WOLKITE UNIVERSITY

COLLEGE OF ENGINEERING AND TECHNOLOGY

HYDRAULIC AND WATER RESOURCES
ENGINEERING DEPARTMENT
5TH YEAR 2ND SEMESTER
WATERSHED MANAGEMENT (HWRE5174)
GROUP 3
GROUP NAME………………………………….ID NO
1. TULU ADUGNA……………………………. NSR/1483/12
2. ALEMU CHKSA……………………………. NSR/1752/12
3. TEMESGEN YILKAL…………………….…. NSR/1402/12
4. BEDASA DANIEL…...………………………. NSR/0248/12
5. GETAHUN TUKA………………………….... NSR/0666/12

SUBMITTED TO:
MR. MEZEN D.
SUBMISSION DATE
02~07~2016 E.C
 Table of Contents
Table of Figure ................................................................................................................................ 1
INTRODUCTION......................................................................................................................... 2
1. SOIL EROSION CONTROLLING MEASURES (AGRONOMIC) ................................... 3
1.1. Components ............................................................................................................................ 3
1.2. Introduction for each component of Agronomic measures .................................................. 3
1.3. Suitable area of each component of Agronomic measures .................................................. 7
1.4. Design criteria for each component of Agronomic measures .............................................. 8
1.5. Limitations each component of Agronomic measures ......................................................... 8
1.6. Sample layout each component of Agronomic measures ................................................... 9
2. SOIL EROSION CONTROLLING MEASURES IN LAND MANAGEMENT .................... 10
2.1. Components Soil Erosion Controlling Measures of Land Management............................ 10
2.3. Suitable area component of Soil Erosion Controlling Measures by Land Management ... 11
2.4. Design criteria for each component Soil Erosion Controlling Measures by Land
Management .............................................................................................................................. 12
2.5. Limitations of Soil Erosion Controlling Measures by Land Management ........................ 12
2.6. Sample layout Soil Erosion Controlling Measures by Land Management ........................ 12
3. SOIL EROSION CONTROLLING MEASURES (MECHANICAL/STRUCTURAL MEASURES) . 13
3.1. Components of soil erosion controlling measures by mechanical ..................................... 13
3.2. Introduction for each component of soil erosion controlling measures by mechanical ..... 13
3.3. Suitable area of each component of soil erosion controlling measures by mechanical ..... 14
3.4. Design criteria for each component of soil erosion controlling measures by mechanical
................................................................................................................................................... 14
3.5. Limitations of soil erosion controlling measures by mechanical ....................................... 14
3.6. Sample layout of soil erosion controlling measures by mechanical .................................. 14
CONCLUSION ............................................................................................................................. 15
REFERENCE ................................................................................................................................ 16

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 Table of Figure

Figure 1.1 Cover Crops ................................................................................................................... 4

Figure 1.2 Crop Rotation ................................................................................................................ 4
Figure 1.3 Agroforestry .................................................................................................................. 5
Figure 1.4 Conservation Tillage ..................................................................................................... 5
Figure 1.5 Mulching........................................................................................................................ 6
Figure 1.6 Mixed/Intercropping ...................................................................................................... 6
Figure 1.7 Strip cropping ................................................................................................................ 7
Figure 2.1 contour plowing ........................................................................................................... 10
Figure 2.2 Terracing...................................................................................................................... 11
Figure 2.3 Strip Cropping ............................................................................................................. 11
Figure 3.1 Silt Fences ................................................................................................................... 13
Figure 3.2 Check Dam .................................................................................................................. 14

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 INTRODUCTION

Majority of the population in Ethiopia is relying on agriculture for their survival. In Ethiopia, the
problem of land degradation especially soil erosion and depletion of nutrients is a critical
environmental crisis. Most of the cultivated lands are slopping and require one or more types of
soil and water conservation measures. The topography and agro-climatic conditions are also
varying; that one should have the ability to discern what type of soil and water conservation
measures a particular land area requires. Most of the cultivated land needs application of long-
term soil and water conservation measures followed by reorganization of land use pattern
efficiently including soil moisture conservation, improvement of soil productivity and cropping
and farming systems.

There are different ways of conserving soil and water. Generally, they are mechanical, biological
and agronomic soil and water conservation Soil erosion is a serious environmental issue that
affects the productivity of agricultural lands and the quality of water resources. It is caused by
various factors, including water, wind, and human activities. To combat soil erosion, several
controlling measures have been developed, which can be categorized into three main groups:
agronomic measures, land management practices, and mechanical/structural measures.

Soil can be defined as the organic and inorganic material on the earth’s surface resulting from the
interaction between atmospheric agents and biological activity in the original material or in the
underlying hard rock. Soil provides a physical medium for plant growth. Soil erosion is a naturally
occurring process that affects all landforms. The causes and effects should be studied in order to
control soil erosion. Erosion, whether it is by water, wind or tillage, involves three distinct actions,
soil detachment, movement and deposition.

Decision-making in soil erosion control depends on factors like the soil type, topography, or
climate specifics, and applied agricultural practices like tillage system or crop rotation. Success
starts with early problem detection and the choice of suitable methods depending on its severity.
For example, replanting, cover crops, or mulching can be good ways to reduce soil erosion in the
initial stages because vegetation protects fields from destruction by water run-offs, raindrops, and
wind.

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1. SOIL EROSION CONTROLLING MEASURES (AGRONOMIC)

Soil erosion is a significant environmental issue that can lead to the loss of fertile topsoil, decreased
agricultural productivity, and increased sedimentation in water bodies. Agronomic measures play
a crucial role in controlling soil erosion by implementing practices that focus on managing
vegetation cover, reducing runoff, and promoting soil conservation to control soil erosion
effectively. By utilizing various agronomic practices, it is possible to mitigate the impact of erosion
and preserve the quality of soil for sustainable agriculture( Misebo et al., 2018).

1.1. Components

 Cover Crops
 Crop Rotation
 Agroforestry
 Mulching
 Conservation Tillage
 Strip Cropping
 Mixed/Intercropping

1.2. Introduction for each component of Agronomic measures

Cover Crops: Cover crops are plants grown to protect and improve the soil when the primary crop
is not growing. They help prevent erosion by covering the soil surface and reducing water runoff.
Components of Common cover crops include legumes, grasses, and brassicas. The choice of cover
crop will depend on the specific conditions of the site, including climate, soil type, and cropping
system( Asfaw, 2022).
Major role of plant cover is to protect the soil from the force of falling raindrops which is the
primary cause of erosion on cultivated land. Erosion from cultivated fields can be reduced if the
land has enough crop canopy during the peak season. Good ground cover canopy gives protection
to the land like an umbrella. Cover crop is a close growing crop raised mainly for protection and
maintenance of soil.

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  Figure 1.1 Cover Crops
Crop Rotation: Crop rotation involves planting different crops in a particular order over time on
the same piece of land. This practice helps maintain soil health, reduce erosion, and manage pests
and diseases. Growing of crops in an order in which the chosen cultivated crops follow one another
in a set cycle on some field over a definite period for their growth and maturity with an objective
to get maximum profit from least investment without impairing soil fertility. A good rotation
should include a cultivated row crop densely planted, small grain and a spreading legume.

 Figure 1.2 Crop Rotation

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Agroforestry: Agroforestry integrates trees and shrubs into agricultural systems. Trees help
stabilize the soil, reduce wind erosion, and enhance biodiversity. It refers to a system of land uses in
that there are different trees or shrubs are grown in association with different agricultural crops, pastures or
livestock.

 Figure 1.3 Agroforestry

Conservation Tillage: Is any method of soil cultivation that leaves the previous year's crop residue on
fields before and after planting the next crop to reduce soil erosion and runoff, as well as other benefits such
as carbon sequestration.

 Figure 1.4 Conservation Tillage

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Mulching: is the practice of covering the soil surface with a layer of organic or inorganic material.
This layer helps to protect the soil from erosion by reducing the impact of raindrops and runoff,
and promoting infiltration. Components of Organic mulches can include straw, leaves, wood chips,
or compost. Inorganic mulches can include gravel, stones, or plastic sheets.

 Figure 1.5 Mulching

Mixed/Intercropping: Intercropping is the cultivation of two or more crops at the same time in the same
field. A wide range of crops can be used for intercropping. Mixed cropping of different crops along with
the main crops, such as millets and different legumes, is an insurance against the climate change. The
different root systems of mixed crop feed at different depths of the soil. Moreover, mixing cropping
provides small quantities of a grain of different kinds of home consumption at different times.

 Figure 1.6 Mixed/Intercropping

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Strip Cropping: 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 checks the surface runoff
and forces them to infiltrate into the soil, which facilitates the concentration of rainwater.

 Figure 1.7 Strip cropping

1.3. Suitable area of each component of Agronomic measures

Cover Crops: Suitable for areas with sloping terrain or exposed soil vulnerable to erosion.
Are suitable for any area where there is a gap between primary crop growth periods. They are
particularly beneficial on slopes and areas with low vegetative cover.
Crop Rotation: Applicable in various agricultural settings to maintain soil fertility and structure.
Agroforestry: Ideal for regions prone to erosion, where trees can provide windbreaks and stabilize
the soil.
Mulching: is suitable for slopes, areas with low vegetative cover, and areas prone to heavy rainfall.
Strip Cropping: Strip cropping is a farming technique used to control soil erosion by planting
different crops in alternating strips across a field. Suitable areas for strip cropping include:
 Sloping Lands
 High Rainfall Areas
 Areas with Vulnerable Soil Types

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1.4. Design criteria for each component of Agronomic measures

Cover Crops: Select cover crops based on their ability to establish quickly, provide ground cover,
and have deep root systems. Cover crops should be planted at a high enough density to effectively
cover the soil surface. They should be selected based on their ability to suppress weeds, fix
nitrogen, and promote soil health.
Crop Rotation: Plan crop sequences that complement each other in terms of nutrient uptake, pest
management, and soil conservation.
Agroforestry: Choose tree species that are well-adapted to the local climate, have deep roots, and
can enhance soil structure.
Mulching: The thickness of the mulch layer should be at least 5 cm for effective erosion control.
The mulch should be applied evenly over the entire area to be protected.
Strip Cropping: When designing a strip cropping system for soil erosion control, several criteria
need to be considered:
 Crop Selection
 Strip Width and Orientation
 Spacing between Strips

1.5. Limitations each component of Agronomic measures

Cover Crops: May require additional labor, time and resources for planting, management, and
termination. They may also compete with the primary crop for water and nutrients if not managed
properly.
Crop Rotation: Success depends on proper planning and knowledge of crop compatibility.
Agroforestry: Initial establishment costs and competition with crops for resources can be
challenges.
Mulching: Organic mulches can break down over time, requiring regular replenishment. Inorganic
mulches can be more expensive and may not provide the same benefits for soil health as organic
mulches.
Strip Cropping: While strip cropping is an effective method for controlling soil erosion, it also
has some limitations:
 Yield Reduction

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  Management Complexity
 Suitability for Large-Scale Farms

1.6. Sample layout each component of Agronomic measures

Cover Crops Layout: Alternating rows of primary cash crops with cover crops like legumes or
grasses.
Crop Rotation Layout: Dividing fields into sections for different crop types each season.
Agroforestry Layout: Intercropping rows of trees with agricultural crops to maximize land use
efficiency.
Mulching layout: Mulching is a uniform application over the entire area.
Strip Cropping layout: A sample layout of a strip cropping system for soil erosion control may
include alternating strips of grasses and cash crops across a sloping field. The strips should be
narrow, perpendicular to the slope, and properly spaced to maximize erosion control benefits.

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2. SOIL EROSION CONTROLLING MEASURES IN LAND MANAGEMENT

Soil erosion is a significant environmental issue that can have detrimental effects on agriculture,
ecosystems, and water quality. Implementing effective soil erosion control measures is crucial to
mitigate these impacts and maintain soil health. There are various components involved in soil
erosion control measures, each with specific introductions, suitable areas, design criteria,
limitations, and sample layouts(Bulletin, n.d.).

2.1. Components Soil Erosion Controlling Measures of Land Management

 Contour Plowing
 Terracing
 Strip Cropping
2.2. Introduction for each component:
Contour Plowing: Plowing along the contour lines of the land helps slow down water runoff,
reducing erosion.

 Figure 2.1 contour plowing

Terracing: Building terraces or steps on slopes helps create flat areas that reduce water flow
velocity and prevent soil movement. Terraces can be constructed using a variety of materials,
including earth, rock, concrete, or masonry. Terracing is the practice of creating level platforms or
steps on a slope to reduce the length and steepness of the slope, thereby reducing runoff and
erosion. Terraces can also improve water management and increase agricultural productivity.

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  Figure 2.2 Terracing
Strip Cropping: Planting different crops in alternating strips across a field helps break up
potential pathways for erosion.

 Figure 2.3 Strip Cropping

2.3. Suitable area component of Soil Erosion Controlling Measures by Land

Management

Contour Plowing: Effective on hilly or sloping terrain prone to water erosion.

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Terracing: Suitable for steep slopes where water runoff is a significant concern. Terracing is
suitable for steep slopes with moderate to high rainfall levels. It is commonly used in agriculture,
forestry, and landscaping applications.
Strip Cropping: Beneficial in areas with moderate slopes and varying soil types.

2.4. Design criteria for each component Soil Erosion Controlling Measures by
Land Management

Contour Plowing: Maintain consistent plowing depth along contour lines to create water retention
basins.
Terracing: Construct terraces at appropriate intervals based on slope steepness to control water
flow.
Strip Cropping: Plan crop strip widths and arrangements to maximize erosion control benefits.

2.5. Limitations of Soil Erosion Controlling Measures by Land Management

Contour Plowing: Requires skillful implementation to ensure proper contour alignment.
Terracing: Initial construction costs can be high (expensive), especially on larger slopes and time-
consuming to construct.
Strip Cropping: Effectiveness may vary depending on crop selection and field layout.

2.6. Sample layout Soil Erosion Controlling Measures by Land Management

Contour Plowing Layout: Parallel plow lines following the natural contours of the land.
Terracing Layout: Stepped terraces built across a slope with retaining walls or embankments.
Strip Cropping Layout: Alternating strips of corn and soybeans across a field to disrupt erosion
pathways.

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3. SOIL EROSION CONTROLLING MEASURES (MECHANICAL/STRUCTURAL
MEASURES)

Soil erosion is a significant environmental issue that can have detrimental effects on agriculture,
infrastructure, and ecosystems. Mechanical and structural measures are essential in controlling soil
erosion by physically preventing the movement of soil particles(Publishers, n.d.).

3.1. Components of soil erosion controlling measures by mechanical

 Silt Fences
 Check Dams
 Retaining Walls

3.2. Introduction for each component of soil erosion controlling measures by mechanical

Silt Fences: Permeable barriers installed along slopes to trap sediment carried by runoff water.

 Figure 3.1 Silt Fences

Check Dams: Small structures placed in drainage channels to slow down water flow and reduce
erosion.

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  Figure 3.2 Check Dam
Retaining Walls: Vertical structures built to hold back soil on steep slopes or hillsides.
3.3. Suitable area of each component of soil erosion controlling measures by mechanical
Silt Fences: Effective in construction sites or areas with exposed soils near water bodies.
Check Dams: Suitable for gullies, ditches, or small streams experiencing erosion issues.
Retaining Walls: Ideal for stabilizing steep embankments or preventing landslides.

3.4. Design criteria for each component of soil erosion controlling measures by
mechanical

Silt Fences: Install at appropriate distances along slopes based on soil type and slope gradient.
Check Dams: Construct at intervals that allow for sediment deposition without causing overflow.
Retaining Walls: Design walls with proper drainage systems to prevent water buildup behind
them.

3.5. Limitations of soil erosion controlling measures by mechanical

Silt Fences: Regular maintenance is required to prevent clogging and ensure effectiveness.
Check Dams: May require periodic sediment removal to maintain functionality.
Retaining Walls: Costly construction and potential issues with drainage if not designed correctly.

3.6. Sample layout of soil erosion controlling measures by mechanical

Silt Fences Layout: Parallel installation along the base of slopes or around construction sites
Check Dams Layout: Strategically placed in gullies or channels at intervals
Retaining Walls Layout: Vertically constructed along steep slopes or hillsides

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 CONCLUSION

Soil erosion is a critical environmental issue in Ethiopia, especially in agricultural areas.

Implementing effective soil erosion control measures is essential to protect the soil, maintain
agricultural productivity, and preserve water resources. The controlling measures can be
categorized into agronomic measures, land management practices, and mechanical/structural
measures. Erosion is the loss of soil. As soil erodes, it loses nutrients, clogs rivers with dirt, and eventually
turns the area into a desert. Although erosion happens naturally, human activities can make it much worse.
Erosion can turn once healthy, vibrant land into arid, lifeless terrain and further cause landslides and
mudslides. Erosion can be controlled easily on a construction site when the right means, tools, and methods
are used at the right time. The most natural and effective way to prevent erosion control is by planting
vegetation.

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 REFERENCE

Asfaw, A. (2022). Review on the role of soil and water conservation practices on soil properties
improvement in Ethiopia. 8, 225–231.
Bulletin, F. A. O. S. (n.d.). Soil conservation and management in developing countries. FAO Soils
Bulletin (FAO), no. 33.
Misebo, A. M., Dawa, D., Box, P. O., & Dawa, D. (2018). The Role of Agronomic Practices on
Soil and Water Conservation in Ethiopia ; Implication for Climate Change Adaptation : A
Review. 10(6), 227–237. https://doi.org/10.5539/jas.v10n6p227
Publishers, C. (n.d.). Soil and Water Conservation Practices and its Contribution to Small Holder
Farmers Livelihoods in Northwest Ethiopia : A Shifting Syndrome from Natural Resources
Rich Areas. https://doi.org/10.31031/MCDA.2019.03.000574

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