chapter 8a

Question 1

soil erosion

Answer 1

detachment and transportation of soil particles by the forces of water/wind
process that transforms soil into sediment

Question 2

geologic erosion

Answer 2

natural process that wears down topographic highs and fills in topographic lows through deposition of eroded sediments

Question 3

accelerated erosion

Answer 3

exceeds normal geologic erosion
soil and natural vegetation are disturbed by human activity, 10 to 100 times more destructive

Question 4

characteristics of soil susceptible to erosion

Answer 4

1. low water infiltration capacity
2. low OM content
3. poor (unstable) structure
4. on steep hills
5. hydrophobic characteristics

Question 5

effects of soil erosion

Answer 5

1. loss of soil productivity
2. sediment pollution
3. loss of water
4. flooding
5. environmental degradation

Question 6

loss of soil productivity

Answer 6

topsoil erodes, B horizon exposed. lower foliage production, low water infiltration, and greater run-off

Question 7

sediment pollution

Answer 7

eroded sediment is rich in fertilizer/pesticide, it can upset the ecosystem at its deposition

Question 8

loss of water

Answer 8

decrease capability to hold water

Question 9

flooding and environmental degradation

Answer 9

flood in lower areas
destroys the environment

Question 10

off-site effects of soil erosion

Answer 10

a. siltation of dams, lakes, rivers
b. flood, soil, and water pollution

Question 11

type of erosion based on agent

Answer 11

1. water erosion
   - rainfall or splash erosion
   - runoff or scour erosion
2. wind erosion
3. erosion by ice

Question 12

mechanics of soil erosion

Answer 12

1. detachment or loosening of soil particles caused by flowing water or raindrops
2. transportation of soil particles by floating, rolling, dragging, and/or splashing
3. deposition of particles at some place in lower elevation

Question 13

causes of soil erosion in the PH

Answer 13

a. steep slopes (3/4 of land is hilly to mountainous)
b. highly erodible soils
c. high rainfall erosivity (intense and long rainfall)
d. poor vegetative cover in cultivated lands

Question 14

why should soil erosion be minimized

Answer 14

1. sustain or improve crop yields
2. reduce drainage costs maintenance
3. retain nutrients and chemical where applied
4. reduce hazards and catastrophe
5. help improve water quality

Question 15

type of erosion based on sequential occurrence

Answer 15

1. sheet erosion
2. rill erosion
3. gully erosion
4. stream channel erosion

Question 16

factors affecting degree of erosion

Answer 16

1. rainfall
2. soil erodibility (texture, structure, bulk density, porosity, infiltration, and water retention
3. topography
   4 vegetation
4. cropping practices
5. soil conservation practices

Question 17

how to minimize soil erosion

Answer 17

1. maintain good soil structure
2. protect soil surface by adequate crop and residue cover
3. use special erosion control practices

Question 18

principles in soil conservation

Answer 18

1. reduce runoff velocity
2. increase in water infiltration and water holding capacity
3. reduce of raindrop impact
4. increase in soil porosity and aggregation

Question 19

soil cosrvation practices

Answer 19

1. contour farming
2. cover cropping
3. alley cropping
4. terracing, rock wall, mechanical barriers
5. contour ditches, grassed waterways
6. farm ponds, check dams
7. reforestation
8. agroforestry
9. multiple cropping, mixed planting