazil and Argentina, have significant issues with soil erosion,
primarily caused by deforestation for agriculture and
livestock grazing.
✓ North America: In the United States and Canada, soil erosion
is a concern in various agricultural regions, especially where
intensive farming practices are prevalent.
✓ Australia: Soil erosion is a significant issue in Australia,
particularly in areas with low vegetation cover and arid
climates.

12. Distribution of soil erosion in India
✓ Distribution of Soil Erosion in India:
✓ India faces substantial soil erosion
problems, with different regions
experiencing varying levels of erosion.
Some of the factors contributing to soil
erosion in India include deforestation,
improper land use practices, overgrazing,
and monsoon rains. Here's a general
overview of soil erosion distribution in
India:

13. ❑ Northern Plains: The fertile Indo-Gangetic plains
experience moderate to severe soil erosion, mainly due to
intensive agriculture and inadequate land management
practices.
❑ Western and Central India: The regions in the western and
central parts of India, including states like Maharashtra,
Madhya Pradesh, and Gujarat, face significant soil
erosion problems, partly due to deforestation and hilly
terrain.
❑ Eastern India: States like Odisha, Jharkhand, and parts
of West Bengal have high soil erosion rates, attributed to
deforestation, mining, and improper land use practices.
❑ Northeastern India: The northeastern states experience
varying degrees of soil erosion, driven by factors like
deforestation, shifting cultivation, and heavy monsoon
rains.
❑ Southern India: Some regions in Southern India,
particularly in Kerala and Tamil Nadu, have moderate soil
erosion issues related to agricultural practices and
deforestation.

14. Area affected by soil erosion in the world and in India
➢ World:
Surface area: 510.1 million km²
Land area: 148.9 million km²
Soil erosion rate: 2.4 t/ha/yr
➢ India:
Surface area: 328.72 m.ha.
Cultivable land area: 130 m. ha.
Soil erosion rate:10 t/ha/yr

16. 3. Identification and description of soil erosion problems in
India
Identifying soil erosion involves
recognizing its signs and symptoms on
the land. Here are some key indicators
and methods to identify soil erosion:
❑ Eroded Soil: The presence of eroded
soil, such as sediment deposits or
sand and silt accumulation in rivers,
streams, and low-lying areas, is a
clear sign of soil erosion.

17. ❑ Gullies and Rills:
Gullies are deep, narrow channels formed
by concentrated water flow, while rills are
smaller and shallower. The presence of
gullies and rills on hillslopes and agricultural
lands indicates water erosion.

18. ❑ Sedimentation:
Sediment deposition in water bodies, such
as rivers, lakes, and reservoirs, is an
indication of soil erosion upstream.

19. ❑ Loss of Topsoil:
Soil erosion often results in the loss of the
topsoil, which is darker, nutrient-rich,
and critical for plant growth. The
exposure of subsoil or rocks is a sign of
severe erosion.

20. ❑ Sheet Erosion:
Sheet erosion occurs when water flows
over the surface in a thin, even layer,
removing the topsoil uniformly.
It may not be as visible as gullies but
leads to significant soil loss over time.

21. ❑ Bare Soil:
Areas with exposed and bare soil, devoid
of vegetation cover, are more susceptible to
erosion by wind and water.

22. ❑ Changes in Landform:
Soil erosion can alter the landscape,
resulting in changes in the contour of
hillslopes and the formation of terraces or
dunes.

23. ❑ Loss of Productivity:
Eroded lands often experience reduced
agricultural productivity due to the loss
of fertile topsoil and changes in soil
structure.

24. ❑ Soil Cracks:
Cracks and fissures in the soil surface
are signs of soil drying and compaction,
indicating vulnerability to erosion.

25. ❑ Erosion-Induced Loss of
Nutrients:
Soil erosion can lead to the loss of
essential nutrients like nitrogen,
phosphorus, and organic matter,
affecting soil fertility.

26. To identify and describe soil erosion accurately, various
methods and techniques are employed, such as:
❖ Erosion Plots:
❖ Remote Sensing:
❖ Erosion Models:
❖ Soil Erosion Surveys:

27. 1. Erosion Plots: Small plots are set up in areas of interest, and erosion rates
are measured over time by analyzing sediment collected in traps.

28. 2. Remote Sensing:
Satellite imagery and aerial photographs are used to detect changes in land cover
and landform, allowing for the assessment of erosion patterns over large areas.

29. 3. Erosion Models
Mathematical models, like the Universal Soil Loss Equation
(USLE) and Revised Universal Soil Loss Equation (RUSLE), are
used to estimate erosion rates based on factors like rainfall, soil
type, slope, and land use.

30. 4. Soil Erosion Surveys:
Field surveys and on-site assessments are conducted to evaluate erosion features,
sediment deposition, and land use practices.

31. 4. Soil erosion can take various forms depending on the erosive
agents and land conditions. The major forms of soil erosion are:
1. Water Erosion:
a. Sheet Erosion: Water flows over the soil surface in a thin, uniform layer,
removing the topsoil gradually. This form of erosion is often hard to detect
but can cause substantial soil loss over time.
b. Rill Erosion: The concentration of water flow results in the formation of small,
shallow channels called rills on hillslopes and agricultural lands.
c. Gully Erosion: Gullies are deeper and wider channels formed by concentrated
and rapid water flow. They can significantly reshape the landscape and lead
to severe soil loss.

33. 2. Wind Erosion:
a. Suspension: Fine soil particles are lifted by the
wind and carried over long distances before
settling elsewhere.(<0.2mm)
b. Saltation: Larger soil particles are bounced along
the ground surface by the wind, causing
them to collide with other particles and move
in a hopping motion.(0.05-0.5mm)
c. Creep: Larger soil particles are moved along the
ground surface through a rolling or sliding
motion due to wind action.(>0.5mm)

35. 3. Glacier Erosion
Glaciers can erode the land as they advance and retreat, carrying away rocks and
soil, and leaving behind glacial valleys and moraines.

36. 4. Mass Movement Erosion:
a. Landslides:
The rapid movement of soil and rock down a slope, often triggered by heavy
rainfall, earthquakes, or human activities.

37. b. Mudflows:
Rapid flows of saturated soil and water, usually occurring in areas with steep
terrain and heavy rainfall.

38. 5. Coastal Erosion:
a. Beach Erosion: The wearing away of beaches by wave action and currents of
tides, resulting in the loss of coastal land.

39. b. Cliff Erosion:
The erosion of cliffs due to wave action, causing them to recede over time.

40. 6. Human-Induced Erosion:
a. Anthropogenic Erosion: Soil erosion caused or intensified by human activities,
such as deforestation, construction, agriculture, mining, and improper land
management.

41. 5. Impact of Soil erosion on-site and off-site
Soil erosion can have significant impacts both on-site (locally) and off-site (distant)
in terms of environmental, economic, and social consequences. Understanding
these effects is crucial for implementing effective soil conservation and land
management strategies.

42. On-Site Effects of Soil Erosion:
✓ Loss of Topsoil: Soil erosion removes the fertile top layer of soil, which is rich in nutrients and
essential for plant growth. The loss of topsoil reduces soil productivity and agricultural yields.
✓ Reduced Soil Fertility: Erosion leads to the loss of nutrients, organic matter, and soil
structure, affecting the soil's ability to support healthy plant growth.
✓ Lower Water Holding Capacity: Eroded soils have reduced water-holding capacity, making
them more susceptible to drought and affecting water availability for plants.
✓ Altered Soil Structure: Erosion disrupts the natural soil structure, making it more compacted
and less permeable, leading to increased surface runoff and reduced water infiltration.
✓ Increased Flooding: Soil erosion contributes to increased surface runoff, which can lead to
localized flooding and the loss of topsoil, crops, and infrastructure.
✓ Landslides and Gully Formation: Severe erosion can result in the formation of gullies and
landslides, causing extensive damage to landscapes, structures, and ecosystems.

43. Off-Site Effects of Soil Erosion:
❖ Sedimentation: Eroded soil particles are carried by runoff and wind to rivers, lakes, and reservoirs,
leading to sedimentation. This reduces water quality, damages aquatic habitats, and affects the
functioning of dams and reservoirs.
❖ Water Pollution: Sediment and associated nutrients, pesticides, and chemicals from eroded soil can
cause water pollution, harming aquatic life and affecting human health.
❖ Decreased River and Stream Capacity: Sediment deposition in water bodies reduces their capacity to
carry water, leading to increased flood risk and reduced water flow during dry periods.
❖ Loss of Biodiversity: Soil erosion can lead to habitat loss and degradation, affecting biodiversity and
ecosystem functioning.
❖ Climate Change: Soil erosion can contribute to climate change by releasing stored carbon into the
atmosphere as eroded organic matter decomposes.
❖ Economic Losses: Soil erosion can result in economic losses through reduced agricultural productivity,
increased costs for sediment removal from water bodies, and damage to infrastructure and property.

44. 6. Strategies for erosion control and conservation
1. Terracing
2. Contour Ploughing
3. Conservation Tillage
4. Cover Cropping
5. Mulching
6. Agroforestry
7. Riparian Buffer Strips
8. Check Dams and Sediment Traps
9. Afforestation and Reforestation
10. Soil Erosion Modelling
11. Land Use Planning
12. Public Awareness and Education

45. 1. Terracing
Creating terraces on hilly or sloping lands helps to reduce the speed of water
runoff and erosion. Terraces form flat steps along the slope, allowing water to be
retained and absorbed by the soil, minimizing erosion.

46. 2. Contour Ploughing
Ploughing along the contour lines of the land instead of up and down the slope helps to
slow down water flow and prevent soil erosion. Contour plowing reduces the formation
of rills and gullies.

47. 3. Conservation Tillage
Adopting conservation tillage practices, such as no-till or reduced tillage, minimizes
soil disturbance and helps retain crop residues on the field. This reduces erosion and
preserves soil structure and organic matter.

48. 4. Cover Cropping
Planting cover crops, like grasses or legumes, during fallow periods or between main
crops, helps protect the soil from erosion by providing ground cover and improving
soil health.

49. 5. Mulching
Applying organic mulch, such as straw or wood chips, on the soil surface helps to
prevent water and wind erosion, reduce evaporation, and improve soil moisture
retention.

50. 6. Agroforestry
Integrating trees and shrubs with agricultural crops in agroforestry systems helps
stabilize soil, enhance biodiversity, and provide additional income through tree products.

51. 7. Riparian Buffer Strips
Planting vegetation along riverbanks and water bodies forms riparian buffer strips,
which reduce sediment and nutrient runoff into waterways, protecting water
quality and aquatic ecosystems.

52. 8. Check Dams and Sediment Traps
Constructing check dams and sediment traps in drainage channels helps retain
sediment and control water flow, reducing downstream erosion.

53. 9. Afforestation and Reforestation
Planting trees on degraded lands and deforested areas helps prevent soil erosion,
stabilize slopes, and promote carbon sequestration.

54. 10. Soil Erosion Modeling
Using erosion prediction models, such as the Universal Soil Loss Equation (USLE)
or Revised Universal Soil Loss Equation (RUSLE), can help identify erosion-
prone areas and guide the implementation of targeted erosion control measures.

55. 11. Land Use Planning
Implementing appropriate land use planning and zoning regulations can help
prevent soil erosion by restricting certain activities in vulnerable areas, such as steep
slopes or areas prone to flooding.

56. 12. Public Awareness and Education
Raising awareness among farmers, landowners, and communities about the
importance of soil conservation and providing information about erosion control
practices can encourage sustainable land management.

57. THANK YOU