CFA Fertilizer Application Techniques & Equipment 3

Question 1

Variable rate technology (VRT) applicators rely primarily on which data source to adjust fertilizer rates across a field?

Accepted Answer

Prescription maps derived from soil sampling or remote sensing

Answer

VRT systems use GPS-referenced prescription maps created from soil test data, yield maps, or remote sensing to automatically adjust application rates zone by zone.

Question 2

When applying anhydrous ammonia, the minimum recommended soil moisture condition for effective sealing is:

Accepted Answer

Soil that is moist enough to close knife slots behind the applicator

Answer

Adequate soil moisture allows the disturbed soil to collapse and seal behind the knife, trapping anhydrous ammonia and preventing escape to the atmosphere.

Question 3

A rate controller on a variable rate applicator receives a new prescription zone but the gate position does not change. The most likely fault is:

Accepted Answer

Communication failure between the controller and the gate actuator

Answer

A communication failure between the rate controller and the gate/servo actuator prevents the mechanical adjustment needed to change output despite receiving the new prescription.

Question 4

Which fertilizer application scenario presents the highest risk of surface water contamination?

Accepted Answer

Broadcast application on frozen or saturated soil before rain

Answer

Fertilizer applied to frozen or saturated soil has no infiltration pathway and is highly susceptible to runoff into surface water when precipitation or snowmelt occurs.

Question 5

The purpose of using a urease inhibitor with surface-applied urea is to:

Accepted Answer

Slow the conversion of urea to ammonia, reducing volatilization

Answer

Urease inhibitors temporarily block the urease enzyme that converts urea to ammonium, giving time for rain or irrigation to move urea into the soil before volatile losses occur.

CFA Practice Test

CFA Practice Test

CFA Fertilizer Application Techniques & Equipment 3