Transcript Chapter One - Glen Rose FFA

Chapter One
The Importance of Soil
The Importance of Soil

The history of Soil
– Dates back all the way to the Egyptians
civilization of 4,000 years ago
– Recently in the US history supplies
another example of soil misuse. This is
with the Dust bowl of the 1930’s.
– The Dust bowl was a drought that
misused the soil in having wind erosion.
The Importance of Soil
Additional acreage is lost due to
urbanization or degradation .
 Soil is a nonrenewable resource

The Importance of Soil
Most of the time we take soil for
granted.
 Soil is a very thin and often fragile
layer of life supporting material.

The Importance of Soil

Facts about the earth
– Earth consists of solid part (core, mantle,
and crust) and the atmosphere
surrounding it.
– Most of the earth is covered by sea
– Where continents exist the crust is thicker
– This is usually about 50 miles thick
The Importance of Soil
The atmosphere is about 170 miles
deep.
 The soil forms a very thin interface
between the two.

The Importance of Soil

What does living things need?
– Proper temperature
– Oxygen
– Water
– Carbon
– Other nutrients
– These factors are exchanged in the soil
that allow elements to be recycled rather
than lost
The Importance of Soil

Oxygen:
– Plant roots need oxygen to grow.
– Gases will pass in and out of the soil to
supply the oxygen for the roots
The Importance of Soil
– Temperature
 Plants
will grow best in certain soil
temperature ranges.
 Most plants will root in temperature around
40-50 degrees F.
 Water:
– Seldom stays in one place
The Importance of Soil

Carbon:
– Plant leaves collect sunlight to use the
energy in the process of photosynthesis.
– Which involves converting atmosphere
carbon to biological carbon
– Atmosphere carbon = carbon dioxide
– Biological carbon = simple sugars
The Importance of Soil

Nutrients :
– Plant nutrients are chemicals a plant
needs to grow.
– There are two types of nutrients cycles
 Nitrogen
cycle
 Mineral cycle
The Importance of Soil

Nitrogen:
– Comes directly from the atmosphere
where it occurs as a gas that plants
cannot use.
4 Needs of Soil

There are four needs of the soil
– Anchorage
– Water
– Oxygen
– Nutrients
4 Needs of Soil

Anchorage:
– This is where plants grow freely and are
firmly supported or anchored so they can
grow to reach the sunlight.
– Water:
– Soil will provide the plants with all the
water the plant needs
– Roots are the best water absorbing body .
4 Needs of Soil

Oxygen:
– Call creature even plants need oxygen.
Plants release oxygen during
photosynthesis but consume it during
respiration.
4 Needs of Soil

Nutrients:
– There are 16 nutrients usually considered
to be needed for plants.
– Plants obtain 13 of the 16 nutrients from
the soil itself.
– Other nutrients come from Air and water.
 Carbon
 Oxygen
 hydrogen
3 phase system

What is soil Matrix?
– It is the arrangement of solid particles
and pore spaces which consists of three
phases of solid , liquid, and gases.
3 phase system

The ideal Soil Type:
– 50% solid material
– 45 % mineral particles
– 5% organic matter
– 25% water
– 25% gases
3 phase system

Root Growth:
– Water reaches the root by two ways
either water flows toward the root
 Or the root grows into moist soil
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Ag Uses of Soil

Humans depend on soil to grow food,
fiber, timber, and ornamental plants.

Most Ag uses require different soil
types and management practices
4 Types of Ag Uses

1. Cropland:
– Cropland is land which soil is worked and
crops are planted, cared for, and
harvested.
– Crops that are grown
 Annual
crops are corn and soybeans
 Fiber crops are cotton horticultural crops like
vegetables.
4 Types of Ag Uses

Annual Crops:
– Require yearly soil preparation
– Perennial Forages:
– Are alfalfa.
– Which are crops that are in the ground for a few
years
– These crops keeps the soil completely cover and
keeps the soil in place.
4 Types of Ag Uses
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Perennial Hort. crops:
– This includes fruits, nuts, and nursery
stock
4 Types of Ag Uses
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2. Grazing Land:
– Much of the land in the US is grazed by
cattle and sheep
4 Types of Ag Uses
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3. Forest
– Foresters probably disturb soil the least,
– 4.
Other Uses
– This usually deals with growing plants in tiny pots
and usually with Landscapers
Non Ag Uses of Soil
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A few of the Non Ag uses of soil are:
– Recreation
– Foundations
– Waste Disposal
– Building Materials
Non Ag Uses of Soil
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Recreation:
– Recreational uses of the soil can be:
 Sitting
in a urban park and seeing kids play
on the playground, softball diamond,
 They can also be golf courses, campgrounds.
 Most demanding recreational use is the use
of playing fields. As most of the time there is
a demand to have good grow on turf that can
with stand about anything.
Non Ag Uses of Soil
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Foundations:
– A good builder usually will have the soil
tested to a dept of several feet.
– The structural soundness of a building
depends on the amount of soil that is
under the building.
Land Uses in the US
27% is in rangeland
 26% is in cropland
 27% is in forestland
 2% is in conservation reserve land
 4% is in other land
 6% is in urban land
 8% is in pastureland
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