CH Plant Nutrition and Fertilization 2

Question 1

Fertilizer burn on plant roots is primarily caused by high concentrations of which factor?

Accepted Answer

Soluble salts

Answer

Excessive soluble salts from over-fertilization create a high-osmotic-potential environment that draws water out of root cells, causing burn.

Question 2

Which fertilizer application method places nutrients directly in the root zone with minimal surface waste?

Accepted Answer

Deep root injection

Answer

Deep root injection delivers liquid fertilizer directly into the active root zone, bypassing competition from turf and reducing runoff.

Question 3

Phosphorus in fertilizers is expressed as which chemical compound equivalent on the label?

Accepted Answer

P2O5

Answer

Federal law requires that phosphorus content on fertilizer labels be expressed as the oxide equivalent P2O5, even though modern soils labs report elemental P.

Question 4

A soil test reports low potassium. Which symptom would you most likely observe on affected plants?

Accepted Answer

Brown scorching along leaf margins of older leaves

Answer

Potassium deficiency typically causes marginal scorch (brown edges) on older, lower leaves because potassium is mobile and redistributed to younger tissue.

Question 5

Which nutrient application timing is most appropriate for promoting flower and fruit development?

Accepted Answer

High phosphorus prior to flowering

Answer

Phosphorus supports energy transfer (ATP) and promotes flower initiation and fruit set, making pre-bloom application the optimal timing.

CH - Certified Horticulturist Practice Test

CH - Certified Horticulturist Practice Test

CH Plant Nutrition and Fertilization 2