2. TODAY'S DISCUSSION
KEY TOPICS
What is Soil
How is Soil Formed
Layers of Soil
Importance of Soil
Properties of Soil
Types of Soil
Suitability of Soil to Plant
Growth and Development
3. the loose upper layer of
the Earth's surface where
plants grow
consists of a mix of
organic material
(decayed plants and
animals) and broken bits
of rocks and minerals
WHAT IS SOIL
4. Topsoil - uppermost
layer; where plants grow
Subsoil - where minerals
are found
Bedrock - hard layer;
parent rock
LAYERS OF SOIL
5. HOW IS
SOIL
FORMED
Time - It can take up to 1000 years
just for 1 inch of soil to form.
Living organisms - plants, fungi,
animals, and bacteria
Topography - the slope of the
surface of the land where soil is
formed
Climate
Parent material - minerals and
rocks that disintegrated to form soil
1.
2.
3.
4.
5.
Factors in
Soil
Formation
6. The Importance of Soil
Needed by plants to anchor themselves and as
source of nutrients
Serves as a habitat for living organisms
Source of raw materials
Has a role in recycling nutrients (nitrogen and
carbon)
Helps filter water (groundwater)
9. SAND
Size of particle - biggest; easily
seen and identified
Texture - coarse or rocky
Water-holding capacity - water
can pass through easily
10. SILT
Size of particle - has smaller
particles than sand
Texture - similar to clay
Water-holding capacity - can
hold some amount of water
11. CLAY
Size of particle - has the smallest
particles
Texture - smooth and sticky when
wet; hard and rough when dry
Water-holding capacity - dry clay
absorbs much amount of water until
sticky and wet; wet clay particles stick
together and leave no room for water
to pass through
12. Texture - gritty; contains pieces of plant
parts; porous
Color - dark color indicates presence of
humus (dark brown/black mass of
decaying matter)
Smell - large amount of humus gives an
earthy smell
Water-holding capacity - retains a high
amount of moisture due to its loose
particles and porous nature
LOAM Formed from a combination of sand, silt, and clay in
approximately equal amounts
15. Plants need soil in order to survive.
The soil contains the nutrients needed by plants.
16. Plants grow in different types of soil.
Tomatoes grow best in loam soil. Cactuses grow best in sandy soil.
17. Sand
the coarsest and the driest type of soil
allows air circulation, but cannot hold water
for long
suitable to plants that need less water
Cactus Aloe vera Oregano
18. Clay
the heaviest type of soil
good for holding water and nutrients
has limited air and water flow
Peanuts Rice
19. Silt combination of sand and clay
can hold nutrients and circulate air and
water better than clay
Cogon grass
20. Loam contains more nutrients, moisture, and
humus
best for growing vegetables
Gabi (Taro) Sunflower Corn
