LO 5.0 - Outline soil fertility, and relate macro and micro elements to plant nutrition

Question 1

Question

A plant needs at least fifteen elements to grow and reproduce. How many can you name?

Give the name and Element symbol abbreviation.

Soil fertility, macro and micro

Answer 1

Macronutrients
* Nitrogen (N)
* Phosphorus (P)
* Potassium (K)
* Calcium (Ca)
* Magnesium (Mg)
* Sulfur (S)
* Carbon (C)
* Hydrogen (H)
* Oxygen (O)

Micronutrients
* Iron (Fe) (sometimes included with the macronutrients)
* Manganese (Mn)
* Copper (Cu)
* Boron (B)
* Zinc (Zn)
* Molybdenum (Mo)
* Chlorine (CI)

Soil fertility, macro and micro

Question 2

Question

Elements that are required by plants in relatively large amounts are called (________________)?

Soil fertility, macro and micro

Answer 2

Macronutrients
Each element has specific functions in the plant.
* The elements must be present in sufficient amounts and in forms usable by plants.

So-called because of the amounts required, not importance.

Soil fertility, macro and micro

Question 3

Question

Elements that are required by plants in smaller amounts are called (________________)?

Soil fertility, macro and micro

Answer 3

Micronutrients

Each element has specific functions in the plant.
* The elements must be present in sufficient amounts and in forms usable by plants.

So-called because of the amounts required, not importance.

Soil fertility, macro and micro

Question 4

Question

What does “Limiting factor” refer to?

Soil fertility, macro and micro

Answer 4

Limiting Factor
If all of the nutrients except one are present in amounts sufficient for plant growth, then growth will be no more than that one nutrient will allow.

Soil fertility, macro and micro

Question 5

Question

What does “Sufficiency range” refer to?

Soil fertility, macro and micro

Answer 5

Sufficiency range
As the amount of the limiting nutrient increases so that there is enough for optimal growth, it will reach what is known as the ‘sufficiency range’.

• At this point, adding more of that nutrient will not increase plant growth.

Adding more of that nutrient will not increase plant growth.

Soil fertility, macro and micro

Question 6

Question

What can happen if too much of a nutrient is added to soil?

Soil fertility, macro and micro

Answer 6

The plant may take up excess amounts and can start to show signs of toxicity (‘poisoning’).
* Rare with macronutrients.

It can lead to reduced growth and even death in extreme cases.

Soil fertility, macro and micro