This PPT is honor of International Year of Soil 2015

1. What is soil?
Soil is the thin layer of material on the Earth’s
surface. It is a natural resource consisting of
weathered and organic materials, air and water. As
it is the medium in which plants establish
themselves and grow, the most widely recognized
function of soil is its support for food production.
Soil provides nutrients and water that are absorbed
through plant roots and contribute to the regulation
of water and atmospheric gases and therefore play
an important role in climate regulation.

2. How are soils formed?
There are many different factors
that come together to create soils,
and the process can take thousands
of years to reach an equilibrium.
The main soil forming factors are:
climate, topography, parent
material, time and biological
factors (plants, animals, micro-
organisms and humans). Different
combinations and intensities of soil
forming factors lead to different
soil types.

3. Is it true that soil is a non-renewable resource?
Soil is considered a non-renewable resource
because it does not renew itself at a sufficient
rate in the human time frame. Indeed, one
centimetre of soil can take hundreds to
thousands of years to form from parent rock.

4. Why are soils important?
Soils are a key enabling resource for human well-being, central to the
creation of a host of products and essential ecosystem services:
Soils are the basis for the production of food, fibers, fuel and medicinal
products.
Soils absorb, store, alter, purify and release water, both for plant growth
and water supply.
Soils interact with the atmosphere through absorption and emission of
gases (e.g. carbon dioxide, methane, water vapour) and dust;
Soils make up the greatest pool of terrestrial organic carbon (over double
the organic carbon stored in vegetation).
Soils regulate carbon, oxygen and plant nutrient cycles (N, P, K, Ca, Mg,
etc.)

5. Soil is the habitat of several animals and
organisms such as bacteria and fungi and thus
sustain biological activity, diversity and
productivity.
Soil is the habitat for seed dispersion and
dissemination of the gene pool.
Soils buffer, filter and moderate the hydrological
cycle.
Soils are the platform for urban settlement and
are used as materials for construction.

6. How do soils contribute to food security?
Soil is where food begins! It is estimated that 95%
of our food is directly and indirectly produced on
our soils. Therefore, food availability relies on soils.
Healthy and good quality food can only be
produced if our soils are healthy. A healthy living
soil is a crucial ally to food security and nutrition.

7. How many types of soil exist in the world today?
Based on the different soil properties, there are
an infinite number of possible combinations that
can be grouped and classified in major soil
types/classes.

8. How many types of soil exist in the world today?
soil types are illustrated:
(1) Soils with organic layers;
(2) Soils showing strong human influence;
(3) Soils with limitations to root growth;
(4) Soils distinguished by their special iron and
aluminium chemistry;

9. How many types of soil exist in the world today?
(5) Soils with a dark and humus rich topsoil;
(6) Soils with accumulation of soluble salts;
(7) Soils with a subsoil enriched in clay;
(8) Soils with little or no development and
(9) Soils that are permanently flooded.

10. What is soil degradation?
Soil degradation is the reduction in the capacity of soil
to provide ecosystem goods and services and ensure
its functions over a period of time for the
beneficiaries of these. Soil degradation manifests
itself in various forms, such as: soil erosion, soil
Stalinization, nutrient depletion, loss of soil
biodiversity, soil pollution, soil compaction, loss
organic matter, soil sealing and others.

11. Is soil degradation a global issue?
Studies report that approximately 33% of our soils
are facing moderate to severe degradation. The
current rate of soil degradation threatens the
capacity to meet the needs of future generations,
unless we reverse this trend through a concerted
effort towards the sustainable management of soils.

12. What is soil health?
Soil health is the capacity of soil to function as a
living system. Healthy soils maintain a diverse
community of soil organisms that help to control
plant disease, insect and weed pests, and form
beneficial symbiotic associations with plant roots.

13. What is soil health? Continue:
Healthy soils recycle essential plant nutrients,
improve soil structure with positive repercussions
for soil water and nutrient holding capacity, and
ultimately improve crop production. A healthy soil
does not pollute the environment; rather, it
contributes to mitigate climate change by
maintaining or increasing its organic carbon
content.

14. What is Integrated Nutrient Management?
Integrated Nutrient Management refers to
the maintenance of soil fertility and plant
nutrient supply at an optimum level for
sustaining the desired productivity. This is
achieved by optimizing the benefits from all
possible sources of organic, inorganic,
biological and sustainable recyclable waste
components in an integrated manner, to
prevent environmental impacts from
nutrient outflows.

15. How do soils make plants grow?
Soils support plant growth by
providing anchorage, sufficient
oxygen, moisture and nutrients.
Additionally, soil protects roots from
drastic fluctuations in temperature
by buffering temperature
modification.

16. What is the role of fertilizers?
Fertilizers enrich soils content of
micro- and macronutrients. However,
overuse of fertilizers can result in soil
and water contamination.

17. How do soils contribute to climate change
mitigation and adaptation?
Sustainable management of soil resources
contributes effectively to the mitigation of: 1)
climate change through carbon sequestration and
reduction of GHG emissions; and

18. How do soils contribute to climate change
mitigation and adaptation?
2) desertification processes. It is imperative to
promote sustainable soil management practices
for climate change mitigation and adaptation, and
resilience to changing weather patterns and
extremes. Protection and management of organic
carbon-rich soils and the identification of zones
that are either highly vulnerable to degradation
or poorly resilient is of particular concern.

19. What is soil contamination?
Soil contamination implies that the
concentration of a substance (e.g.
nutrient, pesticide, organic chemical,
acidic or saline compound, or trace
elements) in soil is higher than would
naturally occur (See also soil
pollution).

20. What is soil pollution and how do soils
contribute to pollution control?
Soil pollution refers to the presence of substances
at concentrations above threshold levels where
they become harmful to living organisms (See
also soil contamination). Soils break down
pollutants and limit groundwater and surface
water pollution. Indeed, soils hamper pollutants
leaching into the groundwater and limit their
transport to surface waters.

21. How do soils store and filter water?
The ability of a soil to store water is called soil
water retention capacity and it is related to the
particle-size distribution. The particle-size
distribution is also related to the ability of a soil
to act as a filter. Indeed, the finer the soil
particles, the higher the ability of the soil to trap
pollutants and prevent them from leaching into
the groundwater.

22. How do soils recycle nutrients?
Nutrients in soil are recycled through the
decomposition of organic matter coming from
plant or animal sources. Soil microorganisms
break down the organic matter and make the
nutrients available to living organisms.

23. s it true that soils host a quarter of
our planet's biodiversity?
Yes, it is true. There are billions of
microorganisms such as bacteria,
fungi, and protozoans in the soil, as
well as thousands of insects, mites
and worms.

24. What is the role of soil biodiversity?
Soils and soil organisms provide a multitude of
ecosystem services, including waste breakdown,
release of nutrients, enhancement of soil
structure and biodegradation of pesticides and
other chemicals; in addition, they act as a sink for
greenhouse gas emissions and fight pests and

25. What is the role of soil biodiversity? Continued
soil-borne plant pathogens, benefiting human
and animal health including digestion and
immunity. It is therefore important to maintain
the genetic and species diversity of soil
organisms for the continued provision of these
functions.

26. What can I do to help protect the planet's soils?
To protect planet’s soil resources it is important to:
Prevent and reverse soil degradation
Practise sustainable soil management
Prevent soil pollution
Avoid sealing the soil
Combat climate change
Shrink your carbon footprint
Preserve and increase vegetation cover
Stop food waste
Spread the word about the importance of soils

27. Why is it important to raise awareness about the
importance of soils?
Soils provide a key set of fundamental ecosystem
services that are crucial for our well-being.
Despite their crucial role, soils have been taken
for granted for a long time. Considering that
human pressures on soils are reaching critical
limits that jeopardize our future, there is an
urgent need to raise awareness on the
importance of this strategic resource.

28. PRESENTED
BY
BENEDICTA PHILIP
12BSW4033
SOCIAL WORK DEPARTMENT
ST.JOSEPH’S COLLEGE (Art and Science)
BANGALORE
INDIA