This document provides information about soil composition and properties. It discusses the five factors that influence soil formation: climate, organisms, relief of the land, parent material, and time. It also describes different soil types including pedalfer, pedocal, and laterite soils. The document outlines various soil properties such as texture, color, horizons, nutrients, and pH. It discusses how these properties are tested and provides examples of soil texture, nutrient, and pH tests. Agricultural practices to conserve topsoil and add fertilizer are also outlined.

1. Soil & Water 2:
“Soil”
ppt. by Robin D. Seamon

2. Weathering- breaking down of rock pieces
• create a layer of rock & mineral fragments
called regolith
• soil- part of the regolith that supports the
growth of plants; most fertile topsoil only goes
a foot or so deep
• changes over time

3. SOIL COLOR:
Red: iron oxides (rust)
Grey: elevated water tables & reduced iron
Black: organic material, manganese, iron sulfides
White: carbonate or salts
Yellow: goethite (type of iron) or pure sulfur
(rare)
VIDEO 1: Soil &
Forests 3 min
VIDEO 2: Topsoil
conservation 2 min

5. SOIL TEXTURE
determined by particle size
1. clay- smallest size
2. silt
3. sand
4. gravel- largest size

7. SOIL TEXTURE
1. clay
• smallest size
• slippery when wet
• long time to warm up & cool
• light weight; holds water & nutrients well
• doesn’t drain well may become
waterlogged

8. dry clay
wet clay

9. SOIL TEXTURE
2. silt
• small, between clay & sand size
• warms and cools more quickly than clay
• holds water but can be hard to drain
• holds limited nutrients

10. silt

11. SOIL TEXTURE
3. sand
• large particles
• gritty between your fingers
• warms quickly & cools quickly
• drains well (doesn’t hold water)
• cannot hold
nutrients

13. loam: combination of particle sizes ideal soil
form most plants
• about equal amounts of sand and silt
• smaller amount of clay
LAB Soil Texture by Feel LINK

16. SOIL COMPOSITION
Good Quality Soil has:
• 45% minerals & broken-down rock
• 5% organic matter (humus) that slowly
releases nutrients over time
• 25% water
• 25% air- fills in gaps
in soil allowing plants
& animals to
breathe

17. Healthy soils have living organisms that feed off
the organic matter and help stir and aerate the
soil
• insects
• bacteria
• earthworms
• burrowing animals

18. SOIL:
N: Nitrogen (green)
P: Phosphorous (root growth)
K: Potassium (flower)
pH: soil acidity or alkalinity
0--------------7--------------14
Acid Neutral Alkaline
Acid Acid
up down
Sulfur calcium
Aluminum lime
sulfate
http://www.biconet.com/te
sting/GIFs/st-t2.jpg
Most plants like pH between 5.5 and 7.5

19. SOIL FORMATION
• rate of soil formation = rate of weathering
• soil fertility = chemical makeup

20. CL, o, r, p, t
Cl: climate
O: organisms living in it (earthworms, fungus,
microbes- bacteria)
R: relief, slope of the land (think erosion &
deposition)
P: parent material (decayed material:
plants/animals; compost; rocks)
T: time (young, old soils)
http://www.hylandseeds.com/images/soil%20photo.jpg
Cl O R P T

21. ClCl O R P T
Climate- affects formation of soil
• variations in temperature and precipitation
influence rate, depth, & type of weathering
• hot, wet climate: lots of chemical
weathering
• cold, dry climate: thin mechanical
weathering
• precipitation affects rate at which nutrients
are leached from the soil
• affects organisms that live in the soil

22. OCl O R P T
Organisms- affects formation of soil
• types of organisms & how many there are
impact physical & chemical properties of soil
• some soils are name based on vegetation
• microorganisms break down organic matter
affecting fertility
• mix soil
• earthworm can mix thousands of
kilograms of soil; aeration

23. RCl O R P T
Relief- affects formation of soil
• slope of the land
• steep slopes-
• high erosion
• little water soaks in, less plants
• so soils are thin
• flat areas-
• low erosion, poor drainage
• deposition of sediments
• so soils are thick & dark

24. direction of slope
• South facing slopes (in N Hemisphere)
• more sunlight
• so: warmer, drier soils
• affects what plants grow there
• North facing slopes
• less sunlight
• so: cooler, wetter soils
• affects what plants grow there

25. PCl O R P T
Parent Material- affects formation of soil
• source of the mineral matter
• affects color & nutrient
• residual soil
• forms on bedrock
• transported soil
• forms on unconsolidated deposits,
materials moved from another location

26. TCl O R P T
Time- affects formation of soil
• how long the soil has be forming
• it takes up to 500 years to form 1 inch of soil
• longer time in formation
• thicker soil
• shorter time in formation
• thinner soil

27. SOIL TYPES
Pedalfer-
• forms in temperate areas that
receive more than 24 inches a year
• Eastern half of US
• forested areas
• B horizon- large
amounts of iron oxide
& aluminum rich clay
(brown-red color)

28. SOIL TYPES
Pedocal-
• drier climates
• western us
• grasses & brush vegetation
• less clay; chemical weathering is slower
• (light gray brown)

29. SOIL TYPES
Laterite-
• hot, wet tropical areas
• lots of chemical weathering
• deeper over shorter time
• no organic matter
• orange or red color
• used as bricks

31. SOIL PROFILE (Horizons)
A- Topsoil
B- Subsoil
C- partially weathered
parent material
Parent Material

32. A Horizon
B Horizon
C Horizon
O- Organic Material
E- Leaching of minerals
R- Parent Material

36. Agricultural Practices

37. Protecting Topsoil:
• Contour planting- tilling along
the contours of the land;
prevents water from running
down slopes, taking topsoil
with it
• Terracing- cutting flat steps
into slopes for flat planting
surfaces

38. • Crop rotation- plants remove nutrients from
the soil; by rotating what is grown
in fields each year and leaving a
field fallow (no farming) allows
minerals to replenish naturally in
the soil
• Rotate animals in fields- for fertilization
(sheep/goats,
chickens, crops)

39. • Green manure- planting cover crops for the
winter to keep the soil in place; in the spring,
till it under for nutrients
• Plant trees to protect from wind

40. • Manure & Compost: Organic fertilizer that
protects soil
• Plant matter
decays into
nutrient rich
compost
• Keep it turned & wet, worms & bacteria will do
the rest (HOT!)
• Lose the pesticides & herbicides: they kill the
pollinators and get into the soil and water

41. • Biodiversity- mix it up; when planting
monocultures (same crop) over large spaces of
land, natural ecosystem of decomposers,
pollinators, and such cannot thrive

42. Fertilizer: puts nutrients into the soil for plants
Chemical fertilizer: man-made mixture of
important nutrients (like in Miracle Gro)
1.(N) Nitrogen (helps plant stay green)
2.(P) Phosphorous (helps root growth)
3.(K) Potassium (helps flowering)
+
-direct nutrients
-quick feed
-easy
-
-long-term leaching of
soil
-runoff into waters

43. • Organic fertilizer: using a mixture of
decayed plant matter to supply needed
nutrients
1.Make a compost pile: pile up plant & food
scraps (not milk or meat!!)… all things that
decay.
2.Use manure, healthy Earthworms
+
-slow-release of
nutrients
-natural; no chemicals
-
-slower
-harder to do for
enormous farms

44. 1. What does Cl-orpt stand for? _______________________________________
2. How can you increase the acidity of your soil? _______________________
How can you lower the acidity of your soil? ______________________
Soil Infiltration Lab
Fill in the chart
describing each soil
sample. Be sure to
use good science
vocabulary.
Jar A Jar B Jar C
Location
Color
Structure
Texture
Infiltration
What do the
following three soil
nutrients do for the
plant?
1. Phosphorus(P)
_________________
2. Potassium (K)
_________________
3. Nitrogen (N)
_________________
Label the PH line below.
_________________________
0 7 14
________ ________ _______

45. SOIL TESTING LABS-
School Yard Samples
Soil Texture
1. How does the soil sample feel?
Circle the adjectives that describe your soil
grainy & gritty
smooth & silky
sticky when moist
maleable
2. Describe the particles: (mostly sand, silt, or
clay) ________________________
3. Where would the soil
sample be located on the
texture triangle? Color it.
clay
silty
clay
sandy
clay
clay
loam
sandy,
clay,
loam
silty,
clay,
loam
loam
silt
loam silt
Sandy,
loamsand
SAMPLE LOCATION:
_____________
pH Test
1. What was the pH of your soil sample? _____
2. How do you increase the pH of soil?
____________________________
3. How do you decrease the pH of soil?
____________________________
PAGE 1

46. 1. How could you increase your soil acidity?
___________________________
2. How could you decrease your soil acidity?
___________________________
3. Choose a crayon for each color sample. Make a key. Circle
some plants from the list that would prefer each soil type using
those crayons.
Crayon
color:
Soil
color
pH Yard location
Sample
1
Sample
2
Sample
3
Sample
4
Sample
5
Sample
6
pH Test
Alfalfa 6.0-7.0
Apple 5.5-6.5
Asparagus 6.0-7.0
Azalea 4.0-5.0
Banana 7.0
Beech 6.0-7.0
Beet 5.8-7.0
Broccoli 6.-7.0
Cabbage 6.0-7.0
Camelia 4.0-5.5
Carnation 6.0-8.0
Carrot 5.5-6.5
Cauliflower 6.0-7.0
Chestnut 5.0-6.0
Clover 6.0-7.0
Coleus 6.0-8.0
Corn 6.0-7.0
Cotton 5.5-6.5
Cucumber 6.0-8.0
Daffodil 6.0-6.5
Geranium 6.0-8.0
Holly 5.0-6.0
Lemon 5.5-7.0
Lima Bean 5.5-6.5
Maple 6.0-8.0
Mint 6.0-8.0
Orchid 5.0-6.0
Pea 6.0-8.0
Peanut5.0-6.0
Petunia 6.0-8.0
Potato 4.8-6.5
Radish 6.0-8.0
Rice 6.0-7.0
Rose 6.0-8.0
Spruce5.0-6.0
Strawberry 5.0-6.0
Tomato 6.0-7.0
Wheat 6.0-7.0
SOIL TESTING LABS-
School Yard Samples
PAGE 2

47. SOIL TESTING LABS-
GRASS SEEDS
pH Test
1. What was the pH of your soil sample? _____
2. How do you increase the pH of soil?
___________________________________________
3. How do you decrease the pH of soil?
___________________________________________Soil Texture
1. How does the soil sample feel?
Circle the adjectives that describe your soil
grainy & gritty
smooth & silky
sticky when moist
maleable
2. Describe the particles: (mostly sand, silt, or
clay) ________________________
3. Where would the soil
sample be located
on the texture
triangle?
Color it.
clay
silty
clay
sandy
clay
clay
loam
sandy,
clay,
loam
silty,
clay,
loam
loam
silt
loam silt
Sandy,
loamsand
Procedure: Add the following three variables to the three
soil samples: 1 tsp salt, 1 dropper acid, 1 tsp base.
Hypothesis: How do you think each added variable will
affect the grass seed?
-SALT: ____________________________ pH_____
-ACID: ____________________________ pH_____
-BASE: ____________________________ pH_____
-Which manipulation do you think will allow the grass
seed to grow the best? :_______________
-Which manipulation do you think will make the grass seed
grow the poorest? ______________
Observations
DAY 1 _____ DAY 2 _____ DAY 3 _____
Conclusions: What is your conclusion based on your
observations?

48. pH TEST STRIPS
Put your tested pH strips here:
Soil Sample (Control)
Acid (lemon Juice)
Base/Alkaline (Limestone powder)
Salt
pH TEST STRIPS
Put your tested pH strips here:
Soil Sample (Control)
Acid (lemon Juice)
Base/Alkaline (Limestone powder)
Salt

49. SOIL TESTING LABS
Nitrogen Test
1. Was the reacted sample pink?
_____________
2. What was the nitrogen level in your soil
sample?_________________
3. What does nitrogen do for plants?
_____________________________________
__
Potassium Test
1. Was the reacted sample cloudy?
_____________
2. What was the potassium level in your soil
sample?_________________
3. What does potassium do for plants?
_____________________________________
__
Phosphorus Test
1. Was the reacted sample blue?
_____________
2. What was the phosphorus level in your soil
sample?_________________
3. What does phosphorus do for plants?
___________________________
Soil Texture
1. How does the soil sample feel?
Circle the adjectives that describe your soil
grainy & gritty
smooth & silky
sticky when moist
maleable
2. Describe the particles: (mostly sand, silt, or
clay) ________________________
3. Where would the soil
sample be located on the
texture triangle? Color it.
clay
silty
clay
sandy
clay
clay
loam
sandy,
clay,
loam
silty,
clay,
loam
loam
silt
loam silt
Sandy,
loamsand
SAMPLE 1:
_____________

50. Directions:
1. Receive your yard location from the teacher. With your group, use a trowel
to dig two cupfuls of soil into your two specimen containers. You have 4
minutes.
2. Bring your specimens back to your table when the class reassembles.
3. Perform each of the 4 soil tests for the soil sample using the contents from
ONE cup. LISTEN TO MY INSTRUCTIONS FOR THIS. Keep the second
cup as a reference (control)– DO NOTHING TO IT.
4. Record your data. (nitrogen, phosphorus, potassium, pH & texture)
5. Leave the area neat, displaying the tested containers for the next group to
record.
6. Travel to the next station & observe the results of their soil tests.
7. Record your observations from each station. (Don’t forget pH.)
8. Complete any questions that you have not finished in your plant journal.
SOIL TESTING LABS