FREE Certified Arborist Soil Management Questions and Answers

Question 1

Which of the following soil pH levels would give plants the greatest availability of iron?

Accepted Answer

5

Answer

Iron availability to plants is highly dependent on soil pH. Iron becomes less soluble and thus less available as the pH increases (becomes more alkaline). Therefore, a slightly acidic pH, such as 5, provides the greatest availability of iron for plant uptake, preventing iron chlorosis and ensuring proper plant nutrition.

Question 2

Which kind of bacteria are essential for the humus to be produced?

Accepted Answer

Actinomycetes

Answer

Actinomycetes are a group of bacteria that play a crucial role in the decomposition of complex organic matter in soil, such as cellulose and lignin. Their activity is essential for the formation of stable humus, which improves soil structure, water retention, and nutrient availability. They are often responsible for the characteristic earthy smell of healthy soil.

Question 3

After all gravitational water has drained and the soil has both accessible and unavailable water, what condition is it in?

Accepted Answer

Field capacity

Answer

Field capacity is the amount of water remaining in the soil after all gravitational water has drained away, typically 2-3 days after a thorough wetting. At this point, the soil holds the maximum amount of water available for plant uptake against the force of gravity, while some water is held too tightly for plants to access. It represents an optimal moisture level for plant growth.

Question 4

Leaching is known as:

Accepted Answer

The method by which water removes chemicals from soil.

Answer

Leaching is the process by which water percolates through the soil profile, dissolving and carrying away soluble nutrients, minerals, and other chemicals. This can be beneficial by removing excess salts, but it can also lead to the loss of essential plant nutrients from the root zone, especially in sandy soils or with excessive irrigation. It's a key process in nutrient cycling.

Question 5

What is resistance to changes in pH?

Accepted Answer

Buffering capacity

Answer

Buffering capacity refers to the ability of a soil to resist changes in its pH when acids or bases are added. Soils with high buffering capacity, often those rich in organic matter or clay, can neutralize these additions, maintaining a relatively stable pH. This stability is crucial for nutrient availability and microbial activity, which are sensitive to pH fluctuations.

Certified Arborist Test Practice Test

Certified Arborist Test Practice Test

FREE Certified Arborist Soil Management Questions and Answers