CCA Nutrient Management 2

Question 1

Which soil pH range is generally considered optimal for maximizing phosphorus availability to most agronomic crops?

Accepted Answer

6.0–7.0

Answer

Phosphorus availability peaks between pH 6.0 and 7.0, where it is least likely to be fixed by aluminum, iron, or calcium.

Question 2

A field soil test reveals a cation exchange capacity (CEC) of 25 meq/100g. Compared to a soil with CEC of 5 meq/100g, this soil will:

Accepted Answer

Retain more cations against leaching

Answer

Higher CEC soils have more negatively charged sites that hold cations such as Ca²⁺, Mg²⁺, and K⁺, reducing leaching losses.

Question 3

The '4R' nutrient stewardship framework stands for applying the right nutrient at the right:

Accepted Answer

Rate, time, place, and source

Answer

The 4Rs are: right source, right rate, right time, and right place, forming the foundation of responsible nutrient management.

Question 4

Luxury consumption of potassium is most likely to occur in which crop?

Accepted Answer

Alfalfa

Answer

Alfalfa is well known for luxury potassium uptake, absorbing K far beyond its physiological needs when soil K is high.

Question 5

Which of the following is a primary advantage of split nitrogen applications compared to a single pre-plant application?

Accepted Answer

Lowers the risk of leaching and denitrification losses

Answer

Splitting N applications synchronizes supply with crop demand, reducing the window during which N is vulnerable to loss pathways.

(CCA) Certified Crop Advisor Practice Test