Supplementary Notes

Question 2

Occurs when the conditions are favorable for the detachment and transportation of soil erosion material.

Answer 2

Soil erosion occurs

Question 3

What are the principles in reducing the susceptibility of the soil to erosion.

Answer 3

-limit detachment
-limit transportation
-reduce runoff, increase infiltration, roughen surface and reduce slope.

Question 4

Types of erosion control measures

Answer 4

• structural/mechanical methods
  -Biological/agronomic approach
  -Sloping agricultural land technology (SALT)

Question 5

-It traps sediments in the drainage ditches built along the terrace.
-generally needed on croplands that slope as much as 2%

Answer 5

Terracing

Question 6

-He slope is longer than 22 meters. In very absorptive soil, the terraces are built and water can stand and soak into the ground.
-Traditional practice in the Cordillera areas.

Answer 6

Terracing

Question 7

Construction of earthen embankment adjusted to soil and slope to control runoff. It is primarily designed to control runoff in areas of high rainfall and conservation of water in low rainfall areas.

Answer 7

Terracing

Question 8

-A shallow ditch that runs horizontally across the slope following the contour of the land.
-Constructed on farmland where the soil is reasonably deep.

Answer 8

Contour canals

Question 9

-Should be constructed on all slopes 5-25%.
-Should more or less be about 5 cm wide and 30 cm deep.

Answer 9

Contour canals

Question 10

-the main purpose is to hold water in a field, thereby increasing soil moisture and ground water supply and to drain water away from the field without necessarily changing the soil.

Answer 10

Contour canals

Question 11

-Small compartments of water can also help recharge groundwater aquifers.

Answer 11

Contour canals

Question 12

-they are more permanent structures that are built in areas with large rocks.
-Large rocks are used for the base and outside the wall, while smaller rocks are filled in the middle.

Answer 12

Contour rock walls

Question 13

-A-frame is made to use contour lines.
-A one-meter wide area is leveled to provide a good base for the wall.

Answer 13

Contour rock walls

Question 15

-usually 1 meter high, tapering slightly towards the top.
-Requires a great amount of labor.

Answer 15

Contour rock walls

Question 16

-use of large rectangular wire crates filled with stones acting as a retaining wall. These are flexible, absorbent, and economical in places where stones are abundant.

Answer 16

Gabions

Question 17

-Rocks fitted /piled on the top of each other to form a retaining wall.
-Protects soil from the impact of raindrops.

Answer 17

Riprap

Question 18

-Done by covering the whole area with a protective layer of concrete or rocks.
-Used to stabilize the hillside, road banks, and streams banks.
-The wall thickness may vary from ¼ to 1 meter.

Answer 18

Riprap

Question 19

-Involves the use of stones as wailing material.
-Stones are collected and piled along the contour to form high walls.

Answer 19

Stone walls

Question 20

-Depression on the farm, especially in heavily gullied areas.
-Can be utilized as farm ponds to store water and to minimize the potential runoff.

Answer 20

Farm ponds / Water Impounding Dams

Question 21

-Protects against drought.
-Improves food production (crops, fish, fruit trees, etc.)
-promotes conservation and ecological balance, easy to construct.

Answer 21

Farm Ponds / Water Impounding Dams

Question 22

-Simple structure that can stop gully erosion by slowing down the water flow in the drainage system.
-Promote the deposition of nutrient-rich, high fertile sediments.

Answer 22

Check Dams/Drop Weirs

Question 23

-Also barrier that stops the flow of water.
-Constructed when the grassed waterway is too long.

Answer 23

Check Dams / Drop Weirs

Question 24

This type of check Dam is constructed using concrete or solid masonry. Used in gullies or stream channels with high rates of runoff or where vegetation cannot be established.

Answer 24

Masonry Check Dam

Question 25

This type of check dam is rocks or stones are loosely piled up but with sufficient overlap to produce a single affect forming a check dam.

Answer 25

Rocks/Stone Check Dam

Question 26

This type of check dam use loose earth (clay materials) for check dam construction.

Answer 26

Earth Check Dam

Question 27

-This type of check dam uses poles or logs to check dam materials. - poles of logs are placed either horizontally or driven vertically to form a wall in the gully bed.

Answer 27

Pole / log check dam

Question 28

This type of check dam use of brushwood (sprouting or non-sprouting) that are packed firmly between two rows of post-drive across the gully bed.

Answer 28

Brushwood check dam

Question 29

- these are small channels/canals that run vertically on the slope. -used for removal of excess water from rainfall and under ground seepage. -controls gully erosion.

Answer 29

Drainage system/canals

Question 30

-Involves the use of ground works to control erosion. -Measures are generally employed in places where vegetation cannot be immediately established and in gullies and channels for riverbanks that have to be stabilized and protected.

Answer 30

Drainage System/canals

Question 31

-canals are designed to divert run-off from upper areas not to cause further damage to lower-lying areas. -Use to divert runoff from the gully head to prevent further enlargement and facilitate gully control works.

Answer 31

Diversion Ditches

Question 33

-Dug at varying intervals, depending on the slope's steepness, the steeper the slope, the closer the interval. -it follows the contour; they are 1 meter wide at the top, 0.5 m wide at the bottom and 0.5 m deep.

Answer 33

Diversion Ditches

Question 34

What are the types of structural/mechanical methods in soil erosion?

Answer 34

-Terracing -Contour canals -Contour Rock Walls -Gabions -Riprap -Stone walls -Farm ponds/water impounding dams -Check Dams/Drop Weirs Drainage System/canals -Diversion ditches

Question 35

What are the types of biological/agronomic approach?

Answer 35

1. Cover cropping 2. Multiple cropping 3. Strip cropping 4. Crop rotation 5. Relay cropping 6. Mulching 7. Contour hedgerows 8. Contour buffer strip planting 9. Alley cropping 10. Fascines 11. Wattling 12. Brush cover 13. French brush layers

Question 36

- involves the growth of cover crops such as grasses and / or legumes to protect the soil/ground surface from the impacts of raindrops which causes detachment and dispersion. - increase permeability and water infiltration rate through the biological loosening effect of the root system.

Answer 36

Cover cropping

Question 37

- A desirable cover crop should be fast-growing, hardy, and drought-resistant and can be used as feed for farm animals. This is similar to seeding in the planting of pastures grasses and legumes to serve as cover crops.

Answer 37

Cover cropping

Question 38

-this technique involves either sequential cropping, the growing of 2 or more crops a year in a sequence, intercropping the growing of 2 or more crops in the same piece of land at the same time.

Answer 38

Multiple cropping

Question 39

-refers to growing row crops (erosion permitting) and soil-conserving crops in alternate strips aligned on the contour. This is desirable in rolling areas ( with slope up to 25%) when terracing cannot be done due to the possible exposure of the subsoil or even the bedrock.

Answer 39

Strip cropping

Question 40

-refers to the systematic planting of different crops in succession on the same piece of land. This practice promotes the build-up to organic matter, improves soil structure, and promotes water's rapid infiltration in the long run.

Answer 40

Crop rotation

Question 41

-Practice of planting annual crops with the second crop planted after the first crop has flowered or nearing harvest. The objective is to allow the second crop to use residual moisture and continuously protect the soil from erosive rains and all through the year.

Answer 41

Relay cropping

Question 42

It is the practice that involves covering the soil with crop residues such as straw, corn stalks, palm fronds, or standing stubbles. This prevents surface scaling by preventing direct raindrop impact and enhancing biological activity decomposition, leading to the development of good soil structure. To be effective, a mulch should cover 70-75% of the soil surface.

Answer 42

Mulching

Question 43

A line usually planted to perennials close together to form a living wall, this wall blocks the rainwater pathways while the soil is caught behind the plants. This also used to slow down run off and deposit suspended soil particles.

Answer 43

Contour hedgerows

Question 44

- this is done by reducing the area devoted to the main crop by half on a very long slope. A narrow strip may be required near the base to avoid erosion resulting from the accumulation of unabsorbed water from the above slopes.

Answer 44

Contour buffer strip planting

Question 45

-involves establishment of woody hedgerows, usually leguminous trees, at regular intervals along the contours and the planting of agricultural in "alleys" formed between hedgerows. Soil erosion is minimized by trapping the sediments at the base of the hedgerows.

Answer 45

Alley cropping

Question 46

-bundles of long and dense brushwood of varying lengths. -for slope stabilization, the length should not exceed 3m -the bundles should form a straight cylinder, in building, a guide frame is prepared by two parallel rows of pegs 35 cm apart. Pieces of wire are placed across the ground before brushwood is bundled.

Answer 46

Fascines

Question 47

-Consists of interwoven brushwood fences in shallow trenches 25 cm deep where pegs are driven 50 to 70 cm apart between in which sprouting branches of species are woven.

Answer 47

Wattling

Question 48

Brushwood are laid covering the whole soil surface in the form of a mat.

Answer 48

Brush cover

Question 49

-thirty degree cut, slightly inclining towards the slope of about 1 m in width is constructed, and the branches are overlain in a netted manner. Soil from the upper slope is later used to cover the branches. These develop into an alley or hedge when cuttings have been established.

Answer 49

Brench brush layers

Question 50

What is SALT stands for?

Answer 50

Sloping Agricultural Land Technology

Question 51

-a strategy of using tree legumes to improve fertility and stability of agricultural soils. -provides a means for resource-poor farmers to achieve sustainable production without using chemical fertilizers.

Answer 51

SALT

Question 52

-A simple, applicable, low-cost method of upland farming.

Answer 52

SALT