FREE CFA Soil Analysis Interpretation Questions and Answers

Question 1

A soil test report indicates a pH of 5.2. For optimal growth of most common field crops, what amendment would typically be recommended to correct this soil acidity?

Accepted Answer

Agricultural lime (calcium carbonate)

Answer

Gypsum (calcium sulfate)

Answer

Elemental sulfur

Answer

Urea (nitrogen fertilizer)

Question 2

A farmer receives a soil test report showing very high phosphorus (P) levels (above critical range) and adequate potassium (K). The upcoming crop is corn, which has a moderate P and K demand. Based on this interpretation, what would be the most appropriate fertilizer recommendation for P and K for the next growing season?

Accepted Answer

Apply no P and no K.

Answer

Apply a maintenance dose of P and K.

Answer

Apply only P, no K.

Answer

Apply only K, no P.

Question 3

Which of the following soil test parameters provides the best indication of a soil's ability to hold and exchange positively charged nutrient ions?

Accepted Answer

Cation Exchange Capacity (CEC)

Answer

Organic matter content

Answer

Electrical Conductivity (EC)

Answer

Bulk density

Question 4

A soil analysis indicates an Electrical Conductivity (EC) reading of 4.5 dS/m. For most common agricultural crops, what does this reading primarily suggest?

Accepted Answer

The soil likely has high salinity.

Answer

The soil has a low buffering capacity.

Answer

The soil is highly acidic.

Answer

The soil is deficient in micronutrients.

Question 5

A soil test report shows low levels of zinc (Zn) and iron (Fe) in a high pH soil. Which of the following statements best explains why these micronutrients might be less available for plant uptake under these conditions?

Accepted Answer

High pH causes Zn and Fe to form insoluble compounds, reducing their availability.

Answer

High pH increases the solubility of Zn and Fe, leading to leaching.

Answer

Microbial activity is reduced in high pH soils, limiting nutrient cycling.

Answer

High pH directly inhibits plant root uptake mechanisms for these nutrients.

Question 6

When interpreting a soil test, if the 'Mehlich-3 P' value is reported as 'Very High', what is the most scientifically sound recommendation regarding phosphorus fertilization for the upcoming crop?

Accepted Answer

Eliminate phosphorus fertilizer application for the next growing season.

Answer

Apply phosphorus at a maintenance rate.

Answer

Apply phosphorus only if the crop yield goal is exceptionally high.

Answer

Apply phosphorus at a reduced rate compared to average recommendations.

A soil test report indicates a pH of 5.2.For optimal growth of most common field crops, what amendment would typically be recommended to correct this soil acidity?

A soil test report indicates a pH of 5.2.
For optimal growth of most common field crops, what amendment would typically be recommended to correct this soil acidity?