Soil takes a long time to form, around 500-1000 years to form an inch of soil. Soil formation occurs in stages, starting with rocks being broken down by forces like wind and water into particles. In stage one, these particles form a mineral soil but cannot support life as they lack nitrogen. In stage two, lichens add nitrogen to the soil through nitrogen fixation. Mosses, bacteria and fungi also add nutrients and water. In stage three, larger plants that support roots can grow. Eventually, the soil supports thick vegetation in stage four. Reforestation, crop rotation, cover crops, and windbreaks can help conserve soil and prevent erosion.

3. How is Soil Formed and How Long Does It Take?
Soil formation is a long slow process. It's estimated that an
inch of soil takes 500 to 1000 years to form. Soil is
constantly being formed. It is also constantly being eroded.
Stage One
This is the rock pulverizing stage. Here the forces of wind,
rain, freezing and thawing water, earthquakes, volcanos all
work to slowly pulverize rocks into smaller partcles that can
make up a soil.
At the end of this stage we have most likely a combination of
sand, silt and clay sized particles. These form a mineral soil
like substance but are unable to support life.
They are missing nitrogen. It may seem nitrogen should be
the least of a being's worries. After all the air we breath is
made up of about 78% nitrogen gas. The problem is that
plants can not use nitrogen in this form. For them it needs to
be converted to either ammonia which is a combination of
nitrogen and hydrogen or nitrates - a combination of nitorgen
and oxygen.

4. Stage Two
This is the early stage of what we might call soil. Here we add some
life, specifically lichens.
Lichens are a symbiotic relationship of algae and fungus. The algae
has the very important role of fixing the nitrogen, changing it from
nitrogen gas to a form the plant can use. It also captures the sunlight
and creates sugars and oxygen. The fungus provides a place for the
algae to live, along with water and the mineral nutrients it needs.
Lichens are very long lived - hundreds to thousands of years and they also further
break down rock with acids they produce. About 8% of the earth is covered by
lichens.
Lichens are joined by mosses, bacteria, protozoa, and fungi. These form a complex
cooperatve community that works to store nitrogen, nutrients and water to foster
the growth of new plants.
Stage Three
At this time the little pockets of soil have formed to the extent that some larger
plants, plants with roots can have a go at growing.
The first pioneers will be short lived but as their bodies are added to the layers of
soil forming the soil becomes more capable of supporting life. Humus builds and
soil horizons begin to form.
Stage Four
The soils are developed enough to support thick vegetation

7. Dumping and decompusing

8. Biodegradable waste is a type of waste which can
be broken down, in a reasonable amount of time,
into its base compounds by micro-organisms and
other living things, regardless of what those
compounds may be.
Biodegradable waste can be commonly found
in municipal solid waste (sometimes called
biodegradable municipal waste, or BMW) as green
waste, food waste, paper waste, andbiodegradable
plastics. Other biodegradable wastes
include human waste, manure, sewage,
and slaughterhouse waste. In the absence
of oxygen, much of this waste will decay
tomethane by anaerobic digestion.

9. Climate change impacts
The main environmental threat from biodegradable waste is
the production of methane .
Uses of biodegradable waste
Biodegradable waste can be used for composting or a
resource for heat, electricity and fuel by means
of incineration or anaerobic digestion.Swiss Kompogas and
the DanishAIKAN process are examples of anaerobic
digestion of biodegradable waste. While incineration can
recover the most energy, anaerobic digestion plants retain
the nutrients and compost for the soil and still recover some
of the contained energy in the form of biogas. Kompogas
produced 27 million Kwh of electricity and biogas in 2009.
The oldest of the company's own lorries has achieved
1,000,000 kilometers driven with biogas from household
waste in the last 15 years.

10. Trash falls into one of two categories: either biodegradable or non-
biodegradable.While Biodegradable waste will eventually break
down and become part of the earth and soil, like food scraps and
paper. Non-biodegradable waste will NOTbreak down or at least
NOT break down for many years. Examples of Non-biodegradable
are plastics, metal and glass. Dangerous chemicals and toxins are
also non-biodegradable, as are plastic grocery bags, plastic water
bottles and other similar materials. Non-biodegradable trash has
been a growing concern to environmentalists, but now is becoming
a concern to anyone wanting to embrace a more eco-friendly
lifestyle; as world population grows so does our waste. It’s
becoming increasingly important to understand what non-
biodegradable waste is, as well as the effects that it has in on our
planet.

11. Non-biodegradable trash that is discarded to be land filled will
only accumulate. The most wide-reaching effect of non-
biodegradable trash is the Pacific Garbage Patch; an area of the
Pacific Ocean, which is heavily polluted with plastics and other
waste. “The patch extends over a very wide area, with estimates
ranging from an area the size of the state of Texas to one larger than
the continental United States; however, the exact size is unknown.”
It is estimated that unless consumers reduce current levels of non-
biodegradable waste, the Pacific Garbage Patch will double in size
in the next 10-20 years endangering the life of an infinite amount of
marine animals.
All hope is not lost, and there are ways to prevent the accumulation
of non-biodegradable waste. The most common one available to
everyone is to recycle. Another solution is to replace non-
biodegradable materials with ones specifically designed to
biodegrade; and also supporting companies that are striving to
help our environment. Above all “Say No To Plastic Bottles! – Say
No To Plastic Bags!”

12. Major soil pollutants and their effect on human health
Metal Source Effects
Arsenic occurs naturally Chronic poisoning leads to a loss of
appetite and weight, diarrhea, alternating
with constipation, gastro intestinal
disturbances, peripheral neuritis,
conjunctivitis and sometimes skin cancer
Cadmium mining, metallurgy chemical industry and
electroplating
leads to chronic poisoning and affects the
proximal tubules of the kidney, causing
formation of kidney stones
Lead lead smelters storage battery lead poisoning can lead to severe mental
retardation or death
Mercury industrial wastes methyl mercury compounds are much more
toxic than other forms of mercury, causes
neurological problems and damages renal
glomeruli and tubules
Cyanides wastes from heat treatment of metals,
dismantling of electroplating shops, etc.
rapid death may follow due to exposure to
cyanide as a result of inhibition of cellular
respiration

13. Effects of soil pollution

14. 1.Industrial Activity: Industrial activity has been the biggest
contributor to the problem in the last century, especially since
the amount of mining and manufacturing has increased. Most
industries are dependent on extracting minerals from the Earth.
Whether it is iron ore or coal, the by products are contaminated
and they are not disposed off in a manner that can be
considered safe. As a result, the industrial waste lingers in the
soil surface for a long time and makes it unsuitable for use.
2. Agricultural Activities: Chemical utilization has gone up
tremendously since technology provided us with modern
pesticides and fertilizers. They are full of chemicals that are not
produced in nature and cannot be broken down by it. As a
result, they seep into the ground after they mix with water and
slowly reduce the fertility of the soil. Other chemicals damage
the composition of the soil and make it easier to erode by water
and air. Plants absorb many of these pesticides and when they
decompose, they cause soil pollution since they become a part
of the land.

15. 3. Waste Disposal: Finally, a growing cause for concern is how we
dispose of our waste. While industrial waste is sure to cause
contamination, there is another way in which we are adding to the
pollution. Every human produces a certain amount of personal waste
products by way or urine and feces.
While much of it moves into the sewer the system, there is also a large
amount that is dumped directly into landfills in the form of diapers. Even
the sewer system ends at the landfill, where the biological
waste pollutes the soil and water. This is because our bodies are full of
toxins and chemicals which are now seeping into the land and causing
pollution of soil.
4. Accidental Oil Spills: Oil leaks can happen during storage and
transport of chemicals. This can be seen at most of the fuel stations.
The chemicals present in the fuel deteriorates the quality of soil and
make them unsuitable for cultivation. These chemicals can enter into
the groundwater through soil and make the water undrinkable.
5. Acid Rain: Acid rain is caused when pollutants present in the air
mixes up with the rain and fall back on the ground. The polluted
water could dissolve away some of the important nutrients found in soil
and change the structure of the soil.

18. Control of Soil Pollution
1. 1.Use of pesticides should be minimized.
2. Use of fertilisers should be judicious.
3. Cropping techniques should be improved to
prevent growth of weeds.
4. Special pits should be selected for dumping
wastes.
2.5. Controlled grazing and forest management.
6. Wind breaks and wind shield in areas exposed
to wind erosin .
7. Planning of soil binding grasses along banks
and slopes prone to rapid erosin.
8. Afforestation and reforestation.

21. Reducing Usage of Chemicals
1.Pesticides and fungicides are essential for plant growth but
their overuse has led to soil pollution. Bio-fertilization and
manures should be used instead of their chemical alternatives.
Biofertilization is a process in which certain microorganisms
are used to increase the fertility and growth capacity of soil.
The process reduces the need for pesticides and fungicides.
Manure, meanwhile, is always considered preferable to
pesticides. In its organic form, manure has few negative effects
on the ecological system.
2.Recycling is another way to reduce and control soil pollution.
Recycling paper, plastics and other materials reduces the
volume of refuse in landfills, another common cause of soil
pollution.

22. 3.De-forestation, the cutting down of trees, causes erosion,
pollution and the loss of fertility in the topsoil. Planting trees--
or re-forestation--helps prevent soil erosion and pollution.
4.Weeds soak up minerals in the soil. Reducing weed growth
helps reduce soil pollution. One of the more common methods
of reducing weed growth is covering the soil with numerous
layers of wet newspapers or a plastic sheet for several weeks
before cultivation. This prevents light from reaching the weeds,
which kills them.
5.Designated pits should be used for the dumping of soil
wastes. These wastes should be treated chemically and
biologically to make them less toxic and hazardous. Biological
treatment involves the use of anaerobic microorganisms, such
as methanogens and acetogens, which help break down the soil
wastes into a less toxic and biodegradable form.

23. Reuse is to use an item again after it has been used. This
includes conventional reuse where the item is used again
for the same function, and new-life reuse where it is used
for a different function. In contrast, recycling is the
breaking down of the used item into raw materials which
are used to make new items. By taking useful products and
exchanging them, without reprocessing, reuse help save
time, money, energy, and resources. In broader economic
terms, reuse offers quality products to people and
organizations with limited means, while generating jobs
and business activity that contribute to the economy.

24. Recyclable materials include many
kindsof glass, paper, metal, plastic, textiles
, and electronics. The composting or other
reuse ofbiodegradable waste—such
as food or garden waste—is also
considered recycling. Materials to be
recycled are either brought to a collection
center or picked up from the curbside,
then sorted, cleaned, and reprocessed into
new materials bound for manufacturing.

25. In the strictest sense, recycling of a material would produce a fresh supply of
the same material—for example, used office paper would be converted into
new office paper, or used foamed polystyrene into new polystyrene. However,
this is often difficult or too expensive (compared with producing the same
product from raw materials or other sources), so "recycling" of many products
or materials involves their reuse in producing different materials
(e.g., paperboard) instead. Another form of recycling is the salvage of certain
materials from complex products, either due to their intrinsic value
(e.g.,lead from car batteries, or gold from computer components), or due to
their hazardous nature (e.g., removal and reuse of mercury from various
items). Critics dispute the net economic and environmental benefits of
recycling over its costs, and suggest that proponents of recycling often make
matters worse and suffer from confirmation bias. Specifically, critics argue
that the costs and energy used in collection and transportation detract from
(and outweigh) the costs and energy saved in the production process; also that
the jobs produced by the recycling industry can be a poor trade for the jobs
lost in logging, mining, and other industries associated with virgin
production; and that materials such as paper pulp can only be recycled a few
times before material degradation prevents further recycling. Proponents of
recycling dispute each of these claims, and the validity of arguments from
both sides has led to enduring controversy.

27. Reforestation
Mountain valley and forest plantings have unique requirements.
Species selection is dependent on elevation and slope aspect.
Planting within an existing forest (or where a forest once existed)
is called reforestation. Reforestation can:
•Increase wildlife habitat
•Provide for future forest production
•Diversify forest species composition
•Replace trees lost to insects, diseases or fire
Many reforestation projects involve minimal site preparation and
tree maintenance, and may involve planting large numbers of
trees per acre due to expected mortality.
Generally, irrigation is not used to supplement natural moisture,
but use of mulch is effective.
These publications offer more information on planning, designing
and preparing sites for planting; designing windbreaks; and
planting to promote wildlife.

28. How does reforestation prevent
soil erosion?
Reforestation is to plant trees in
forests that have been deforested.
The roots of the trees hold the soil
together therefore not having soil
erosion. But soil erosion can still be
done through humans, animals and
other elements.

29. Soil conservation is a set of management
strategies for prevention of soil being eroded from
the Earth’s surface or becoming chemically altered by
overuse, acidification,salinization or other chemical soil
contamination. It is a component of environmental soil
science.
Decisions regarding appropriate crop rotation, cover crops,
and planted windbreaks are central to the ability of surface
soils to retain their integrity, both with respect to erosive
forces and chemical change from nutrient depletion. Crop
rotation is simply the conventional alternation of crops on
a given field, so that nutrient depletion is avoided from
repetitive chemical uptake/deposition of single crop
growth.

30. Tree plantings benefit land and people by:
Protecting property and livestock from wind
Restoring or enhancing natural beauty
Reducing soil erosion and improving crop yields
Providing food and cover for wildlife
Increasing property values
Improving forest health
Reducing water evaporation, preserving winter moisture, and
protecting and improving water quality
Controlling drifting snow
Reducing atmospheric carbon dioxide
Reducing heating and cooling costs (by providing protection from
the sun and wind, trees can reduce energy costs by as much as 30
percent)
Protecting livestock from the elements, maintaining and
improving livestock weight, and reducing calving losses
Increasing our supply of renewable resources

31. Some factors to consider in planning a tree planting,
whether in the mountains or on the plains or whether it is
designed to control wind or snow, or benefit wildlife:
•Location
•Elevation, slope and aspect
•Soil type and alkalinity
•Prevailing wind direction(s)
•Weed control methods
•Supplemental irrigation
•Snow drifting
•Power lines
•Planting size and shape
•Species selection
•Site preparation methods
•Underground utility locations
•Past land uses

32. In agriculture, a Terrace is a piece of sloped
plane that has been cut into a series of
successively receding flat surfaces or platforms,
which resemble steps, for the purposes of more
effective farming. This type of landscaping,
therefore, is called terracing. Graduated terrace
steps are commonly used to farm on hilly or
mountainous terrain. Terraced fields both
decrease erosion and surface runoff, and may be
used to support growing crops that require
irrigation, such as rice. The rice terraces of the
Philippine Cordilleras have been designated as
UNESCOWorld Heritage Site because of the
significance of this technique.

33. Terraced
farmland in
Peru,
adopted by
the Inca.

34. Terraced hay
fields in
the Upper
Mississippi
River basin
during the
1930s.

35. Jatiluwih
rice terrace
in Bali,
Indonesia.

36. The Banaue
Rice
Terraces in
Ifugao,
Philippines.

37. Rice
cultivation,
Lower
Himalayas,
Nepal.

38. Terraced fields
in Sa Pa,
Vietnam.

39. No-till farming
(also called zero tillage or direct drilling) is
a way of growing crops or pasture from year to year
without disturbing the soilthrough tillage. No-till is an
agricultural technique which increases the amount of
water that infiltrates into the soil and increases organic
matter retention and cycling of nutrients in the soil. In
many agricultural regions it can reduce or eliminate soil
erosion. It increases the amount and variety of life in and
on the soil, including disease-causing organisms and
disease suppression organisms. The most powerful
benefit of no-tillage is improvement in soil biological
fertility, making soils more resilient. Farm operations are
made much more efficient, particularly improved time of
sowing and better trafficability of farm operations.

40. Tilling is used to remove weeds, shape the soil into
rows for crop plants and furrows for irrigation. This leads
to unfavorable effects, likesoil compaction; loss
of organic matter; degradation of soil aggregates; death
or disruption of soil microbes and other organisms
including mycorrhiza, arthropods,and earthworms;[1] and
soil erosion where topsoil is washed or blown away. No-
till farming avoids these effects by excluding the use
of tillage. With this way of farming, crop residues or
other organic amenities are retained on the soil surface
and sowing/fertilizing is done with minimal soil
disturbance. Continuous no-till needs to be managed
very differently in order to keep or increase yield on the
field. Residue, weeds, equipment, crop rotations, water,
disease, pests, and fertilizer management are just some

43. Contour ploughing or contour farming
the farming practice of ploughing and/or planting across a slope
following its elevation contour lines. These contour lines create a
water break which reduces the formation of rills and gullies during
times of heavy water run-off; which is a major cause of soil
erosion. The water break also allows more time for the water to
settle into the soil. In contour plowing, the ruts made by the plow
run perpendicular rather than parallel to slopes, generally resulting
in furrows that curve around the land and are level. This method is
also known for preventing tillage erosion.[Tillage erosion is the soil
movement and erosion caused by tilling a given plot of land.[3] A
similar practice is contour bunding where stones are placed
around the contours of slopes.
Soil erosion prevention practices such as this can drastically
decrease negative affects associated with soil erosion such as
reduced crop productivity, worsened water quality, lower effective
reservoir water levels, flooding, and habitat destruction.[4] Contour
farming is considered an active form of sustainable agriculture.

45. Crop rotation is the practice of growing a
series of dissimilar/different types of crops in the
same area in sequential seasons.
Crop rotation gives various nutrients to the soil. A
traditional element of crop rotation is the
replenishment of nitrogen through the use ofgreen
manure in sequence with cereals and other crops.
Crop rotation also mitigates the build-up
of pathogens and pests that often occurs when one
species is continuously cropped, and can also
improve soil structure and fertility by alternating
deep-rooted and shallow-rooted plants. Crop
rotation is one component of polyculture.

47. The soil pH is a measure of the acidity or
alkalinity in soils. pH is defined as the
negative logarithm (base 10) of
the activity of hydronium ions (H+
or, more precisely, H
3O+
aq) in asolution. In water, it nomally ranges from -1 to 14,
with 7 being neutral. A pH below 7 is acidic and above 7 is
alkaline. Soil pH is considered a master variable in soils as
it controls many chemical processes that take place. It
specifically affects plant nutrient availability by controlling
the chemical forms of the nutrient. The optimum pH
range for most plants is between 5.5 and 7.0,[1] however
many plants have adapted to thrive at pH values outside
this range.

48. Global variation in soil pH. Red = acidic soil. Yellow = neutral
soil. Blue = alkaline soil.Black = no data

50. Denomination pH range
Ultra acid < 3.5
Extreme acid 3.5–4.4
Very strong acid 4.5–5.0
Strong acid 5.1–5.5
Moderate acid 5.6–6.0
Slight acid 6.1–6.5
Neutral 6.6–7.3
Slightly alkaline 7.4–7.8
Moderately alkaline 7.9–8.4
Strongly alkaline 8.5–9.0
Very strongly alkaline > 9.0
Classification of soil pH ranges
The United States Department of Agriculture Natural Resources Conservation Service,
formerly Soil Conservation Service classifies soil pH ranges as follows:

51. Soils can process and contain considerable
amounts of water. They can take in water, and
will keep doing so until they are full, or until
the rate at which they can transmit water into
and through the pores is exceeded. Some of
this water will steadily drain through the soil
(via gravity) and end up in
the waterways and streams, but much of it
will be retained, away from the influence of
gravity, for use of plants and
other organisms to contribute to land
productivity and soil health.

52. Soil water retention
Pores (the spaces that exist between soil particles) provide for the
passage and/or retention of gasses and moisture within the soil
profile. The soil's ability to retain water is strongly related to particle
size; water molecules hold more tightly to the fine particles of
a clay soil than to coarser particles of a sandy soil, so clays generally
retain more water.[1]Conversely, sands provide easier passage or
transmission of water through the profile. Clay type, organic content,
and soil structure also influence soil water retention.[2]
The maximum amount of water that a given soil can retain is
called field capacity, whereas a soil so dry that plants cannot liberate
the remaining moisture from the soil particles is said to be at wilting
point.[1] Available water is that which the plants can utilize from the
soil within the range of field capacity and wilting point.
The role of soil water retention is profound; its effects are far reaching
and relationships are invariably complex. This section focuses on a
few key roles and recognizes that it is beyond the scope of this
discussion to encompass all roles that can be found in the literature.

53. Accumulation of excess salts in the root zone resulting in a partial or
complete loss of soil productivity is a worldwide phenomenon. The
problems of soil salinity are most widespread in the arid and semi-
arid regions but salt affected soils also occur extensively in sub-
humid and humid climates, particularly in the coastal regions where
the ingress of sea water through estuaries and rivers and through
groundwater causes large-scale salinization. Soil salinity is also a
serious problem in areas where groundwater of high salt content is
used for irrigation. The most serious salinity problems are being
faced in the irrigated arid and semi-arid regions of the world and it
is in these very regions that irrigation is essential to increase
agricultural production to satisfy food requirements. However,
irrigation is often costly, technically complex and requires skilled
management. Failure to apply efficient principles of water
management may result in wastage of water through seepage; over-
watering and inadequate drainage result in water logging and
salinity problems which reduce the soil productivity, eventually
leading to loss of cultivable land.

54. soil organism, any organism inhabiting the soil during part or
all of its life. Soil organisms, which range in size from
microscopic cells that digest decaying organic material to small
mammals that live primarily on other soil organisms, play an
important role in maintaining fertility, structure, drainage, and
aeration of soil. They also break down plant and animal tissues,
releasing stored nutrients and converting them into forms
usable by plants. Some soil organisms are pests. Among the soil
organisms that are pests of crops are nematodes, slugs and
snails, symphylids, beetle larvae, fly larvae, caterpillars, and root
aphids. Some soil organisms cause rots, some release substances
that inhibit plant growth, and others are hosts for organisms that
cause animal diseases.
soil organism, any organism inhabiting
the soil during part or all of its life. Soil organisms,
which range in size from microscopic cells that
digest decaying organic material to small mammals that
live primarily on other soil organisms, play an important
role in maintaining fertility, structure, drainage, and
aeration of soil. They also break down plant
and animal tissues, releasing stored nutrients and
converting them into forms usable by plants. Some soil
organisms are pests. Among the soil organisms that are
pests of crops are nematodes, slugs and snails,
symphylids, beetle larvae, fly larvae, caterpillars, and
root aphids. Some soil organisms cause rots, some
release substances that inhibit plant growth, and others
are hosts for organisms that cause animal diseases.

56. Indigenous crops
Planting of native crops is
known to be beneficial for
soil conservation.if non-
native plants are grown , the
fields should be bordered by
indigenous crops to prevent
soil erosion and achieve soil
conservation.a