Download 7-4 Soil

7-4 Soil
By Cyndee Crawford
September 2014
Soil Table of Contents
28. Chemical Weathering Lab
29. What is a Watershed? / Watershed Demo
30. Groundwater Layers Book
31. Groundwater Notes
32. What is an aquifer? / Surface Water
33. Surface Water
34. Surface Water Examples
35. SOIL profile
36. SOIL composition
37. SOIL texture/particle size
38. SOIL permeability
39. SOIL pH
40. Resources
Chemical Weathering Lab
p 29 7-4.5 Watersheds
Watersheds
● http://www.learn360.com/ShowVideo.a
spx?lid=26813561&SearchText=waters
hed&ID=1120447 (What is a
watershed?)
What is a Watershed? / Watershed Demo
1:17 / 9:34 min.
Describe what a
watershed is.
Describe how pollutants
enter the water.
p 29 7-4.5 Watersheds
Watersheds
● Watersheds are surface-water
drainage basins.
● Watersheds are important to
ecosystems and to human activities.
p 29 7-4.5 Watersheds
Watersheds
● Water is an important abiotic factor
within an ecosystem.
● Runoff - gravity causes some water
that falls to the Earth to flow downhill.
This is runoff.
p 30 7-4.5 Watersheds
Groundwater
● groundwater - water that soaks into
the ground
● Soil and rock that allow water to pass
through are called permeable.
● Create your
Groundwater Layers
Book
p 30 Groundwater Layers Book
● BP: Groundwater
o Take notes on
layers and
components
p 31 7-4.5 Watersheds
Groundwater
● The water enters the zone of aeration,
which is unsaturated.
● Groundwater will keep moving deeper into
Earth until it reaches a layer of rock that is
not permeable.
● (In other words, water will keep seeping into the
ground until it reaches a layer that will not let it pass
through. This layer has tightly packed particles.)
p 31 7-4.5 Watersheds
Groundwater
● The area where the water has filled all the
space in the soil is called the zone of
saturation.
● The top of the zone of saturation is the
water table.
p 31 7-4.5 Watersheds
Groundwater
● Groundwater can also flow slowly through
the underground rock
● or it can be stored in underground layers
called aquifers.
● Groundwater is naturally purified as it
soaks through the soil layers.
Will pollution reach your wells?
LAB
Making a groundwater model
LAB
p 32 What is an aquifer?
Answer the question:
What in an aquifer?
p 32 How Does an Aquifer Work?
Explain how an aquifer
works.
p 32 7-4.5 Watersheds
Surface-water
● Runoff that has not soaked into the
ground is surface-water.
● As runoff travels downhill, it forms the
water in streams and rivers.
p 32 7-4.5 Watersheds
Surface-water
● An area that is drained by a river and all
the streams that empty into it, the
tributaries, is called a drainage basin or
watershed.
● A divide is the high ground between two
drainage basins.
p 32 What is a meander?
Watch this mini video and explain what a
meander is.
p 33 7-4.5 Watersheds
Surface-water
● You can define the watershed area by
marking all the tributaries of that river.
p 33 7-4.5 Watersheds
● The availability of water as
groundwater or surface-water is
important to the ecosystems in that
area.
p 33 7-4.5 Watersheds
● Examples:
o
o
Flowing water can erode the land in one
location and deposit the sediments in another.
The floodplain of a river may deposit
sediment after heavy rains enriching the area
with new soil needed for growing vegetation.
 This new soil is nutrient rich.
 Crops or natural vegetation grow well in
this soil.
p 33 What is a Floodplain?
Explain what a
floodplain is.
p 33 7-4.5 Watersheds
● Examples:
o
o
The drainage basin provides the needed water
for animal life also.
Deltas may form where the river ends its
journey into a still body of water like a lake or
the ocean.
 A unique ecosystem forms in delta regions.
 Ex: the Santee delta in SC or the
Mississippi delta in Lousiana
p 33 How are deltas formed?
Explain how a delta is
formed.
Stream Table Model LAB
p 34 7-4.5 Watersheds
● Water is also important to human
activities.
● EX:
o
Human beings are dependent upon water for
survival, not only for drinking, but for agriculture
and industry as well.
p 34 7-4.5 Watersheds
● EX:
o
Dams have been placed along some rivers in
order
 to produce hydroelectric power
(hydro=water) and
 to offer recreation in the lakes that form
behind the dams.
p 34 7-4.5 Watersheds
● EX:
o
o
o
Lakes, rivers, and the ocean contain sources of
food and minerals.
Earth is 71% water with only 3% of that being
freshwater (that we drink).
Since much of the freshwater on Earth is in the
form of ice, very little is left as “usable”
freshwater for humans. (That is why we must
conserve water.)
p 35 7-4.4 Effects of Soil on Ecosystem
● Soil is one of the most valuable abiotic
factors in an ecosystem.
● Everything that lives on land depends
either directly or indirectly on soil.
Soil From Home LAB
p 35 BP: Soil
Take notes on:
● layers
● components (what
soil is made of)
● and more
p 35 7-4.4 Effects of Soil on Ecosystem
Soil Profile
● Soils form in layers, or horizons, and all the
layers make up the soil profile.
● a mature soil profile consists of 3 layers:
o topsoil
o subsoil
o parent material above bedrock
p 35 7-4.4 Effects of Soil on Ecosystem
Soil Profile
● Topsoil that is nutrient rich, containing a
mixture of humus, clay, and minerals, is most
suitable for plant growth.
● Most animals live in the topsoil horizon.
p 36 7-4.4 Effects of Soil on Ecosystem
Composition
● Soil is a mixture of rock particles, minerals,
decayed organic material, air, and water.
● The decayed organic matter in soil is humus.
● The sand, silt, and clay portion of soil comes
from weathered bedrock material.
p 36 7-4.4 Effects of Soil on Ecosystem
Composition
● The combination of these materials in soil:
o determines the soil type,
o affects the types of plants that grow well in
it,
o & affects the types of animals that can live
in it.
p 36 7-4.4 Effects of Soil on Ecosystem
Composition
● Factors that may affect soil type are:
o types of plants
o climate
o time
o slope of the land
p 37 7-4.4 Effects of Soil on Ecosystem
Texture
● Soil texture depends on the size of the
individual soil particles.
● Soil texture is determined by the relative
proportions of particle sizes that make up the
soil.
p 37 7-4.4 Effects of Soil on Ecosystem
Texture
● Texture names may include:
o loam
o sandy clay loam
o silt loam
o or clay
● The texture name depends on the percent of
sand, silt, and clay in the soil sample.
p 37 7-4.4 Effects of Soil on Ecosystem
Texture
● The texture affects the amount of water that
can be absorbed for use by plants and
animals.
p 37 7-4.4 Effects of Soil on Ecosystem
Particle Size
● Soil particles are classified by size ranging
from
o coarse sand (largest)
o to very fine sand (2nd largest)
o silt (2nd smallest)
o clay (smallest)
p 37 7-4.4 Effects of Soil on Ecosystem
Particle Size
● Soil particles that are larger than 2mm are
called gravel.
● Particle size also affects the amount of water
that can be absorbed and used by plants and
animals.
p 38 7-4.4 Effects of Soil on Ecosystem
Soil Quality is based on properties that can be
measured, such as permeability and pH.
p 38 7-4.4 Effects of Soil on Ecosystem
Permeability
● Soil particles have open spaces (pores)
between them that let water flow through.
● Permeability - how freely water flows through
soil
p 38 7-4.4 Effects of Soil on Ecosystem
Permeability
● The closer the particles pack together because
of particle size, the less permeable the soil is.
o Clay particles are small and closely packed, so they have
a LOW permeability. (Water does not flow through
easily.)
o Sand particles are large and loosely packed, so they
have a HIGH permeability. (Water does flow through
easily.)
p 38 7-4.4 Effects of Soil on Ecosystem
Permeability
● Measuring permeability involves calculating the
rate of drainage.
p 39 Soil pH (3:19 min)
Soil pH:
● Explain what soil pH is.
● Why is it important?
Hydrangeas:
● How can you change the color of
the Hydrangea flower?
p 39 7-4.4 Effects of Soil on Ecosystem
pH
● Soils can be classified as basic or acidic.
● Soils usually measure 4-10 on the pH scale.
● Indicators can be used to measure the pH of
soils.
p 39 7-4.4 Effects of Soil on Ecosystem
pH
● Most plants grow best in soils with of a pH of 5-7.
● If the pH in the soil is not suitable (at the right
level), organisms can’t access the nutrients in the
soil.
● Lime is a kind of fertilizer that alters pH.
● Lime can make soil more accessible for organisms
to get the nutrients they need.
Note: This is not the lime you eat.
p 40 7-4.6 Renewable or Nonrenewable
● All organisms on Earth, including humans, use resources
provided by the environment.
● Earth supplies a variety of natural resources that living things
use, change, and reuse.
● Some resources can be replaced and reused by nature;
these are renewable resources.
● Natural resources that cannot be replaced by nature are
nonrenewable.
p 40 7-4.6 Renewable or Nonrenewable
Renewable resources are replaced through natural processes
at a rate that is equal to or greater than the rate at which they are
being used.
● Air, freshwater, soil, living things, and sunlight are renewable
resources.
● Air can be cleaned and purified by plants during the process
of photosynthesis as they remove carbon dioxide from the air
and replace it with oxygen.
p 40 7-4.6 Renewable or Nonrenewable
Renewable resources ...
● The water cycle allows Earth’s water to be used over and
over within the environment.
● Topsoil is formed to replace soil that has been carried away
by wind and water (although new soil forms very slowly).
● Trees and other new plants grow to replace those that have
been cut down or died.
p 40 7-4.6 Renewable or Nonrenewable
Renewable resources ...
● Animals are born to replace animals that have died.
● Sunlight, or solar energy, is considered a renewable resource
because it will continue to be available for billions of years.
o It provides a source of energy for all processes on Earth.
p 40 7-4.6 Renewable or Nonrenewable
Nonrenewable resources are exhaustible because they are
being extracted and used at a much faster rate than the rate at
which they were formed.
● Fossil fuels (coal, oil, natural gas), diamonds, metals, and
other minerals are nonrenewable.
● They exist in a fixed amount and can only be replaced by
processes that take millions of years.
p 40 7-4.6 Renewable or Nonrenewable
Natural resources can be depleted or used to the point that they
are no longer available.
● Conservation measures are necessary for nonrenewable
resources because they are known to be in a on-replenishing
supply.
● If renewable resources are used at an increasing rate so that
they cannot be naturally replaced fast enough, they too can
be depleted.
p 40 7-4.6 Renewable or Nonrenewable
Natural resources ...
● Soil that is lost because it is left bare of vegetation and
allowed to erode depletes the land of the fertile topsoil
needed for plant growth in that area.
● Depletion of freshwater in an area caused by increased
demand by the population living there, by wasteful use of the
water, or by pollution, can result in water not being available
in needed quantities or being unfit for natural use.
p 40 7-4.6 Renewable or Nonrenewable
Natural resources ...
● Depletion of a living resource, such as trees being removed
without being replanted, can contribute to environmental
changes in the land, air, and water in that area.
p 40 7-4.6 Renewable or Nonrenewable
As the number of people on Earth gets larger, the need for
natural resources increases.
● The terms reduce, reuse, recycle and protect are important
ways that people can be involved in conservation of natural
resources.
p 40 7-4.6 Renewable or Nonrenewable
● Reducing involves making a decision to not use a resource
when there is an alternative, such as walking or riding a
bicycle rather than traveling in a car.
p 40 7-4.6 Renewable or Nonrenewable
● Reusing involves finding a way to use a resource (or product
from a resource) again without changing it or reprocessing it,
such as washing a drinking glass rather than throwing away
plastic or Styrofoam.
p 40 7-4.6 Renewable or Nonrenewable
● Recycling involves reprocessing a resource (or product from
a resource) so that the materials can be used again as
another item, such as metals, glass or plastics being remade
into new metal or glass products or into fibers.
p 40 7-4.6 Renewable or Nonrenewable
● Protecting involves preventing the loss of a resource,
usually living things, by managing their environment to
increase the chances of survival, such as providing wildlife
preserves for endangered animals.