First things First
1.
Locate your rock sample from yesterday.
2.
Take a small piece off and tape over in into your
lab notebook.
3.
Make a bubble – “Describe how rock can
change and form into new rock”
•
Be sure to use the three vocabulary words –
sedimentary, metamorphic, and igneous.
Plant & Soil Science
Introduction to Soil Fertility and pH
with Soil Sampling Lab
Slide #2
Most popular macronutrients in soil
•Nitrogen------N
•Phosphorus-----P
(usually in the form of P2O5)
•Potassium-------K
(usually in the form of K2O)
Slide #3
What does nitrogen do?
• Most popular macronutrient
• It give a plant it’s green color
• Assists with rapid growth and vigor
• Promotes seed and fruit development
• Increases protein and yield
Slide #4
Phosphorous (P2O5) is important why?
•Aids seedlings to germinate
• Very important in the early stages of the
crop
• Stimulates root growth
Slide #5
What does Potassium (K20) do?
•Responsible for production of
carbohydrates in the plant,
•Produces plumper seeds
•Acts as the water valve for letting water in
and out of the plant.
Slide #13
What is pH?
pH is the scale we use to measure acidity
(sour) to basic (bitter).
What is the range of pH?
You are right the range is 0-14.
pH Scale
•Bases start at 7.1 and go to 14
•Acids start with zero and go to 6.9
“B” comes after “A”
“A” begins the alphabet
Slide #14
Slide #15
What does pH measure?
pH is the measure of how an item reacts with water.
If it gives off hydrogen ions (H+) it is an acid.
An example would be hydrochloric acid. When it meets
water it forms hydrogen ions and chloride ions.
A base give off hydroxide ions when reacting with
water.
Sodium hydroxide is a base because it forms sodium ions
and hydroxide ions when mixed with water.
Slide #16
Why do we need to know pH?
Knowing the pH of our soil is important for
two reasons:
It allows us to figure what amendments we
might need to make the soil more efficient for
the crop we are to be growing
It also determines nutrient availability (some
nutrients become unavailable to plants at low
or high pH levels)
Make a chart in your lab
notebook – use your resources
Soil
Function in What happens in What happens when
Characteristic
Plants
Excess
depleted
Nitrogen
Potassium
Phosphorus
pH
Source of
Evidence