CFA Best Practices for Application Questions and Answers 1

Question 1

The 4R Nutrient Stewardship framework is a cornerstone of best practices for fertilizer application. What are the four "rights" that comprise this framework?

Accepted Answer

Right Source, Right Rate, Right Time, Right Place

Answer

The 4R Nutrient Stewardship concept provides a globally recognized framework for achieving cropping system goals by managing plant nutrients responsibly. The four core components are applying the Right Source of nutrients at the Right Rate, at the Right Time, and in the Right Place.

Question 2

An applicator is applying granular phosphorus fertilizer to a field that slopes gently towards a stream. To best protect water quality from nutrient runoff, which of the following actions is most critical?

Accepted Answer

Maintaining a mandatory or voluntary vegetated buffer strip where no fertilizer is applied.

Answer

Maintaining an unfertilized, vegetated buffer strip or setback from surface water bodies is a key best management practice. This strip helps to filter runoff and absorb nutrients before they can enter the stream, protecting water quality from contaminants like phosphorus. The other options are incorrect and could potentially worsen the environmental impact.

Question 3

A farmer is growing corn on a silt loam soil in a region that receives significant spring rainfall. To maximize nitrogen use efficiency and minimize the risk of leaching or denitrification, which nitrogen application strategy is most advisable?

Accepted Answer

Applying a smaller portion of nitrogen at or near planting, and the majority as a sidedress application when the corn is actively growing.

Answer

A split application, or sidedressing, synchronizes the application of the majority of the nitrogen with the period of maximum uptake by the corn crop. This approach reduces the amount of time the nitrogen is in the soil before the crop needs it, thus minimizing the potential for environmental losses through leaching or denitrification, especially in wet conditions.

Question 4

Which of the following is a primary agronomic advantage of banding a phosphorus (P) fertilizer near the seed row, especially in cool, low-testing soils?

Accepted Answer

It concentrates the immobile nutrient in a zone where it is more accessible to young plant roots.

Answer

Phosphorus is relatively immobile in the soil. Banding concentrates the P fertilizer in a specific zone close to developing roots, increasing the likelihood of root interception and uptake. This is particularly effective for promoting early-season growth in cool soils where nutrient availability and root growth are limited.

Question 5

An applicator surface-broadcasts urea (46-0-0) on a warm, moist, high-residue field. What is the most significant potential pathway for nitrogen loss if the urea is NOT incorporated into the soil shortly after application?

Accepted Answer

Volatilization

Answer

When urea is applied to the soil surface, it is converted to ammonium by the urease enzyme. This process can lead to the formation of ammonia gas, which is lost to the atmosphere. This pathway, known as volatilization, is most significant in warm, moist conditions. Incorporating the urea via tillage or rainfall places it in the soil where the ammonium can be held, preventing this loss.

CFA Practice Test

CFA Practice Test

CFA Best Practices for Application Questions and Answers 1