Fertilizer Application Techniques & Equipment Flashcards

A producer is applying 28% UAN solution through a coulter-injection system. The main safety concern specific to this equipment is:

Answer: Pressure line failure causing skin and eye contact with corrosive liquid

Liquid fertilizer injection systems operate under pressure, and hose or fitting failures can cause UAN solution to spray onto operators, causing chemical burns to skin and eyes.

Which boom height setting produces the best spray overlap and uniformity for a flat-fan nozzle rated for 110° spray angle?

Answer: Height achieving 100% overlap at the nozzle spacing used

Flat-fan nozzles require specific boom heights to achieve the designed overlap (typically 100%) at the nozzle spacing; the manufacturer's chart pairs spray angle, spacing, and height.

Side-dress nitrogen application is typically timed to coincide with which crop growth stage for corn?

Answer: V4 to V6 (4 to 6 leaf collar stage)

Side-dressing between V4 and V6 places nitrogen in the soil shortly before the rapid corn growth phase when demand increases sharply, improving efficiency.

A yield map from a field shows consistent low yield in parallel strips spaced 30 feet apart. The most probable cause is:

Answer: Spreader skip rows from incorrect swath width or overlap

Regularly spaced, parallel low-yield strips matching the applicator working width are a classic sign of missed swath or insufficient overlap during fertilizer application.

When applying phosphorus fertilizer by banding at planting, the recommended placement to avoid seed injury is:

Answer: 2 inches to the side and 2 inches below the seed (2x2 placement)

The 2x2 (or 2-inch side, 2-inch below) placement positions nutrients close enough for early root access while avoiding the salt injury that can occur with in-furrow application at high rates.

Which factor most directly determines the application width of an aerial fertilizer application?

Answer: Swath width established during calibration flights with spread pattern testing

Aerial swath width is determined during calibration using spread boards or cards on the ground to measure actual distribution width and uniformity for the specific product and aircraft setting.

Fertigation through a drip irrigation system requires which critical safety device to protect the water supply?

Answer: Backflow prevention device (check valve or injection into pressurized line downstream of source)

A backflow prevention device is mandatory to stop fertilizer solution from siphoning back into the water source (well, pond, or municipal supply) when pressure drops.