Soil is a nonrenewable resource that provides many functions including being arable land for agriculture, regulating water and filtering pollutants, nutrient cycling, foundation and support, and containing mineral deposits. Human activities like soil erosion, compaction, intensive agriculture, urbanization, and desertification can degrade soil quality by reducing nutrients, organic matter, and biodiversity. Conservation methods include increasing soil organic matter, keeping the soil covered, reducing tillage, efficient pest and nutrient management, crop rotation, and preventing erosion and compaction.

1. SOIL AND SOIL QUALITY

2. Soil as a Resource
• It is a nonrenewable, finite resource that is not recoverable within the
human life span.

3. Soil Functions

4. Arable Land for Agriculture
• Soil is plowable land that could
be used to grow crops
• It can sustain plants and animal
life
• Agricultural land in the
Philippines comprises 41.7% of
the total land area.

5. Regulation of Water and Filtration of Potential
Pollutants
• In the water cycle, soil plays an important part in absorbing water and
storing it as groundwater.
• Water and dissolved solutes flow over the land and into and through
the soil
• The minerals and microbes in soil are also responsible for filtering,
degrading, immbolizing, and detoxifying organic and inorganic
materials.

6. Nutrient Cycling
• Carbon, nitrogen, phosphorus, and
other essential nutrients are stored,
transformed, and cycled into the
soil.
• Example: Nitrogen in the
atmosphere could not be readily
used by organisms. It must be first
converted to ammonium by
nitrogen-fixing bacteria and then
into nitrates by nitrifying bacteria
before it can be assimilated by
plants and transferred into the food
chain.

7. Foundation and Support
• Soil structures provide a base for
plant roots.
• Soils along the bedrock also
provide foundation and support
for human shelter and
structures, such as houses and
roads.

8. Mineral Deposits
• Soils are mined for their mineral content
(aluminum, iron, nickel, etc.)
• These soils are called laterites.
• They are formed in hot and wet tropical areas.
• They are mostly rusty-red in color because of
their high iron oxide content
• They develop through an extended chemical
weathering of the underlying parent rock,
resulting in the thick accumulation of metals in
soil.

9. How Human Activities Degrade
Soil Quality

10. Soil Degradation
• WHO: It is a change in soil health status resulting in a diminished
capacity of the ecosystem to provide goods and services to its
beneficiaries.

11. Human Activities that Degrade Soil
1. Soil erosion
• It is the absolute loss of topsoil
and nutrients.
• It is the most visible effect of soil
degradation
• It is a natural process but is
aggravated by poor
management practices.

12. Human Activities that Degrade Soil
2. Soil compaction
• It reduces the amount of air,
water, and space available to
roots and soil organisms.
• Example: repeated traffic or
traveling on wet soil

13. Human Activities that Degrade Soil
3. Desertification
• It is the irreversible change of
the land to a state where it can
no longer be recovered for its
original use.
• It is characterized by droughts
and arid conditions.
• It currently affects 1/6 of the
world’s population and 1/4 of
the world’s land

14. Human Activities that Degrade Soil
4. Intensive Agriculture
• It has been increasing since the 1960s in an
effort to feed the population more
efficiently.
• It has led to the use of more heavier
machinery, deforestation and clearing of
land
• It results in the loss of soil organic matter,
soil compaction, and damage to soil physical
properties.
• The overuse of pesticides and fertilizers also
led to pollution and the loss of soil flora and
fauna, which are essential parts of healthy

15. Human Activities that Degrade Soil
5. Urbanization
• Population growth has led to the
conversion of land to urban
centers (roads, pavements, and
concrete structures)
• These structures represent a
significant loss of soil
• It hinders the interaction of soil
with the atmosphere,
hydrosphere, and biosphere,
which affects nutrient cycling

16. Conservation of Soil Resources

17. Increasing Soil Organic Matter
• The addition of new organic
matter is important in improving
and maintaining soil quality.
• It also improves soil structure
and water- and nutrient-holding
capacities

18. Keeping the Soil Covered and Vegetated
• Ground cover and vegetation
protects the soil.
• It provides habitats for larger soil
organisms and improve water
availability
• Soil can be covered by leaving
crop residue on the surface or by
planting cover crops

19. Avoiding Excessive Tillage
• Tillage is done to loosen surface
soil and breakup soil structure
• Reducing tillage minimizes the
loss of organic matter and
protects the soil surface from
further erosion

20. Managing Pests and Nutrients Efficiently
• Efficient pest and nutrient
management requires regular
testing and monitoring
• Necessary chemicals should only
be applied at the right time and
place.

21. Promoting Crop Rotation
• Changing vegetation accross the
landscape over time allows the
soil to recover.
• It also increases the diversity of
plants and other organisms in
the area.

22. Reducing Erosion and Preventing Compaction
• Erosion can be prevented by
keeping the ground covered and
vegetated and by channelling
excess surface water runoff
• Soil compaction can be
prevented by restricting human
activities to designated areas
and pathways.