FREE CFA Nutrient Cycling Principles Questions and Answers

Question 1

Which of the following best describes the role of decomposition in nutrient cycling within an agricultural ecosystem?

Accepted Answer

It releases inorganic nutrients from organic matter, making them available for plant uptake.

Answer

It primarily contributes to the loss of nutrients from the soil through leaching.

Answer

It converts atmospheric nitrogen into a form usable by plants.

Answer

It is the main process responsible for nutrient uptake by plant roots.

Question 2

A farmer observes signs of nitrogen deficiency in a field, despite recent organic matter additions. A soil test reveals high carbon-to-nitrogen ratio. Which principle of nutrient cycling is most likely at play?

Accepted Answer

Nitrogen immobilization by soil microbes.

Answer

Excessive nitrogen leaching due to heavy rainfall.

Answer

Phosphorus fixation in alkaline soils.

Answer

Potassium luxury consumption by plants.

Question 3

Which nutrient cycling process is most significantly impacted by the presence of legumes (e.g., alfalfa, clover) in a crop rotation?

Accepted Answer

Nitrogen fixation.

Answer

Phosphorus mineralization.

Answer

Potassium adsorption.

Answer

Sulfur oxidation.

Question 4

A fertilizer applicator is developing a nutrient management plan for a field with sandy soil and high rainfall. Which nutrient is most susceptible to significant loss via leaching under these conditions?

Accepted Answer

Nitrate-nitrogen (NO3-).

Answer

Immobilized phosphorus (P).

Answer

Adsorbed potassium (K+).

Answer

Organic nitrogen.

Question 5

In a healthy soil ecosystem, what is the primary mechanism by which phosphorus becomes available for plant uptake from organic matter?

Accepted Answer

Mineralization, primarily by microbial activity.

Answer

Atmospheric deposition following lightning strikes.

Answer

Direct absorption of phosphorus gas by roots.

Answer

Volatilization from the soil surface.

Question 6

Which of the following processes represents a loss of nitrogen from the agricultural soil system into the atmosphere?

Accepted Answer

Denitrification.

Answer

Nitrification.

Answer

Ammonification.

Answer

Mineralization.