….

- Introduction

- Prior knowledge

- Soil and Dirt

- What are soil Horizons?

- Types of soil

- Types of soil according to origen

- Bad uses of soil

- Good uses of soil

- Types of soil

- Types of soil according to origen

- How to conserve soil

- Question

- Where did soil come from?

- How is soil formed?

- Why do we need soil?

- What is a ped and their types

- Uses of soil

-Why do plants grow better in soil than in

sand?

-Can we lose soil?

-News

-Videos

-Quotes

-Posters

-Source

Soil is the very thin layer covering parts of

the crust of the earth that can be use to grow

our food. Today soil is endangered by

erosion. The chief factors responsible for

erosion are the overcultivation of marginal

soils, overgracing of vegetation by sheep and

goats, the cutting down of trees that anchor

the soil, and the overpumping of groundwater

that leaves the soil dry.

Soil VRS. Dirt

The substance that

plants, trees, etc.

Grow in; earth;

poor/dry/acid/sandy

soil.

1.A substance that

is not clean, such as

dust or mud.

2.A dirt track.

Is it "soil" or "dirt?"

Well, it depends. It's kind of like when a farmer

sees a stalk of corn, all on its own, out in the

middle of his soybeans - it "shouldn't otta' be

there!" If you find soil where it "shouldn't otta' be"

(like on your mom's nice, clean, kitchen floor, or all

over your clothes) then it can be considered "dirt"

because it makes things "dirty". On the other hand,

if you find soil where it's supposed to be (outside)

and doing what it's supposed to do (holding up

buildings, giving plants room to grow) then you

want to call it "soil" for sure!

Some people say that dirt is matter in the wrong

place.

A soil horizon is a layer parallel to the soil surface, whose

physical characteristics differ from the layers above and beneath.

Each soil type has at least one, usually three or four horizons.

Horizons are defined in most cases by obvious physical features,

chiefly color and texture. These may be described both in

absolute terms (particle size distribution for texture, for instance)

and in terms relative to the surrounding material, i.e. ‘coarser’ or

‘sandier’ than the horizons above and below.

Horizon formation (horizonation) is a function of a range of

geological, chemical, and biological processes and occurs over

long time periods. Soils vary in the degree to which horizons are

expressed.

They're the layers in the soil. The top layer is the O horizon. It's

only about an inch thick, but it is very healthy. The A horizon, or

topsoil, has roots, tiny microscopic bacteria and fungi, and lots of

other small creatures (like worms) running around in it. Next, is

the B horizon which is hard and not many plants and animals can

get through it. At the bottom is horizon C. C is the parent

material that was used to form the other three layers. It is even

harder than B and not many things live there.

In terms of soil texture, soil type usually refers to the

different sizes of mineral particles in a particular sample.

Soil is made up in part of finely ground rock particles,

grouped according to size as sand, silt and clay. Each size

plays a significantly different role.

For example, the largest particles, sand, determine

aeration and drainage characteristics, while the tiniest,

sub-microscopic clay particles, and are chemically active,

binding with water and plant nutrients. The ratio of these

sizes determines soil type: clay, loam, clay-loam, silt-loam,

and so on.

In addition to the mineral composition of soil, humus

(organic material) also plays a crucial role in soil

characteristics and fertility for plant life. Soil may be

mixed with larger aggregate, such as pebbles or gravel.

Not all types of soil are permeable, such as pure clay.

There are many recognized soil classifications, both

international and national.

Soil consists of rock fragments mixed with varying

amounts of organic material. The origen of soils depend

on the kind of rocks from which they were formed rocks

can be:

-Igneous, such as granite and basalt.

-Sedimentary, such as sand stone and limestone.

- Metamorphic, such as slate and marble.

HUMUS:

The organic constituent of soil, usually formed by the

decomposition of plants and leaves by soil bacteria is

called humus.

CONCLUTION: The origin the soil is determined by the

kind of rock from which it was form and the composition

of its organic content.

Overcultivation: When soil is over used it is

depleted of essential substances that plants need

to grow.

Overgrazing: Soils get depleted of vegetation

when animals feed on it at a pace that cannot be

sustained by replacement by new vegetation.

Forest Depletion: The cutting down of trees

that anchor the soil leaves the soil barren.

Rotation of crops: Changing kinds of crops

helps to preserve the nutrients of the soil.

Some crops tend to use different kinds of

components from the soil.

Leaving the soil fallow: Leaving the soil

without use gives it time to recover its

nutrients.

Preserving forests and creating new ones:

Vegetation prevents erosion and helps to

keep water sources.

Soil can be kept in good condition for farming

by keeping it from losing their nutrients. How to

conserve a particular soil depends on the

characteristics of the soil in question and the kind

of crop that is going or has been planted. Soils, for

example, generally lose nitrogen but it can be

replaced artificially.

It is important to prevent erosion. Soil must be

properly watered to keep it from drying. Soil must

be kept from strong winds that may turn it into

dust. Lack of water and strong winds make a

perfect combination for producing erosion.

WHAT IS SOIL?

Soil is the upper layer of earth in which plants grow. It is a mixture

of rock fragments, clay minerals and organic matter: The organic matter

consists largely of partially decomposed plant debris called humus.

HOW DO PEOPLE USE SOIL RESOURCE?

Soil is used mainly in the production of food.

SOIL:

Any type of rock may form the parent material of a soil. The

particles of rock typically vary in size down to microscopic fineness and

are intimately mixed with dark, partly decomposed plant debris called

humus. The humus content decreases with dept a great many factors are

involved in the production of soil including microorganisms such as

bacteria and fungi. Soil is important natural resources because it is the

source from in which plants absorb nutrients with their roots. Plants

serve as sources of animal food. Green plants produce their own

nutrients from the soil.

SOIL NITROGEN:

Nitrogen is an element essential for the construction of proteins.

Nitrogen is the main component of air but the nitrogen we get comes

from the soil. Plants absorb Nitrogen and some plants such as beans of

lentils produce proteins that contain nitrogen, animals also produce

proteins and we human beings get most of our proteins from animal

flesh.

Soil comes from solid rock which makes up the bulk of the

earth crust. Soil originates in the weathering of rock, a

complex disintegration process whose result is a coat of

rock fragments and clay minerals mixed up with varying

amounts of organic matter. Any type of rock may form the

parental material of soil. The particles of rock typically

vary in size down to microscopic fineness and are

intimately mixed with dark, partly decomposed plant

debris called humus. The humus content decreases with

dept a great many factors are involved in the production of

soil including microorganisms such as bacteria and fungi.

Soil is important natural resource because it is the source

from in which plants absorb nutrients with their roots.

Plants serve as sources of animal food. Green plants

produce their own nutrients from the soil.

Most of the soil here on earth has been around a long time. Soil is like a turtle when it comes to making new soil; it can take hundreds or thousands of years to make just one-inch more.

But soil has to start somewhere, right? It does. Soil forms

from its" parent material". This can be rocks, dead leaves,

broken tree limbs lying on the ground, and dead bugs.

Heat, rain, ice, snow, wind, and sunshine help to break the

parent material down into smaller and smaller pieces until

it becomes soil.

Soil originates in the weathering of rock, a complex disintegration

process whose result is a coat of rock fragments and clay minerals

mixed up with varying amounts of organic matter.

There are thousands of different soils throughout the world. Soils

are formed through a combination of five important factors.

Parent Material Earthy materials, both mineral and organic. Parent

material can be a volcanic deposit such as ash; it can be sediment

that has been transported and deposited by wind or water; or it can

be a deposit left by glaciers.

Climate - Parent material is broken down into finer particles by a

process called weathering, which is controlled by the climate of a

given location. Temperature and water are major climatic forces that

influence weathering.

Living Organisms - Both plants and animals help to create soils. As

they die, plants and animals add organic matter to weathered parent

material to help form subsoil and topsoil. As animals dig through the

soil, they break it up, permitting more are and water to enter.

Topography - Topography is the hilliness, flatness, or amount of

slope of the land.

Time - The age of a soil must be considered in thousands and even

millions of years since it may take hundreds of years for these

factors to form one inch of soil from parent material.

The main reason we need soil, simply put is that it sustains life on

this planet, along with Fire, Water and Air. We need it to grow food.

We also need soil to grow trees and plants to provide us with oxygen

to breath, and to stand up in it. Life attains certain elements and

compounds necessary to maintain, expand, and produce more life.

Aka vitamins and minerals soil maintains life by allowing plants and

microorganisms to flourish within it, thus supporting other life

forms...it provides a place to anchor things of our livelihood. All life

needs soil because it is a vital part of the ecosystem. Without soil,

plants could not grow and all animals that eat plants, including

humans, would not have anything to eat.

Soil covers the earth and gives us foundation for buildings. Soil is

very

important as it requires many years to form.

A ped is a single unit of soil structure (the shape of the soil). Soil

comes in several shapes:

granular -looks like cookie crumbs

blocky -blocks of different sizes

columnar -tall columns of soil that have a salt "cap" at the top

platy -thin, flat plates of soil stacked on top of each other

massive -very large clumps or clods of soil that are hard to break apart

The way a soil feels when you touch it is called its "texture." A soil that

feels "gritty" is made up of sand, the largest pieces of soil. A soil that

feels soft, silky or "floury" is made of the medium size soil pieces - silt.

The smallest size soil pieces, clay, feel "sticky" and are hard to squeeze.

We use soil to grow plants, nurture trees, freshen

veggies and fruits grow trees, crops, and build shelter.

Plant growth is a primary use of soil. It contains the

necessary nutrients and retains water. Its pH is a major

factor in how effective soil is for growing plants. The

desired range is between 6.0 and 6.5. Fertile soil allows

plants to receive the proper chemical reactions in order

to stimulate growth. Soil's ability to accommodate a

plant's root system is also important for the growth of a

plant.

Soil is a significant part of the construction industry. It is

used as a foundation for homes and buildings.

Construction professional’s use a process called soil

compaction to increase the density of the soil and ensure

its stability. Compacting the soil also prevents soil

settlement and reduces water seepage. Soil scientists

often measure the strength of soil before a construction

project to determine how easily the soil changes shape

and whether it is capable of maintaining under the weight

of a building. Working on the wrong type of soil may lead

to cracks in the foundation, leaks and floods.

Soil holds nutrients that plants need a lot better than

sand or clay. Clay is hard, so it makes it harder for roots

of plants to grow down to reach the water or nutrients

under it.

Soil has millions of pores which hold and store nutrients,

water, and oxygen so it can distribute it throughout out

the plant. Sand has too much ventilation which will not

be able to hold anything well.

The adequate soil depends on the plant being grown.

Some plants need more or less sand, more or less clay,

and more or less organic material. It all depends on the

plant being grown.

Can we lose soil?

Yes. Soil "erodes" (washes or blows away) when

there is nothing to help it stay in place.

How can we keep our soil in place?

Plant some grass, trees or other plants in areas

where the soil is eroding. They help keep soil from

moving around. Farmers have ways to keep the soil

on the land so that they can grow food for us to

eat. They use special machinery when they plant

their crops, and they plant windbreaks. Windbreaks

are rows of trees that are planted next to fields to

keep the wind from blowing the soil away.

When we try to save our soil it is called "soil

conservation." Conservation is the best way to be

sure that we have land to live on now and in the

future.

Soil and Strong Winds.

Today in China strong winds are sweeping millions of

tons of loose soil into the air in late winter and early

spring. The dust storms leave desert behind. Harvests in

China have been declining as a result of such ecological

catastrophes, and its worried government is trying

various schemes to keep the remaining soil in place.

The problem of soil erosion is not confined to China:

erosion by water as well as by wind contributes to the

loss of farmland soils in much of the world faster than

new soil is formed. Iowa has lost about half its topsoil in

the past 150 years.

http://www.youtube.com/watch?v=5h7rqIsOleU

http://www.youtube.com/watch?v=PK85skEXDQ8&feature=fvsr

http://www.youtube.com/watch?v=Ct6hNc4GLbQ&feature=fvwrel

http://www.youtube.com/watch?v=02MxCrzcFXY&feature=relmfu

All over the land are vast and handsome pastures, with

good grass for cattle, and it strikes me the soil would be

very fertile were the country inhabited and improved by

reasonable people.

Alvar N. C. de Vaca

As in the rankest soil the most beautiful flowers are

grown, so in the dark soil of poverty the choicest flowers

of humanity have developed and bloomed.

James Allen

At an unprecedented time with the worst attack ever on

our soil, our President displayed extraordinary

determination, leadership and resolve when history was

thrust upon him and the United States.

Olympia Snowed

At the age of nineteen and a half, I went to the Land of

Israel to till its soil and live by the labour of my hands. As

I did not find work, I sought my livelihood elsewhere.

Samuel Y. Agnon

SOURCE:

- “ The Physical Universe”

K. Krauskopf and A. Beiser.

Mc Graw Hill. 2008.

-Google

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Made by: Colleen Guzman Lorza