7a - soil conservation and land management

What is soil conservarion

A combination of practices used to protect the soil from degradation

Where are most roots, nutrients, and organic matter found

Surface horizons (A)

What are some consequences of erosion

it can decrease soil fertility, which can affect crop yields

What do sediments do to surface waters

Sediment deposition in surface waters reduce their capacity to transport water, and they can overrun their banks (floods). They also reduce recreational and wildlife habitat

What is the difference between geological and accelerated erosion

Geological erosion is caused by nature, while accelerated erosion is caused by human activity

T/ F: Humans now more more soil material than all natrual processes combined

True

What are the three steps or processes of water and wind erosion

Detachment, transport, deposition

Aggregated soil particles

Natrually occuring, soil particles that cohere to eachother strongly. Formed through phsyical, chemical, and biological activity

Suspended soil particles

Small bits of soild material that can become transported and settle somewhere else

What are the three main types of water erosion

Sheet, rill, and gully

What are some fators affecting water erosion

• rainfall/ irrigation factors

• soil cover

• vegetation

• topography

• soil properties

rainfall/ irrigation factoes (water erosion)

intensity, duration

soil cover (water erosion)

protects from raindrops.irrigation, slows water movement

vegetation (water erosion)

slows water, roots hold soil in place

topography (water erosion)

degree of slope, length of slope, etc.

soil properties (water erosion)

mechanical, stability, BD, moisture, texture

soil crusts

caused by raindrop impact. reduces water infiltration. Increases runoff and erosion

Sheet erosion

relatively uniform erosion from the entire soil surface. Note that the perched stones and pebbles have protected the soil underneath form sheet erosion

Rill erosion

is initiated when the water concentrates in small channels (rills) as it runs off the soil. Subsequent cultivation may erase rills, but it does not replace the lost soil.

Gully Erosion

creates deep channels that cannot be erased by cultivation. Although gully erosion looks the most catastrophic of the three, for more total soil is lost by the less obvious sheet and rill erosion

T/F: Overstocking and poorly managed grazing is NOT a major cause of soil erosion and degradation worldwide

False

Mast Wasting

not gully erosion. the movement of rock and soil down slope under the influence of gravity

What are the three main types/ processes of wind erosion

• soil creep(sliding/ rolling)

• Saltation (bouncing)

• Suspension (long-term/ distance dispersal)

What factors affect wind erosion

• wind velocity

• surface roughness

• soil properties

• soil cover

• vegetation

wind velocity (wind erosion)

speed of wind

surface roughness (wind erosion)

tillage, effets, residues

soil properties (wind erosion)

mechanical stability, BD, moisture, texture

soil cover (wind erosion)

provides roughness, protects uderlying soil

vegetation (wind erosion)

slows wind, roots hold soil in place

What impact does the Sahara desert have

due to win erosion, soil particles are picked up and transported along the globe. This dust ends up fertilizing the Amazon.

soil creep (wind erosion)

sliding/ rolling

saltation

bouncing

suspension

long-term/ distance dispersal