Honors Env. Earth Science - Ecology : soils

What are the soil seperates?

Sand, silt, and clay

size/properties of sand particles in soil seperation

2 - 0.05 mm in diameter

size/properties of silt particles in soil seperation

0.05-0.002 mm in diameter

size/properties of clay particles in soil seperates

less than 0.002 mm in diameter

What is soil composed of percantage wise?

45% rock material

5% organic matter

50% empty spac

In soil, what percantage is rock material?

45%

In soil, what percantage is organic matter?

5%

In soil, what percantage is empty space?

50%

In soil, what is the rock material made up of?

sand, silt, and clay

In soil, what is a type of organic matter present?

Humus

In soil, what is the empty space made up of?

air and water

What is humus, in terms of organic matter in soil?

black/dark brown organic material that remains after decomposition

What is humus, in terms of soil, decomposed of?

Leaf litter, animal dung, and decaying organisms

What does humus do for soil?

It increases soil’s water-holding capacity by acting like a sponge

How is soil formed? (general explanation)

from parent material that is slowly broken down through weathering processes

What are the 5 soil-forming factors?

Climate, biology, relief, parent material, and time

What is mechanical weathering?

when over time, forces from the natural environment cause rocks to physically break down

What is Frost Wedging?

A form of physical weathering that involves the breaking of rock, the repeated freezing and thawing of water found in rock cracks, joints, pushes the rock to the breaking point

Where does frost weding typically occur?

In areas with extremely cold conditions with sufficient rainfall

Describe the biological process of physical weathering of Root Wedging

Roots force their way into tiny cracks in rocks and as they grow, they force open and crack open the rock

Describe the biological form of weathering, Worm Holes

Worm holes allow water to enter into the soil, and if water enters into cracks, freezing and thawing cycles can break it open. Water also leeches elements from rocks weakening them so they break apart easier

What is chemical weathering?

The erosion or disintegration of rocks caused by chemical reactions

What is Hydrolysis?

When water reacts with minerals and replaces ions, forming new minerals (usually clays).

H+ ions in acidic water replace metallic _______ like Mg²+ , Ca²+ , Na²+ , K^+1 , which are essential for _____ _______.

cations, plant growth

When Feldspar turns to Kaolinite clay, it releases dissolved ____ (like K^+) into soil

ions

how do nutrients become available to plants in soil?

when dissolved ions are released into soil

Why does soil get red, yellow, or orange colors?

because of iron oxidizing

How was the soil in New England formed?

Through glaciers moving the ground

What are soil horizons?

The chemically and texturally different layers of soils

How do soil horizons form?

through the downward movement of clay, water, and dissolved ions

What are the 5 basic soil horizons?

Surface layer, topsoil, subsoil, parent material, bedrock

What is the name of the O horizon and what is it made of?

Surface layer made of organic debris and partly decomposed materials

What is the name of the A horizon and what is it made up of?

Topsoil made of mineral particles mixed with organic material

What is the B horizon and what is it made up of?

Subsoil made of compounds draining from above accumalate

What is the E horizon?

Leaching layer

What is the C horizon and what is it made up of?

Parent material made of partly weathered rocked

What is the R horizon?

Bedrock

Soil minerals are often present as ____.

ions

true or false : Mineral ions are either positively or negatively charged

true

clay particles have mostly ________ charges on their outer surfaces

negative

Do sands and silts have charges? (positive or negative)

no

Positively charged mineral ions are _______ to the soil particles and are ____ on for plant use. These include potassium (K^+) and magnesium (Mg²+)

attracted, held

Negatively charged mineral ions are ________ by the soil particles and are ______ away from roots. This includes nitrate (NO3)

repelled, washed

Cation Exchange Capacity (CEC) is the _____ amount of cations that a soil can retain

total

The higher the soil CEC (Cation Exchange Capacity) the ______ ability it has to store plant nutrients

greater

How can soil CEC (Cation Exchange Capacity) increase?

When the amount of clay, the amount of organic matter, or the soil pH increases

Root hairs release H+ ions which knock off _______ from clay soil particles. These include root hairs take up these released ______ (nutrient) into the plant (same word for both empty spaces)

cations

What is the purpose of organic matter (soil)?

stores nurtrients used by plants, produces small colloids with a large surface area

What are ways to protect soil from erosion?

Windbreaks, no-till farming, not logging on slopes, farming through terracing, contour plowing, and crop rotation

What are two reasons for how dustbowls are created?

severe, extended drought and destructive agricultural practices. Erosion of soil

How to calculate height of tree

your height to eye level + distance from tree = height of tree

How to calculate diameter of tree

Measured length around tree / pi (3.14)

How to find number of 16 foot logs to top of tree

calculated height of tree / 16

How to find number of cords of wood found in tree

Board feet of lumber (from table) / 500 board feet (1 cord = 500 board feet)

How much board feet is 1 cord of wood equal too?

500 board feet

Ways to sustainably manage Earth’s resources?

Reduce, reuse, recycle ; educating oneself ; conserving water ; use more renewable sources of energy than nonrenewable

Solutions to human impacts when obtaining resources?

Priortizing sustainable practices, shifting to renewable energy, and recycling materials

How to calculate % error?

( (measured value - actual value) / actual value ) x 100%

What are the 5 steps in the nitrogen cycle?

Nitrogen fixation, nitrification, assimilation, ammoniafication, de-nitrification

What are ways nitrogen can get fixed?

lightning causing nitrogen gas to react with oxygen making nitrate; rhizobium bacteria in soil coverting nitrogen to gas; legumes, trees, and beans can fix nitrogen - rhizobium bacteria found in these plants

what is nitrification?

the bacterial conversion of ammonium into nitrate

what is nitrate?

plant friendly form of nitrogen

what is assimilation (in nitrogen cycle)?

the process by which plants take in and use nitrate ions to make amino acids and proteins

Assimilation is the step in the nitrogen cycle where animals get _________ into their tissue

nitrogen

what is ammoniafication?

breaking down of nitrogen in dead bodies (plants and animals) into ammonia

what is de-nitrification?

the return of nitrogen back into the atmosphere down by anaerobic bacteria

what is step 1 in nitrogen cycle?

nitrogen fixation

what is step 2 in nitrogen cycle?

nitrification

what is step 3 in nitrogen cycle?

assimilation

what is step 4 in nitrogen cycle?

ammoniafication

what is step 5 in nitrogen cycle?

de-nitrification