CH Plant Nutrition and Fertilization 3

Question 1

Which fertilization practice is recommended to reduce nutrient runoff into waterways in the US?

Accepted Answer

Use split applications and slow-release products

Answer

Split applications and slow-release products reduce nutrient loading in runoff by limiting the amount of soluble nutrients present in the soil at any one time.

Question 2

Which micronutrient deficiency causes 'little leaf' or 'rosette' symptoms in fruit trees and ornamentals?

Accepted Answer

Zinc

Answer

Zinc deficiency causes shortened internodes and clustered small leaves ('little leaf' or 'rosette') because zinc is required for auxin synthesis.

Question 3

The cation exchange capacity (CEC) of a soil influences its ability to:

Accepted Answer

Retain and supply positively charged nutrients

Answer

CEC measures how many cations (Ca²⁺, Mg²⁺, K⁺, NH₄⁺) a soil can hold on negatively charged exchange sites, directly affecting nutrient retention.

Question 4

Foliar fertilization is most effective for correcting deficiencies of which type of nutrients?

Accepted Answer

Immobile micronutrients such as iron and manganese

Answer

Foliar sprays are particularly effective for immobile micronutrients like iron, manganese, and zinc because they bypass soil chemistry issues that limit uptake.

Question 5

Compost is valued as a soil amendment partly because it improves nutrient retention. This is mainly due to its contribution of:

Accepted Answer

Cation exchange capacity via humus

Answer

The humic substances in finished compost carry significant negative charge, increasing CEC and the soil's ability to hold cations against leaching.

CH - Certified Horticulturist Practice Test

CH - Certified Horticulturist Practice Test

CH Plant Nutrition and Fertilization 3