A brief presentation on water erosion and its control measures.

1. Water Erosion Control Measures
Presented by-
SOUVIK GHOSH
Soil Science and Agricultural Chemistry
Uttar Banga Krishi Viswavidyalaya

2. Water erosion is the wearing away of the soil surface
by water from rain, runoff, snowmelt, and irrigation.
Water erosion control is the attempt to limit land
damage that is a result of erosion, which may occur
naturally from water.
Introduction

3. Different ways of control measures
(A) Mechanical Measures
1. Diversion drains
2. Terracing
3. Contour Bunding
4. Waterways
(B) Agronomical Measures
1. Contour farming
2. Strip cropping
3. Conservation tillage
4. Crop rotation and Mixed cropping
5. Mulching

4. (A) Mechanical Measures
1. Diversion drains
A diversion may be viewed as a channel constructed across the slope to conduct water to a safe
outlet.
It is constructed either to divert runoff from a hillside to a level bottom field or for diverting water
out of active gullies into a safe outlet. Diversions serve as the first line of defence.
Fig. 1.1: Structures of Diversion drains

5. 2. Terracing
Terracing is a method of erosion control accomplished by constructing broad channels across the slope of the
rolling land. A horizontal strip of length, either raised or more or less level, usually constructed on or nearly
on a contour is called the terrace. This is meant to decrease the length of the slope, thereby reducing soil
erosion and retaining runoff.
There are basically two
types of terraces:
(a) Broad base terraces
(b) Bench terraces
• The broad base terrace,
on the other hand, is
used to control and
retain surface water on
sloping land.
• The bench terrace,
perhaps one of the
oldest forms of terraces,
is used to reduce land
slope.
Fig. 1.3: Terracing
Fig. 1.2: Different types of Terracing

6. 3. Contour Bunding
Contour bund is the most common for soil and water conservation. It is constructed in regions having
less than 75 cm of annual rainfall; soil depth more than 20 cm; land slope less than 7% and good
infiltration capacity.
Contour bunds divide the length
of the slope, reduce the volume
of runoff water, and thus
preventing or minimising the soil
erosion.
Fig. 1.5: Contour BundingFig. 1.4: Structure of Contour Bunding

7. 4. Waterways
Waterways could be natural or man-made. Man-made waterways are most widely conservation measures
in high rainfall areas with large volume of runoff. Waterways can carry specified amount of water with
danger of serious erosion and serve as outlets for terraces, diversions and contour rows. The best loca-
tion for waterways is usually in a natural draw.
Fig. 1.6: Waterways Fig. 1.7: Cross-section diagram of waterways

8. (B) Agronomical Measures
1. Contour farming
Contour Cropping is a conservation farming method that is used on slopes to control soil losses due to
water erosion. Contour cropping involves planting crops across the slope instead of up and down the
slope.
Contour cropping is most effective on slopes between 2 and 10 percent.
Fig. 2.1: Contour farming

9. 2. Strip cropping
It is an important method which employs all the advanced cultivation practices such as contour
farming, proper tillage, crop rotation, mulching, cover cropping, etc. Strip cropping is very effective
and practical means for controlling soil erosion.
It is of the following types:
(a) Contour strip cropping,
(b) Field strip cropping,
(c) Wind strip cropping, and
(d) Permanent or temporary buffer strip cropping.
Fig. 2.3: Different structures of Strip croppingFig. 2.2: Strip cropping

10. 3. Conservation tillage
Conservation tillage is method of soil cultivation that leaves of the previous year’s crop residue (such
as corn stalks or wheat stubble) on fields before and after planting the next crop to reduce soil erosion
and runoff, as well as other benefits such as carbon store in soil.
Fig. 2.4: Zero tillage Fig. 2.5: Example of Conservation tillage

11. 4. Crop rotation and Mixed cropping
• Crop rotation is a method of growing a series of dissimilar crops in an area sequentially which helps
in the improvement of soil structure and fertility and thus water erosion is controlled.
• Mixed cropping is another important practice in which one main crop and one or two subsidiary
crops are grown together on the same land. This practice checks the soil erosion and avoids the
risk of crop failure. If one crop fails due to diseases or any other factor, the others remain ensured.
Fig. 2.6: Basic Crop rotation Fig. 2.7: Mixed cropping

12. 5. Mulching
It means covering the soil surface by straw, leaves or grasses. Mulches of different kinds check soil and
water erosion, increase soil fertility and also minimize moisture evaporation from the top soils. Various
types of surface tillers and crop residues are helpful in obstructing the movement of soil particles.
Fig. 2.8: Organic mulching Fig. 2.9: Plastic mulching

14. www.ecoursesonline.iasri.res.in
www.studyblue.com
www.milford.nserl.purdue.edu
www.fao.org
References

15. Thank You