its very crucial for short term training on soil erosion and conservation

1. መ ደ ወ ላ ቡ ዩ ኒ ቨ ር ሲ ቲ
MADDA WALABU UNIVERSITY
Soil Erosion and its Conservation
By: Kefa Feye
Venue: Bale-Goro, Ethiopia
June, 2023
Goro Mega Project
Short Term Training
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2. Introduction
Soil Erosion
SWC Measures
Presentation Outlines
Soil &Water Conservation
7/14/2023 Hawassa University 2
Conclusion

3. Introduction
 Soil is one the most fundamental and basic natural resources for all life to
survive
 Soil erosion by water, wind and tillage affects both agriculture and the
natural environment.
 Soil loss, and its associated impacts, is one of the most important
environmental problems.
 The threat of nuclear weapons and man's ability to destroy the
environment are really alarming.
 Soil erosion – is perhaps more dangerous still.

5. …..
Soil erosion is the main driver of land degradation in the area
Land degradation due to soil erosion is a serious threat and
seriously affects livelihoods and food security
High population pressure, improper land-use planning, over-
dependency on agriculture(source of livelihood) and
dependence on natural resources are inducing:
deforestation,
overgrazing,
expansion of agriculture to marginal lands and steep
slopes,
declining agricultural productivity

7. ……..
 Worldwide, an estimated 26 billion tons of topsoil are washed or
blown off cropland each year.
 Every year 6 million hectares of productive dry land become desert.
 Use land according to its capability and treat it according to its needs
by applying suitable scientific soil and water conservation measures
for maximum sustained production.
"A nation that destroys its soil destroys itself."

10. Soil Erosion
 Soil erosion is the removal of soil particles (including plant nutrients and organic
matter) from the place where they belong to elsewhere by either water or wind.
 It is one of the most chronic environmental and economic problems of the present
situation.
 It is getting worse than it was ever before.
 Hillsides stripped of their protective covering of vegetation are rapidly eroding,
 depositing huge amounts of silt into down stream reservoirs and river valleys.
 The wearing away of soil
 Loss of soil

11. ……..
 Broadly speaking, two types of soil erosion:
1. Geological/ Natural erosion:
 Includes soil-forming and soil Loss processes that maintain the soil in a
favorable balance;
 Responsible for the formation of the present topographic features;
2. Accelerated erosion:
 Human or animal induced erosion principally caused by human excessive
exploitation of natural resources;

12. ……..

13. …….

14. …….

15. Soil Erosion Types
Soil Erosion
Sheet Erosion Splash Erosion
Rill Erosion
Gully Erosion

16. ………..
Type of Soil Erosion:-
Splash erosion:
 Also called raindrop erosion.
 Involves soil detachment and transport resulting from the impact of water
drops;
 Severity of raindrop erosion very high on bare soils.
Sheet erosion:
 Uniform removal of soil in thin layers from sloping land by water.
 Sheet erosion can occur on any sloping land with low vegetative cover.
 Areas where loose, shallow topsoil overlies a tight sub-soil are most susceptible
to sheet erosion

17. ……
Rill erosion:
 Shallow channels created by runoff due to washing away of the surface soil.
 The channels can be removed by tillage.
Gully erosion:
 The severest type of erosion in which channels larger than rills produced.
 The channels carry water during and immediately after rains.
 Unlike rills, gullies cannot be obliterated by tillage.

18. Causes of soil erosion
 The major causes of soil erosion include the following:
 Poor management or inappropriate farming techniques,
 Livestock trampling,
 Removal of surface cover,
 Cultivation of steep slopes,
 Cultivation on river banks,
 Inappropriate road drainage, ….

19. Concept of Soil and Water Conservation
Soil and Water Conservation :
 is a set of management strategies for prevention of soil being eroded from the
earth’s surface or becoming chemically altered by
 overuse,
 acidification,
 salinization, or other chemical soil contamination.
 is the combination of different integrated approaches with four major disciplines
such as Forestry, Agronomy, Engineering and Soil Science
 is using and managing land based on the capabilities of the land itself.
 is defined as the application of Engineering or Biological Principles in farming
system on a small field or watershed scale as a remedy for Soil and Water
management problems.
 Ways to preserve (or save) the soil

20. …….
 The Primary purposes of soil and water conservation is to ensure sustainable
productivity of land through conservation of water resources and the prevention or
reduction of soil erosion, land slides and debris flow.
• The aim of conservation is to obtain the maximum sustained level of production by
maintaining soil loss below a threshold level (i.e., the natural rate of soil formation)
To protect the soil from erosion.
To keep required moisture content of Soil.
To maintain the productive capacity of the Soil.
To increase agricultural production, To minimize soil erosion
To overcome the shortage of animal feed
To make waste lands productive
 There are three Soil Conservation measures
Conservation Farming Soil Conservation measures
Biological Soil Conservation measures
Physical Soil Conservation measures

21. A. Conservation Farming Soil Conservation
 are Agronomic/ tillage practices and Soil Fertility management
deals used to :
• Control the velocity of surface runoff and .
• Land productivity enhancement measures
This category includes:
Soil Fertility Measures
 Composting,
 Green Manuring,
 Crop residue Management,
…
Tillage Practices
 Minimum/ Conservation
tillage,
 Zero Tillage,
Improved Farming Practices
 Contour cultivation
 Contour furrowing
 crop rotation,
 intercropping,
 strip cropping,
 mulching

22. B. Biological soil conservation measures
 are Organic and Living measures or vegetative barriers used to:
 increase biomass and
 Improve soil structure
Degraded Land and Gully area
rehabilitation measures
 Planting in Gullies,
 Area Closures
Afforestation Practices
 Enrichment planting
Agro-forestry
 Homestead planting
 On Farm-Forestry
(scattered, Boundary)

23. Improved Farming Practices
01
02
03
Crop rotation Cover Crops
Multiple cropping
 is the practice of growing
of two or more crops in the
same piece of land at
different time or calendar.
 is used to keep crops from
depleting the soil.
 If the same crop is planted
year after year, it exhausts
certain nutrients in the soil.
 are crops gown during off
season to protect the soil
from impacts of rain drop
and run off it could be a weed
or we can sow seeds of crops
or grasses.
 Plants which are grown to cover
the surface of the ground with
dense foliage, to control soil
erosion and improve the soil.
 is defined as growing of more
than one crop on the same
piece of land during one
blender year. It takes place in
different forms.
 Three main types of multiple
cropping, i.e.
 mixed cropping,
 relay cropping and
 sequential cropping.
.

24. Improved Farming Practices…..
04
05
06
Conservation Tillage
Mulching
Strip Cropping
 is an essential management
technique which provides a
suitable seed bed for plant
growth and helps to control
weeds.
 No-till and reduced-tillage farming
leaves old crop residue on the
ground instead of plowing it into soil.
This covers the soil, keeping it in
place.
 Merit of No Till Farming
 the ground is never broken,
 the crops are mowed,
 herbicides are added and
 seeds with fertilizers are directly
added to the soil.
 is the covering of the soil
with crop residues such
as straw, maize stalks, of
standing stubble.
 The cover protects the soil
from raindrop impact and
reduces the velocity of
runoff.
 It is a kind of agronomical
practice in which ordinary crops
are planted or grown in form of
relatively narrow strips across
the land slope.
 Strip cropping check the surface
runoff and forces them to
infiltrate in to the soil, which
facilitates to the concentration of
rain water.
 Types of strip cropping: Contour
strip cropping, Field strip
cropping, Buffer strip cropping.

25. Contour Plowing
Planting along contour lines of slopes helps reduce
erosion on hillsides.
Contour Plowing involves plowing grooves into the
desired farmland, then planting the crop furrows in
the grooves and following the contours.
It a very effective way for farmland on slopes to
prevent run off improve crop yields.

26. .
Windbreaks/Shelterbelts
 Strips of trees or tall grasses planted at appropriate
intervals to prevent or reduce wind erosion and crop
losses caused by wind.
 Rows of fast-growing trees around crop plantings
provide windbreaks, reducing erosion by wind
 Wind blowing in the same direction for a long time is
able to gain speed and therefore evaporate more
water from the soil and move more topsoil.
 A windbreak causes the wind to swirl and it
therefore does not cause as much damage.

27. C. Physical soil conservation measures
 are mechanical or structural engineering measures used to control the
velocity of surface runoff.
This category includes:
Moisture retention
structures
 like micro-basins,
 eye-brows,
 half moons,
 trenches etc,
Terrain re-Engineering
measures
 Bunds,
 Terraces,
Drainage structures
 Cutoff drains
 waterways
Gully Control measures
 check dams,
 sediment storage dams (SSD),

28. Terracing
 Terracing is used to control the runoff of
water in areas with steep slopes.
 The land is leveled in order to prevent
downhill runoff
 Cutting stair steps or terraces is the only
way to farm extremely steep hillsides
without causing massive erosion.
 It is labor-intensive to create, but has been
a mainstay for centuries.

30. Contour bunds:
 Contour bunds made of earth or stones or terraces that
consist of an excavated channel and a bank or ridge on the
downhill side for cultivatingcrops are permanent erosion
control technologies.
 The first are installed across slopes of low gradients, the
latter at right angles to the steepest slope in hilly areas.
 Contour bunds are earth banks, 1.5 to 2 m wide, thrown across
the slope to act as a barrier to runoff, to form a water storage
area on their upslope side and to break up a slope into segments
shorter in length than is required to generate overland flow.
A soil bund is a structural measure with an embankment of soil or
stones, or soil and stones, constructed along the contour and
stabilized with vegetative measures, such as grass and fodder
trees. The height of the bunds depends on the availability of
stones.

31. Bunds & Gullies

32. Check dams
 Check dams are structural measures serve as an obstruction wall across a
gully channel or a small stream.
 Check dams can be constructed in a wide range of conditions, such as:
 In small gullies or streams serving a larger one,
 As stone outlets for traditional or newly constructed bunds or
terraces unable to accommodate all run-off,
 As a silt trap for water ponds,
 As a retaining wall for sliding roadsides and canals,
 Check dams are mainly an aid to vegetative control measures

34. Check dam
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35. Gabion
 Gabions are rectangular boxes varying in size and are mostly made of
galvanized steel wire woven in to mesh.
 The boxes are tied together with wire and then field with stone and
placed as building blocks; This process is called Lacing
 Gabion boxes are commonly used in roadside protection or for
dam construction;
 Gabion check dams are built by placing the galvanized wire boxes
across gullies, “usually not higher than 1.5 m spillway height”

37. Green gold behind the Gabion check dam
Gully rehabilitated with Gabion check dam

38. Commonly stated benefits of SWC practices
 The use of SWC practices are more than stating;
 Reduces and stops the velocity of runoff;
 Trap water and allow it to percolate in to the ground (prevent
water from flowing down the slope)
 Prevent soil from erosion (gully formation etc)
 control loss of nutrients from agricultural land,
 Enhance the soil moisture
 prevent pollution of water bodies,
 decrease rate of sedimentation in reservoirs, rivers, canals
 prevent deterioration of land quality.

39. Conclusion
 Soil degradation particularly soil erosion is a very sensitive issue of
environmental damage and a worldwide problem.
 “Soil conservation is the prevention of soil loss from erosion or reduced fertility
caused by over usage, acidification, salinization or other chemical soil
contamination”
 Agronomical measures include contour farming, crop rotation, cover crop,
mulching, strip cropping and tillage practices to control the soil erosion.
 Mechanical or physical soil conservation measures include all practices and
structures, which involve earth moving and soil shaping methods in minimizing
soil erosion and water loss such as terraces, check dams, gabion.
 It is vital that good soil management is implemented to ensure high sustainable
production for economic viability and maintain or improve soil fertility.
Good soil stewardship, means food and
resources for the future

40. Thank you
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